IN THIS LESSON
This last chapter is a list of some of my favourite Microgreens Advanced Resources, including:
Best Microgreens Seeds Suppliers, per country
Recommend Microgreens Books
Best Microgreens Courses, per country
Most Complete, Definitive list of Microgreens varieties to grow
The Most comprehensive, Definitive list of Microgreens Academic and scientific research papers over the last 21 years
So once you've optimised how you grow Microgreens using the guidance on this page, and you still want to learn more, take your skills to the next level!
Last Updated with recent scientific research in March 2023
Best Microgreens Resources: Books
Here are a few books, podcasts, channels and website on how to grow Microgreens I can recommend – and have read!
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How Not To Die: Discover the Foods Scientifically Proven to Prevent and Reverse Disease
Grow Food for Free: The easy, sustainable, zero-cost way to a plentiful harvest
Microgreen Garden: The Indoor Grower's Guide to Gourmet Greens
Indoor Kitchen Gardening: Turn Your Home Into a Year-round Vegetable Garden
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Microgreens by Lisa Welsch at Vitality Farms
Growing Microgreens Podcast
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I encourage you to check other other Microgreens enthusiasts and learn from them too:
Best YouTube channels:
Best Microgreens websites:
Growing Microgreens in Egypt with Magrows (website in Arabic)
Best Microgreens Resources: Courses
It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.
Microgreens courses in UK.
It all begins with an idea. Maybe you want to launch a business. Maybe you want to turn a hobby into something more. Or maybe you have a creative project to share with the world. Whatever it is, the way you tell your story online can make all the difference.
Microgreens courses in US.
Best practical training I've found so far is at City Hydro and don't miss Larry Hountz' extremely useful youtube channel
Growing Microgreens for business and pleasure by Alex Field
GroCycle courses
Princeton Microgreens‘ video series
Home Microgreens Course by Chris Thoreau
Microgreens Farmer course by Nate Dodson
See a great video by John @GrowingYourGreens introducing Larry Hountz, from whom I've learnt so much!
Microgreens courses in EU.
InstaGreen (Spain)
ReactGreens (Slovenia – highly recommended!)
SmartFarmers (Belgium)
Best Microgreens Seeds Suppliers:
Where to buy Microgreens Seeds
I recommend these suppliers which I've reviewed and filtered based on a few key criteria suitable for growing microgreens at home – if you know of another good supplier, please let me know so I add here!
Make sure to buy organic Microgreens seeds: it's critical to use organic seeds (there will be some “organic” label or description on the packet, grown from parents without pesticides or herbicides or chemical fertilisers, and untreated with no chemical coatings, fungicides or other treatments applied to the seeds; it's simply unnecessary and harmful to the our planet, and to your family.
Buy high-quality seeds: from the suppliers below, you should expect high quality seeds with high germination rate which is important not to only to make the most of your money from the seeds you bought, but also to avoid spreading mold from non-germinating seeds to the rest of your tray.
Make sure to buy heirloom, open pollinated varieties: so you can keep seeds to produce “childrens” that grow well and resemble the “parents”!
Try buying in smaller batches: not too small though, otherwise you'll increase seeds transport footprints to restock, but it will avoid issues preserving seeds. Always check the date of harvest on the packet which will tell you if seeds are likely to germinate.
Don't poison yourself and your family: not all seeds are suitable for Microgreens and eating raw, for example don't grow tomatoes as Microgreens!
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Despite some challenges post brexit with, we are lucky to have quite a few great local suppliers!
Natures Root (easy orders on Amazon)
Real Seeds (a great small business who work hard on seeds preservations)
Pennard Plants (I LOVE their seeds packaging, varied Vegs and plants!)
sowfresh.com
SowSeeds.com
Aconbury Sprouts (Wheatgrass specialists)
Wild Greens Farm
Moles Seeds
Dutch Garden Seeds
Nicky's Nursery
Bloomling
Marshalls
SkySprouts Organics
Victoriana Nursery
WestlandsUK
TeenyGreeny
CN Seeds
BargainSeeds
Premier Seeds Direct
Franchi Seeds (not many microgreens here but many other edible flower seeds and many other great Vegs – and emails I look forward to!
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Safe Seed Pledge signatories: I try to recommend suppliers (US in particular) who signed up to Safe Seed Pledge which set out these commitments: Agriculture and seeds provide the basis upon which our lives depend. We must protect this foundation as a safe and genetically stable source for future generations. For the benefit of all farmers, gardeners and consumers who want an alternative, we pledge that we do not knowingly buy or sell genetically engineered seeds or plants. The mechanical transfer of genetic material outside of natural reproductive methods and between genera, families or kingdoms, poses great biological risks as well as economic, political and cultural threats. We feel that genetically engineered varieties have been insufficiently tested prior to public release. More research and testing is necessary to further assess the potential risks of genetically engineered seeds.
Trueleafmarket.com (highly recommended)
Johnnyseeds.com
SproutPeople (Sprouts specialists)
Tood's Seeds (non-gmo, chemical free, heirloom seeds)
Bootstrapfarmer.com
Urban Farmer (inc some unusual varities)
kitazawaseed.com, specialising in Asian Vegs seeds
PineTree Garden Seeds, caring much about non-GMO,
Highmowingseeds.com
SeedsNow (very focused on seeds not genetically modified or chemically altered)
Soluna Seeds
Everwilder Farms (great collection!)
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Natures Root (easy orders on Amazon)
AmoSeeds (inc plenty of unusual varieties)
Graines Baumaux (amazing variety of Vegs here too!)
BienManager
MicroPlants Robert (more unusual varieties)
De Germe En Pousse
Colette Graines (superbe quality!)
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Kiepenkerl
MP Seeds
Microgreen Shop
HeimGart
Vital Microgreens
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The home of horticulture!
Dutch Garden Seeds
DeBolster
DePeuleschil
Grown
BabyGreens
Little Plant Plantry
Check out equipment at DeSjop too!
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allthatgrows.in
BloomingGreens (fresh Microgreens & Wheatgrass)
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Irish Seed Savers
Seedaholic
Brown Envelope Seeds
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Bavicchi
SubaSeeds (great collection!)
ItalianSprouts (many unusual varieties too!)
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InstaGreen (and also courses and home grow kits)
Natures Root (easy on Amazon)
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Growing Microgreens can be difficult in some countries, in particular due to outside temperature (or even indoor temperature); and also finding the necessary supplies.
If you are trying to grow Microgreens in Egypt, check out Magrows who has learnt how to deal with those challenges! (website in Arabic)
If you want to grow Microgreens for profit, see our Microgreens friends at ReactGreen who maintain a list of potential bulk suppliers.
The Most Complete, Definitive list of Microgreens seeds to grow
If you are wondering what Microgreens to grow, we've put together a comprehensive list of 109 Microgreens, I still find new ones to try from time to time; do let me know if you can suggest any others!
Caution!
While there is a long list of Microgreens you can grow, a good rule to remember is that you should not eat plants you wouldn’t eat when mature – such as tomatoes, part of nightshade family and poisonous!.
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For your first few trays, I'd recommend you start with these (and where you can, choose red coloured ones for more anti-oxydants) :
Radish (+ super quick!)
Broccoli (given the health benefits!)
Kale
Kohlrabi (one of my favourite)
Beetroot
Red Cabbage
Arugula
Sundflow
Peas
Then you experiment with Microgreens colours, tastes from the list below!!
You can order most of those seeds below from the list of suppliers I recommend
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Adzuki bean
Alfalfa
Amaranth (Red or Malt)
Anise
Arugula (pepper)
Asparagus
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Barley
Basil
Beet
Borage
Broccoli
Brussel sprouts
Buckwheat
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Cabbage (red and green)
Carrot
Cauliflower
Celery
Celosia
Chard
Chervil
Chia
Chickpea
Chicory
Chinese Toon
Chives
Chrysanthemum
Cilantro
Clover
Collard
Corn salad (Mache)
Corn (pop!) – super fast!
Cress
Cucumber
Cumin (black) – nigella sativa
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Daikon
Dandelion
Dill
Dun pea
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Endive
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Fava beans
Fennel
Fenugreek
Flax
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Let me know if you find some!
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Hemp
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Let me know if you find some!
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Let me know if you find some!
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Kale
Kohlrabi
Komatsuna
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Leek
Lemon Balm
Lemongrass
Lemon mint
Lentils
Lettuce
Lovage
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Mache (corn salad)
Magenta Spreen
Mahogany (Chinese)
Marigold
Marjoram
Melon
Mint
Millet
Mizuna (Love!)
Moringa Oleifera
Mung Bean
Mustard
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Nasturtium
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Onion (red in particular!)
Orach
Oregano
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Parsley
Pak Choi
Paracress
Pea
Pumpkin seed
Purslane
Peppercress
Peppermint
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Quinoa
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Radish (super fast!)
Red Rain
Roselle (Hibiscus Sabdariffa L.)
Rutabaga
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Sage
Salad Burnet
Saltwort
Salsify
Sambuc
Savory
Scallions
Sea bean (samphire)
Sesame
Shiso (Britton)
Shungiku (Glebionis carinata)
Sorrel (veined sorrel)
Spearmint
Spinach
Spring Onion
Sunflower
Swiss Chard
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Tangerine
Tarragon
Tatsoi
Thyme
Tokyo Bekana (loose head chinese cabbage from Japan brasssica rapa pekinsensis group)
Triticale
Turnip
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Let me know if you find some!
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Let me know if you find some!
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Wasabi
Water Pepper
Wheatgrass
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Let me know if you find some!
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Let me know if you find some!
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Let me know if you find some!
Learn more: The Most comprehensive, Definitive list of Microgreens scientific research papers
Yes, I really read all these research papers – so you don't have to! – to make sure this Guide gives you the evidence behind the information I share.
If you are a Geek like me, read on!
If you’ve written research which I haven’t spotted yet and would like me to highlight here, please let me know!
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The natural abundance of L-canavanine, an active anticancer agent, in alfalfa, medicago sativa (L.): L-Canavanine, a potentially toxic antimetabolite of L-arginine that is stored by many leguminous plants, has demonstrative antineoplastic activity against a number of animal-bearing carcinomas and cancer cell lines. This investigation evaluated the natural abundance of this anti-cancer compound in commercially available sprouts, and in ten varieties of the seed of alfalfa, Medicago Sativa (L.). Canavanine abundance in commercially grown sprouts varied according to the source; the young plant stored appreciable canavanine that ranged from 1.3 to 2.4% of the dry matter. Alfalfa seeds were also rich in this nonprotein amino acid as the canavanine content varied from 1.4 to 1.8% of the dry matter. On average, the tested seeds contained 1.54 ± 0.03% canavanine. Alfalfa seed canavanine content was comparable to the levels found in the seeds of representative members of the genus Canavalia , which are amongst the more abundance sources of this antimetabolite.
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Antioxidants in vegan diet and rheumatic disorders: Plants are rich naAntioxidants in vegan diet and rheumatic disorderstural sources of antioxidants in addition to other nutrients. Interventions and cross sectional studies on subjects consuming uncooked vegan diet called living food (LF) have been carried out. We have clarified the efficacy of LF in rheumatoid diseases as an example of a health problem where inflammation is one of the main concerns. LF is an uncooked vegan diet and consists of berries, fruits, vegetables and roots, nuts, germinated seeds and sprouts, i.e. rich sources of carotenoids, vitamins C and E. The subjects eating LF showed highly increased levels of beta and alfa carotenes, lycopen and lutein in their sera. Also the increases of vitamin C and vitamin E (adjusted to cholesterol) were statistically significant. As the berry intake was 3-fold compared to controls the intake of polyphenolic compounds like quercetin, myricetin and kaempherol was much higher than in the omnivorous controls. The LF diet is rich in fibre, substrate of lignan production, and the urinary excretion of polyphenols like enterodiol and enterolactone as well as secoisolaricirecinol were much increased in subjects eating LF. The shift of fibromyalgic subjects to LF resulted in a decrease of their joint stiffness and pain as well as an improvement of their self-experienced health. The rheumatoid arthritis patients eating the LF diet also reported similar positive responses and the objective measures supported this finding. The improvement of rheumatoid arthritis was significantly correlated with the day-to-day fluctuation of subjective symptoms. In conclusion the rheumatoid patients subjectively benefited from the vegan diet rich in antioxidants, lactobacilli and fibre, and this was also seen in objective measures.
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The effect of fruit and vegetable intake on risk for coronary heart disease:
Background: Many constituents of fruits and vegetables may reduce the risk for coronary heart disease, but data on the relationship between fruit and vegetable consumption and risk for coronary heart disease are sparse.
Objective: To evaluate the association of fruit and vegetable consumption with risk for coronary heart disease.
Design: Prospective cohort study.
Setting: The Nurses' Health Study and the Health Professionals' Follow-Up Study.
Participants: 84 251 women 34 to 59 years of age who were followed for 14 years and 42 148 men 40 to 75 years who were followed for 8 years. All were free of diagnosed cardiovascular disease, cancer, and diabetes at baseline.
Measurements: The main outcome measure was incidence of nonfatal myocardial infarction or fatal coronary heart disease (1127 cases in women and 1063 cases in men). Diet was assessed by using food-frequency questionnaires.
Results: After adjustment for standard cardiovascular risk factors, persons in the highest quintile of fruit and vegetable intake had a relative risk for coronary heart disease of 0.80 (95% CI, 0.69 to 0.93) compared with those in the lowest quintile of intake. Each 1-serving/d increase in intake of fruits or vegetables was associated with a 4% lower risk for coronary heart disease (relative risk, 0.96 [CI, 0.94 to 0.99]; P = 0.01, test for trend). Green leafy vegetables (relative risk with 1-serving/d increase, 0.77 [CI, 0.64 to 0.93]), and vitamin C-rich fruits and vegetables (relative risk with 1-serving/d increase, 0.94 [CI, 0.88 to 0.99]) contributed most to the apparent protective effect of total fruit and vegetable intake.
Conclusions: Consumption of fruits and vegetables, particularly green leafy vegetables and vitamin C-rich fruits and vegetables, appears to have a protective effect against coronary heart disease.
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The scourge of” hidden hunger”: global dimensions of micronutrient deficiencies: the most recent estimates from FAO indicate that 840 million people do not receive enough energy from their diets to meet their needs. The overwhelming majority of these people–799 million–live in developing countries. The global toll of people affected by micronutrient deficiency is estimated to be even higher and probably exceeds two billion. Micronutrient deficiencies can exist in populations even where the food supply is adequate in terms of meeting energy requirements.
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Sulforaphane enhances aquaporin‐4 expression and decreases cerebral edema following traumatic brain injury
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Journal of Renal Nutrition: What You Should Know About Organic Foods: organic is good for you, and our planet.
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Food Enzyme Concept: Importance of Enzymes in Nutrition: In simple terms, enzymes contain the vitamin, the mineral and in Howell’s words “The enzyme complex harbors a protein carrier inhabited by a vital energy factor.” Only foods that are not cooked contain this vital energy factor—i.e. raw fruits and vegetables.
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Phenolic Compounds in Brassica Vegetables Phenolic compounds are a large group of phytochemicals widespread in the plant kingdom. Depending on their structure they can be classified into simple phenols, phenolic acids, hydroxycinnamic acid derivatives and flavonoids. Phenolic compounds have received considerable attention for being potentially protective factors against cancer and heart diseases, in part because of their potent antioxidative properties and their ubiquity in a wide range of commonly consumed foods of plant origin. The Brassicaceae family includes a wide range of horticultural crops, some of them with economic significance and extensively used in the diet throughout the world. The phenolic composition of Brassica vegetables has been recently investigated and, nowadays, the profile of different Brassica species is well established. Here, we review the significance of phenolic compounds as a source of beneficial compounds for human health and the influence of environmental conditions and processing mechanisms on the phenolic composition of Brassica vegetables.
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Assessment of Vitamin and Carotenoid Concentrations of Emerging Food Products: Edible Microgreens: Microgreens (seedlings of edible vegetables and herbs) have gained popularity as a new culinary trend over the past few years. Although small in size, microgreens can provide surprisingly intense flavors, vivid colors, and crisp textures and can be served as an edible garnish or a new salad ingredient. However, no scientific data are currently available on the nutritional content of microgreens. The present study was conducted to determine the concentrations of ascorbic acid, carotenoids, phylloquinone, and tocopherols in 25 commercially available microgreens. Results showed that different microgreens provided extremely varying amounts of vitamins and carotenoids. Total ascorbic acid contents ranged from 20.4 to147.0 mg per 100 g fresh weight (FW), while β-carotene, lutein/zeaxanthin, and violaxanthin concentrations ranged from 0.6 to 12.1, 1.3 to 10.1, and 0.9 to 7.7 mg/100 g FW, respectively. Phylloquinone level varied from 0.6 to 4.1 μg/g FW; meanwhile, α-tocopherol and γ-tocopherol ranged from 4.9 to 87.4 and 3.0 to 39.4 mg/100 g FW, respectively. Among the 25 microgreens assayed, red cabbage, cilantro, garnet amaranth, and green daikon radish had the highest concentrations of ascorbic acids, carotenoids, phylloquinone, and tocopherols, respectively. In comparison with nutritional concentrations in mature leaves (USDA National Nutrient Database), the microgreen cotyledon leaves possessed higher nutritional densities. The phytonutrient data may provide a scientific basis for evaluating nutritional values of microgreens and contribute to food composition database. These data also may be used as a reference for health agencies’ recommendations and consumers’ choices of fresh vegetables.
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Carotenoids and total phenolic contents in plant foods commonly consumed in Korea: Phytochemicals are reported to provide various biological functions leading to the promotion of health as well as the reduced risk of chronic diseases. Fat-soluble plant pigments, carotenoids, are extensively studied micronutrient phytochemicals for their potential health benefits. It is noteworthy that specific carotenoids may be responsible for different protective effects against certain diseases. In addition, each carotenoid can be obtained from different types of plant foods. Considering the fact that the phytochemical content in foods can vary according to, but not limited to, the varieties and culture conditions, it is important to establish a database of phytochemicals in locally produced plant foods. Currently, information on individual carotenoid content in plant foods commonly consumed in Korea is lacking. As the first step to support the production and consumption of sustainable local plant foods, carotenoids and total phenolic contents of plant foods commonly consumed in Korea are presented and their potential biological functions are discussed in this review.
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Microgreens: Assessment of Nutrient Concentration: Microgreens (seedlings of green vegetables and herbs) are gaining in popularity as a new culinary ingredient, providing intense flavors, vivid colors, and crisp texture when added to salads and other food preparations. Although microgreens would inherently be regarded as a healthy addition to the diet, no information is available on their nutritional content. The present study determined the concentrations of essential vitamins or provitamins A, C, E, and K1 in 25 commercially available microgreens. Results showed that different microgreens provide widely varying amounts of the four vitamins, but regardless they generally have significantly higher concentrations of these phytonutrients in comparison with mature leaves from the same plant species. These phytonutrient data provide the first scientific basis for evaluating nutritional benefits of microgreens and, when included in the USDA food composition database, can be used by health agencies and consumers to make educated choices about inclusion of microgreens as part of a healthy diet.
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Broccoli-Derived Sulforaphane and Chemoprevention of Prostate Cancer: From Bench to Bedside: Sulforaphane (SFN) is a metabolic by product of cruciferous vegetables and is the biologically active phytochemical found in high concentrations in broccoli. It has been studied extensively for its anticancer efficacy and the underlying mechanisms using cell culture and preclinical models. The immediate precursor of SFN is glucoraphanin, a glucosinolate which requires metabolic conversion to SFN. SFN and other notable isothiocyanates, including phenethyl isothiocyanate and benzyl isothiocyanate found in various cruciferous vegetables, have also been implicated to have a chemopreventive role for breast, colon and prostate cancer. In-vitro and in-vivo anti-cancer activity of this class of compounds summarizing the past two decades of basic science research has previously been reviewed by us and others. The present review aims to focus specifically on SFN and its chemopreventive and antineoplastic activity against prostate cancer. Particular emphasis in this communication is placed on the current status of clinical research and prospects for future clinical trials with the overall objective to better understand the clinical utility of this promising chemopreventive nutraceutical in the context of mechanisms of prostate carcinogenesis
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Evaluation and correlation of sensory attributes and chemical compositions of emerging fresh produce: Microgreens: Microgreens are popular and highly nutritious vegetable seedlings harvested at the ‘seed-leaf’ or cotyledon stage of maturity. Although many microgreens are considered highly flavorful their sensory attributes (flavor and taste profiles) have not been determined nor have their sensory profiles been related to their chemical compositions. We selected six microgreens varieties which differ in color, visual appearance, flavor, and taste, and correlated this sensory profile with their chemical and nutritional composition. All microgreens tested have “good” to “excellent” overall eating quality rated by consumer panelists, and each variety possess unique flavor and taste, e.g. astringency and bitterness (peppercress), heat (Dijon mustard), grassy (opal basil), sweetness (red amaranth and bull’s blood beet). This information will benefit microgreen growers by providing scientific information for consumers and chefs to select the right microgreens for their intended food pairing purposes, and market their products to the targeted customers, thus sustaining growth of the microgreen industry.
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Yield and quality of basil, Swiss chard and rocket microgreens grown in a hydroponic system: Microgreens are gaining interest for claimed high nutraceutical properties, but data on their chemical composition are so far limited. Although often grown hydroponically, their mineral requirements are still unknown. This study aimed to provide an insight into yield, mineral uptake, and quality of basil, Swiss chard, and rocket microgreens grown in a hydroponic system. With reference to data reported in literature for the same species hydroponically grown but harvested at adult stage, these microgreens yielded about half, with lower dry matter percentage, but higher shoot/root ratio. They showed high concentrations of some minerals, but their nutrient uptake was limited due to low yield. Nitrates content was lower if compared with that usually measured in baby leaf or adult vegetables of the same species, as well as the concentration of chlorophylls, carotenoids, phenols, and sugars. Therefore, microgreens seem to be interesting and innovative low-nitrate-salad crops requiring low fertiliser inputs. Nevertheless, an improvement in yield as well as in the content of nutraceutical compounds would be desirable.
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The effect of green leafy and cruciferous vegetable intake on the incidence of cardiovascular disease: A meta-analysis: Does the consumption of green leafy vegetables including cruciferous vegetables significantly reduce the incidence of cardiovascular disease? This research question was answered via employing the statistical methods of meta-analysis by synthesizing relevant worldwide studies that address the association between the consumption of green leafy vegetables and risk of incidence of said diseases. All meta-analysis calculations included determination of effect sizes of relative risk, and their respective 95% confidence intervals, heterogeneity of the studies, relative weights for each study, and significance (p) for each study. Eight studies met the inclusion criteria, which investigated the relationship between the incidences of total cardiovascular disease with the intake of green leafy vegetables. The overall effect size (random effect model) was: RR = 0.842 (95% CI = 0.753 to 0.941), p = 0.002, which indicates a significant 15.8% reduced incidence of cardiovascular disease.
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Environmental and cultural practices to optimise the growth and development of 3 Microgreens species: The recent popularity of edible microgreens (young seedlings of vegetable and herbs harvested shortly after emergence of the first true leaf) has resulted in increased interest of greenhouse growers to cultivate them for local markets. Their cultivation in hoop-houses, greenhouses and indoor production vertical farms (plant factories), permit growers control over growth parameters. This in turn allows growers to influence crop yield, morphology, days to harvest (DTH) and secondary metabolites, which hold perceived health benefits with consumers. Recommendations for their germination and growth parameters vary widely by seed supplier leaving growers to determine their own ideal cultural practices best suited for their operation. The use of horticultural lighting systems to hasten growth and promote the development of aromatic compounds in microgreens has also received little attention in the published literature. Therefore, it was the objective of this study to quantify the effects of four common cultural practices, four daily light integrals (DLI) and four carbon dioxide (CO2) concentrations on the growth, morphology, DTH and secondary metabolite production of three microgreen species: arugula (Eruca sativa L.), mizuna (Brassica rapa L. var. japonica) and mustard [Brassica. juncea (L.) Czern. ‘Garnet Giant’]. We began by evaluating four seed densities (1.1, 1.65, 2.2, 2.75 and 3.3 seeds•cm-2); five fertilizer concentrations (0, 50, 100, 150 or 200 mg N•L-1); four substrate depths (1.8, 3.3, 4.3 and 5.8 cm); and four air temperatures (14, 16, 20 and 22 °C) on fresh weight (FW), fresh weight per plant (FWPP), dry weight (DW), plant height and DTH. FW and FWPP were influenced in equal but opposite quadratic fashions as seed density increased from 1.1 to 3.3 seeds•cm-2 where total FW increased while FWPP decreased. FW increased in a quadratic fashion as both fertilizer concentration and substrate depth increased from 0 to 200 mg N•L-1 and 1.8 to 5.8 cm. DTH decreased linearly as air temperatures increased from 14 to 22 °C. After parameters were established for optimal cultural practices, we sought to quantify the effects of four DLI and four CO2 levels on the growth, morphology and secondary metabolite content of microgreens. Four levels of DLI (3, 6, 9 and 12 mol•m-2•d-1) by four levels of CO2 (400, 600, 800 and 1000 ppm) were evaluated under a full factorial design. FW increased linearly for mizuna and mustard as DLI and CO2 increased from 3 to 12 mol•m-2•d-1 and 400 to 1000 ppm. Arugula FW increased in a quadratic fashion as DLI increased from 3 to 12 mol•m-2•d-1 and linearly as CO2 increased from 400 to 1000 ppm. Dry weight increased linearly for all species as DLI and CO2 increased from 3 to 12 mol•m-2•d-1 and 400 to 1000 ppm. For mizuna and mustard, DTH decreased in a quadratic fashion while arugula DTH decreased linearly as DLI increased from 3 to 12 mol•m-2•d-1 with no observed influence from CO2. Total phenolics and total flavonoids increased linearly as DLI increased from 3 to 12 mol•m-2•d-1 where the effect of DLI on phenolic content was dependent on the CO2 level. The results of these studies can help growers determine optimal cultural practices to maximize yields, minimize production time and achieve a target crop size based on individual market demand. In addition, results can help growers conclude what combination of DLI and CO2 can achieve maximum yields at the lowest lighting energy input. Growers can then determine the importance of achieving maximum phenolic and flavonoid compounds and adjust light and CO2 as needed.
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National Center for Biotechnology Information: Broccoli Microgreens: A Mineral-Rich Crop That Can Diversify Food Systems: Current malnourishment statistics are high and are exacerbated by contemporary agricultural practices that damage the very environments on which the production of nutritious food depends. As the World’s population grows at an unprecedented rate, food systems must be revised to provide adequate nutrition while minimizing environmental impacts. One specific nutritional problem that needs attention is mineral (e.g., Fe and Zn) malnutrition, which impacts over two-thirds of the World’s people living in countries of every economic status. Microgreens, the edible cotyledons of many vegetables, herbs, and flowers, is a newly emerging crop that may be a dense source of nutrition and has the potential to be produced in just about any locale. This study examined the mineral concentration of broccoli microgreens produced using compost-based and hydroponic growing methods that are easily implemented in one’s own home. The nutritional value of the resulting microgreens was quantitatively compared to published nutritional data for the mature vegetable. Nutritional data were also considered in the context of the resource demands (i.e., water, fertilizer, and energy) of producing microgreens in order to gain insights into the potential for local microgreen production to diversify food systems, particularly for urban areas, while minimizing the overall environmental impacts of broccoli farming. Regardless of how they were grown, microgreens had larger quantities of Mg, Mn, Cu, and Zn than the vegetable. However, compost-grown (C) microgreens had higher P, K, Mg, Mn, Zn, Fe, Ca, Na, and Cu concentrations than the vegetable. For eight nutritionally important minerals (P, K, Ca, Mg, Mn, Fe, Zn, and Na), the average C microgreen:vegetable nutrient ratio was 1.73. Extrapolation from experimental data presented here indicates that broccoli microgreens would require 158–236 times less water than it does to grow a nutritionally equivalent amount of mature vegetable in the fields of California’s Central Valley in 93–95% less time and without the need for fertilizer, pesticides, or energy-demanding transport from farm to table. The results of this study suggest that broccoli microgreens have the potential to be a rich source of minerals that can be produced by individuals, even in urban settings, providing better access to adequate nutrition.
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Background: Nutritionally important carotenoids in 21-day-old brassica microgreens increase following short and long-term exposure to narrow-band wavelengths from light-emitting diodes (LED). The present study aimed to measure the impact of: (1) fluorescent/incandescent light and different percentages of blue/red LED light and (2) different levels of nutrient fertility on biomass and pigment concentrations in 30-day-old ‘Green Lance' Chinese kale (Brassica oleracea var. alboglabra). Kale plants were exposed to four light treatments and two fertility levels and were harvested 30 days after seeding and analyzed for nutritionally important shoot pigments.
Results: Kale under the fluorescent/incandescent light treatment had a significantly higher shoot fresh and dry mass. The shoot tissue concentrations of most pigment were significantly higher under blue/red LED light treatments. The higher fertility level resulted in higher concentrations for most pigments. Interestingly, the pool of xanthophyll cycle pigments and de-epoxidized xanthophylls was higher under all LED treatments.
Conclusion: The results obtained in the present study support previous data demonstrating the stimulation of nutritionally important shoot tissue pigment concentrations following exposure to sole source blue/red LEDs compared to traditional lighting. Xanthophyll cycle flux was impacted by LEDs and this may support the role of zeaxanthin in blue light perception in leafy specialty crops. © 2016 Society of Chemical Industry
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Dietary anti-cancer compound may work by influence on cellular genetics : Sulforaphane, a dietary compound from broccoli that's known to help prevent prostate cancer, may work through its influence on long, non-coding RNAs, report scientists. This is another step forward in a compelling new area of study on the underlying genetics of cancer development and progression.
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Nutritional characterization and shelf-life of packaged microgreens: Besides the variety of colours and flavours, microgreens show interesting nutritional properties, mainly regarding their contents of mineral nutrients and bioactive compounds. To date, the literature has prevalently focused on the individual nutritional features of microgreens usually belonging to Brassicaceae. The present study reports an articulated nutritional profile of six genotypes of microgreens, belonging to three species and two families: chicory (Cichorium intybus L., Puglia's local variety ‘Molfetta’, CM, and cultivar ‘Italico a costa rossa’, CR) and lettuce (Lactuca sativa L. Group crispa, cultivar ‘Bionda da taglio’, LB, and ‘Trocadero’, LT), from Asteraceae; and broccoli (Brassica oleracea L. Group italica Plenk, Puglia's local variety ‘Mugnuli’, BM, and cultivar ‘Natalino’, BN) from Brassicaceae. All the microgreens, except LB, can be considered good sources of Ca, whilst LT and CM also showed considerable amounts of K. As regards bioactive compounds, Brassica microgreens were the richest in phenolic antioxidants. The microgreens also presented higher amounts of α-tocopherol and carotenoids compared to mature vegetables. In particular, broccoli microgreens and LB showed the highest amounts of vitamin E, while Asteraceae microgreens presented the highest levels of carotenoids. Due to their delicate tissues, fresh cut microgreens showed a shelf life not exceeding ten days at 5 °C. The results obtained highlight the possibility to exploit genetic biodiversity in order to obtain tailored microgreens with the desired nutritional profiles, with particular regard to mineral nutrients and bioactive compounds. Appropriate pre- and post-harvest strategies should be developed, so as to allow microgreens to retain as long as possible their nutritional value.
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Virginia Tech: Effects of Seed Density and Other Factors on the Yield of Microgreens Grown Hydroponically on Burlap: Microgreens are gaining popularity as a new, nutritious salad crop. Growing microgreens in stacked hydroponic channels may improve efficiency and food safety for microgreens. However, differences between soil and hydroponic production methods for microgreens are not well known, especially when it comes to specific factors, like seed density, light exposure and yield for all the crops used as microgreens. This study explored the yield of six types of microgreens grown on burlap during three years of commercial production in a small educational greenhouse. The varieties, or species, tested in this study included basil, arugula, carrot, and blends of brassicas, radish and mustard. Seeds were sown directly on a single layer of burlap in a hydroponic nutrient film technique (NFT) system. Fresh weights (FW) of the microgreens were recorded after harvest to track the influence of seed density, light levels, growth time and season.
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ACS Publications: The Science Behind Microgreens as an Exciting New Food for the 21st century: Chronic diseases are a major health problem in the United States. Accumulated data suggest that consumption of vegetables can significantly reduce the risk of many chronic diseases. Dietary guidelines for 2015–2020 from the U.S. Department of Agriculture and the U.S. Department of Health and Human Services recommend 1–4 cups of vegetables per day for males and 1–3 cups of vegetables per day for females, depending on their age. However, the average intake of vegetables is below the recommended levels. Microgreens are young vegetable greens. Although they are small, microgreens have delicate textures, distinctive flavors, and various nutrients. In general, microgreens contain greater amounts of nutrients and health-promoting micronutrients than their mature counterparts. Because microgreens are rich in nutrients, smaller amounts may provide similar nutritional effects compared to larger quantities of mature vegetables. However, literature on microgreens remains limited. In this Review, we discuss chemical compositions, growing conditions, and biological efficacies of microgreens. We seek to stimulate interest in further study of microgreens as a promising dietary component for potential use in diet-based disease prevention.
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Vegetable Microgreens Farming in High-Altitude Region of Trans-Himalayas to Maintain Nutritional Diet of Indian Troops: Vegetables that are the source of nutritional diet are highly perishable, cannot travel very long and may lose nutritional value within a few days as compared to the fresh ones. Supply of fresh food products to remote locations of the country is a serious concern, and a large proportion of the Indian army is deployed in harsh conditions of high altitudes where food and nutritional security of the soldiers remain a sincere issue for long. Under such situations, microgreen vegetables can be helpful to diversify and enhance the nutrient content of the diet in remote locations where fresh food availability is a common constraint due to seasonal variability and the technological backwardness of the region. Microgreens are the tender green immature tiny plants having two fully developed cotyledon leaves with or without the emergence of a rudimentary pair of the first true leaves. Microgreens are considered as functional food which possesses phytonutrients having health-promoting benefits and antioxidant potential. Microgreen vegetables could be a good alternative of high-value food against various disorders common in high altitudes. Keeping in mind local conditions and resources available in remote areas, a multilayer unit of growing microgreens is adopted by the Defence Institute of High Altitude Research, Leh Ladakh. Vegetables suitable for microgreens cultivation in the region are radish, cabbage, cauliflower, broccoli, red cabbage, knol khol and fenugreek.
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Evaluation of the Bioaccessibility of Antioxidant Bioactive Compounds and Minerals of Four Genotypes of Brassicaceae Microgreens: Microgreens constitute an emerging class of fresh, healthy foods due to their nutritional composition. In this study the content of minerals and antioxidant bioactive compounds, and for the first time bioaccessibility, were evaluated in broccoli (Brassica oleracea L. var. italica Plenck), green curly kale (Brassica oleracea var. sabellica L.), red mustard (Brassica juncea (L.) Czern.) and radish (Raphanus sativus L.) hydroponic microgreens. Macro- (K, Ca, Mg) and oligo-elements (Fe, Zn), ascorbic acid, total soluble polyphenols, total carotenoids, total anthocyanins, total isothiocyanates and total antioxidant capacity (Trolox Equivalent Antioxidant Capacity and Oxygen Radical Absorbance Capacity) were determined before and after the standardized simulated gastrointestinal digestion process. All microgreens provided relevant amounts of vitamin C (31–56 mg/100 g fresh weight) and total carotenoids (162–224 mg β-carotene/100 g dry weight). Mineral content was comparable to that normally found in hydroponic microgreens and the low potassium levels observed would allow their dietetic recommendation for patients with impaired kidney function. Both total soluble polyphenols and total isothiocyanates were the greatest contributors to the total antioxidant capacity after digestion (43–70% and 31–63% bioaccessibility, respectively) while macroelements showed an important bioaccessibility (34–90%). In general, radish and mustard presented the highest bioaccessibility of bioactive compounds and minerals. Overall, the four hydroponic Brassicaceae microgreens present a wide array of antioxidant bioactive compounds.
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Antioxidant and Mineral Composition of Three Wild Leafy Species: A Comparison Between Microgreens and Baby Greens: Wild plants may play an important role in human nutrition and health and, among them, many are the leafy species. We hypothesized that the wild greens could be profitably grown as microgreens and baby greens, specialty products whose market is increasing. We compared three wild leafy species (Sanguisorba minor Scop., Sinapis arvensis L., and Taraxacum officinale Weber ex F. H. Wigg.) harvested at the microgreen and baby green stages. Seedlings were grown hydroponically in a half-strength Hoagland nutrient solution under controlled climatic conditions. At harvest, the yield was assessed, and chlorophylls, carotenoids, anthocyanins, phenolic index, nitrate, and mineral elements were measured in the two types of product. The potential contribution to human mineral intake was calculated, and the possible risk due to the presence of metals potentially detrimental for health was estimated. Results showed that micro/baby greens of the studied wild plants achieved competitive yields and could contribute to the dietary intake of macroelements, microelements, and non-nutrient bioactive compounds. On the other hand, the wild greens showed high amounts of nitrate and traces of some metals potentially detrimental for health, suggesting the need for caution in the use of wild species for producing microgreens and baby leaves.
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Transcriptional changes in prostate of men on active surveillance after a 12-mo glucoraphanin-rich broccoli intervention—results from the Effect of Sulforaphane on prostate CAncer PrEvention (ESCAPE) randomized controlled trial: Epidemiological evidence suggests that consumption of cruciferous vegetables is associated with reduced risk of prostate cancer progression, largely attributed to the biological activity of glucosinolate degradation products, such as sulforaphane derived from glucoraphanin. Because there are few therapeutic interventions for men on active surveillance for prostate cancer to reduce the risk of cancer progression, dietary approaches are an appealing option for patients.
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Antioxidant properties and sensory evaluation of microgreens from commercial and local farms: Microgreens are young and tender vegetables or herbs that provide attractive color, flavor, and nutrition. The purpose of this study was to evaluate the nutritional and sensory qualities of broccoli microgreens grown by different methods (hydroponically vs. soil grown) and from different sources (commercial vs. local farm). No significant difference in total phenolic concentration and antioxidant capacity was found in all broccoli microgreens, but a significantly higher chlorophyll concentration was found in farm microgreens than the commercial ones. Moreover, the soil-grown farm microgreens possessed a significantly higher vitamin C concentration than hydroponically-grown farm sample and commercial sample. Participants in the sensory study favored farm samples regardless of growing method, and their overall liking was significantly correlated with taste of the microgreens. In addition, six other microgreens from the local farm were analyzed for their nutritional quality. These conclusions suggested a potential for consumers to still benefit nutritionally by purchasing commercial microgreens at a lower cost; however, it may be worthwhile for consumers to purchase microgreens from local farms for a better sensory experience
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Current Review of the Modulatory Effects of LED Lights on Photosynthesis of Secondary Metabolites and Future Perspectives of Microgreen Vegetables: Light-emitting diode (LED) lights have recently been applied in controlled environment agriculture toward growing vegetables of various assortments, including microgreens. Spectral qualities of LED light on photosynthesis in microgreens are currently being studied for their ease of spectral optimization and high photosynthetic efficiency. This review aims to summarize the most recent discoveries and advances in specific phytochemical biosyntheses modulated by LED and other conventional lighting, to identify research gaps, and to provide future perspectives in this emerging multidisciplinary field of research and development. Specific emphasis was made on the effect of light spectral qualities on the biosynthesis of phenolics, carotenoids, and glucosinolates, as these phytochemicals are known for their antioxidant, anti-inflammatory effects, and many health benefits. Future perspectives on enhancing biosynthesis of these bioactives using the rapidly progressing LED light technology are further discussed.
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Rapid multi-element characterization of microgreens via total-reflection X-ray fluorescence (TXRF) spectrometry: Microgreens are an emerging class of vegetables, which have become increasingly important in the agri-food market in recent years, and contain a number of macro- and micro-nutrients. This paper presents a rapid method for the elemental analysis of microgreens based on total reflection X-ray fluorescence (TXRF) spectroscopy, without preliminary sample digestion. The following elements were detected and quantified simultaneously for six microgreen genotypes, belonging to Asteraceae and Brassicaceae: P, S, K, Ca, Cl, Mn, Fe, Ni, Cu, Zn, Br, Rb, Sr. The limit of detection (LOD) varied depending on the element and ranged between 0.1 mg kg−1 for Sr and 42 mg kg−1 for P. The method was validated using certified standards, and results compared with those obtained using a conventional ICP-AES method requiring sample digestion. The paper also presents the advantages and disadvantages of the two techniques.
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Microgreens, a new specialty crop: Frequently called “vegetable confetti,” microgreens are young, tender greens that are used to enhance the color, texture, or flavor of salads, or to garnish a wide variety of main dishes (Figures 1 and 2). Harvested at the first true leaf stage and sold with the stem, cotyledons (seed leaves), and first true leaves attached, they are among a variety of novel salad greens available on the market that are typically distinguished categorically by their size and age. Sprouts, microgreens, and baby greens are simply those greens harvested and consumed in an immature state. Based on size or age of salad crop categories, sprouts are the youngest and smallest, microgreens are slightly larger and older (usually 2 in. tall), and baby greens are the oldest and largest (usually 3–4 in. tall).
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Microgreens: Consumer sensory perception and acceptance of an emerging functional food crop: Microgreens are an emerging functional food crop with promise for sustainably diversifying global food systems, facilitating adaptations to urbanization and global climate change, and promoting human health. Previous work suggests microgreens have high nutritional quality, low environmental impacts, and broad consumer acceptance. For better reception into the global food system and increased per capita consumption, research is needed to elucidate consumer acceptance of various microgreens species, including factors contributing to their acceptance or lack thereof. Using a consumer panel (n = 99), this study evaluated consumer sensory perception and acceptability of six microgreens species (arugula, broccoli, bull's blood beet, red cabbage, red garnet amaranth, and tendril pea), and potential drivers and barriers to consumer acceptance. All microgreens species received high mean liking scores for acceptability by consumers (means ranged from highly acceptable to slightly acceptable), with more distinct differences across microgreens species for flavor and overall acceptability, which appeared to be driven by specific sensory properties. Data from principal component analysis demonstrated that high acceptability scores were associated with higher intent to purchase microgreens and negatively associated with food neophobia. Participants indicated that factors such as knowledge and familiarity of microgreens, cost, access/availability, freshness/shelf life, among other factors, influence their intention to purchase microgreens. These findings suggest that further integration of microgreens into the global food system will be met with high consumer acceptability, but needs to be aligned with enhanced consumer education regarding microgreens, as well as considerations of cost, availability/access, and freshness/shelf life.
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Variation in Macronutrient Content, Phytochemical Constitution and In Vitro Antioxidant Capacity of Green and Red Butterhead Lettuce Dictated by Different Developmental Stages of Harvest Maturity: Rising life expectancy and the demanding modern lifestyle drive the growing appeal of healthy and balanced diets centered on vegetable and fruit consumption. Functional, phytonutrient-packed and principally raw food is in high demand. Microgreens constitute such a novel functional food that combines a high sensory and bioactive value, which invites comparison to their mature-leaf counterparts. For this purpose, a controlled environment chamber experiment was carried out to compare the mineral, phytochemical and antioxidant capacity attributes of two-pigmented Lactuca sativa L. var. capitata cultivars (green and red Salanova®) harvested at the microgreens and the mature-leaf stage. Macronutrients were assessed through ion chromatography, while carotenoids and polyphenols were assessed and quantified through HPLC-DAD and UHPLC-Q-Orbitrap HRMS, respectively. Calcium and magnesium were higher in microgreens irrespective of the cultivar; conversely, phosphorous, potassium and nitrate where higher in mature leaves. All pigments including chlorophyll, lutein and β-carotene augmented at advanced maturity stage and were more concentrated in the red pigmented cultivar at both stages. Total polyphenols accumulated more densely in red Salanova, particularly in the microgreens stage; whereas, in green Salanova, the accumulation was significant but less pronounced in the mcirogreens stage. Chlorogenic acid, quercetin malonyl glucoside, rutin and coumaroyl quinic acid were the most concentrated phenolic acids in microgreens, while feruloyl tartaric acid was predominant in mature leaves. Finally, when a high carotenoids content is sought, mature lettuce leaves should be the prime culinary choice, whereas high polyphenolic content is dictated by both the cultivar and the harvest stage, with red Salanova microgreens being the most nutrient-packed choice.
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Bioactive Compounds and Bioactivities of Brassica oleracea L. var. Italica Sprouts and Microgreens: An Updated Overview from a Nutraceutical Perspective: Sprouts and microgreens, the edible seedlings of vegetables and herbs, have received increasing attention in recent years and are considered as functional foods or superfoods owing to their valuable health-promoting properties. In particular, the seedlings of broccoli (Brassica oleracea L. var. Italica) have been highly prized for their substantial amount of bioactive constituents, including glucosinolates, phenolic compounds, vitamins, and essential minerals. These secondary metabolites are positively associated with potential health benefits. Numerous in vitro and in vivo studies demonstrated that broccoli seedlings possess various biological properties, including antioxidant, anticancer, anticancer, antimicrobial, anti-inflammatory, anti-obesity and antidiabetic activities. The present review summarizes the updated knowledge about bioactive compounds and bioactivities of these broccoli products and discusses the relevant mechanisms of action. This review will serve as a potential reference for food selections of consumers and applications in functional food and nutraceutical industries.
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Current Knowledge on Selenium Biofortification to Improve the Nutraceutical Profile of Food: A Comprehensive Review: Selenium (Se) is an important micronutrient for living organisms, since it is involved in several physiological and metabolic processes. Se intake in humans is often low and very seldom excessive, and its bioavailability depends also on its chemical form, with organic Se as the most available after ingestion. The main dietary source of Se for humans is represented by plants, since many species are able to metabolize and accumulate organic Se in edible parts to be consumed directly (leaves, flowers, fruits, seeds, and sprouts) or after processing (oil, wine, etc.). Countless studies have recently investigated the Se biofortification of plants to produce Se-enriched foods and elicit the production of secondary metabolites, which may benefit human health when incorporated into the diet. Moreover, feeding animals Se-rich diets may provide Se-enriched meat. This work reviews the most recent literature on the nutraceutical profile of Se-enriched foods from plant and animal sources.
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Red beet (Beta vulgaris) and amaranth (Amaranthus sp.) microgreens: Effect of storage and in vitro gastrointestinal digestion on the untargeted metabolomic profile: This study aimed to investigate the combined effect of storage at 4 °C (10-days) and in vitro gastrointestinal digestion on the phytochemical profile of red beet (Beta vulgaris) and amaranth (Amaranthus sp.) microgreens. The untargeted profiling based on UHPLC-QTOF metabolomics allowed annotating 316 compounds, comprising mainly polyphenols and lipids. An impact of storage on the total phenolic content (TPC) was observed, with a maximum increase at 10-days of storage for both red beet (+1.3-fold) and amaranth (+1.1-fold). On the other hand, in vitro digestion of both red beet and amaranth microgreens produced a significant increase in TPC (36–88%), CUPRAC (27–40%), DPPH (6–43%), and BC (41–57%) to reach the maximum at 10 days of storage. Tyrosinase inhibitory potential also decreased following digestion. The combination of biochemical changes occurring in microgreen immature plants (likely in response to the harvest stress) with changes during digestion, determined the actual functional value of microgreens.
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Phenolic Constitution, Phytochemical and Macronutrient Content in Three Species of Microgreens as Modulated by Natural Fiber and Synthetic Substrates: The present study examined the modulatory effects of natural fiber substrates (agave fiber, coconut fiber and peat moss) and synthetic alternatives (capillary mat and cellulose sponge) on the nutritive and phytochemical composition of select microgreens species (coriander, kohlrabi and pak choi) grown in a controlled environment. Polyphenols were analyzed by UHPLC-Q-Orbitrap-HRMS, major carotenoids by HPLC-DAD, and macro-minerals by ion chromatography. Microgreens grown on peat moss had outstanding fresh and dry yield but low dry matter content. Natural fiber substrates increased nitrate and overall macro-mineral concentrations in microgreens compared to synthetic substrates. The concentrations of chlorophylls, carotenoids and ascorbate were influenced primarily by species. On the contrary, variability in polyphenols content was wider between substrates than species. Out of twenty phenolic compounds identified, chlorogenic acid and quercetin-3-O-rutinoside were most abundant. Hydroxycinnamic acids and their derivatives accounted for 49.8% of mean phenolic content across species, flavonol glycosides for 48.4% and flavone glycosides for 1.8%. Peat moss provided optimal physicochemical conditions that enhanced microgreens growth rate and biomass production at the expense of phenolic content. In this respect, the application of controlled stress (eustress) on microgreens growing on peat moss warrants investigation as a means of enhancing phytochemical composition without substantial compromise in crop performance and production turnover. Finally, nitrate deprivation practices should be considered for microgreens grown on natural fiber substrates in order to minimize consumer exposure to nitrate.
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Setup of an Extraction Method for the Analysis of Carotenoids in Microgreens: Microgreens are gaining increasing interest as a potential functional food due to their relevant contents of micronutrients and bioactive compounds, including carotenoids. Nevertheless, the analysis of carotenoids is inherently difficult, due to their thermal and chemical susceptibility, as well as to their varying polarity. From this point of view, extraction is the most critical step, compared to chromatographic separation and detection. Thus, the reliability of data on carotenoids should be guaranteed by a constant focus on analytical issues, with appropriate adaptations to each sample matrix. In this research, a specific extraction procedure for the analysis of carotenoids in microgreens was developed. Solvent composition, extraction time, solvent/sample ratio, and repeated extractions were evaluated. The obtained protocol showed recovery of 97.2%, limits of quantitation of 5.2 μg·g−1 for lutein and 15.9 μg·g−1 for β-carotene, as well as intra-day mean repeatability of 5.7% and inter-day mean repeatability of 4.7%.
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Microgreen nutrition, food safety, and shelf life: Microgreens have gained increasing popularity as food ingredients in recent years because of their high nutritional value and diverse sensorial characteristics. Microgreens are edible seedlings including vegetables and herbs, which have been used, primarily in the restaurant industry, to embellish cuisine since 1996. The rapidly growing microgreen industry faces many challenges. Microgreens share many characteristics with sprouts, and while they have not been associated with any foodborne illness outbreaks, they have recently been the subject of seven recalls. Thus, the potential to carry foodborne pathogens is there, and steps can and should be taken during production to reduce the likelihood of such incidents. One major limitation to the growth of the microgreen industry is the rapid quality deterioration that occurs soon after harvest, which keeps prices high and restricts commerce to local sales. Once harvested, microgreens easily dehydrate, wilt, decay and rapidly lose certain nutrients. Research has explored preharvest and postharvest interventions, such as calcium treatments, modified atmopsphere packaging, temperature control, and light, to maintain quality, augment nutritional value, and extend shelf life. However, more work is needed to optimize both production and storage conditions to improve the safety, quality, and shelf life of microgreens, thereby expanding potential markets.
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Metabolomic analysis based on EESI-MS indicate blue LED light promotes aliphatic-glucosinolates biosynthesis in broccoli sprouts : These findings suggest that blue light improving the accumulation of secondary metabolites in broccoli sprouts, and the R5B5 treatment was most beneficial. Furthermore, we established EESI-MS method to simultaneous and rapid detection of secondary metabolites in broccoli sprouts, especially GLs. This study could provide a reference for selecting proper LED lighting conditions to produce broccoli sprouts with high content of bioactive components, and provides light regulation technology and theoretical basis for the industrialized production of sprouts.
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Antiproliferative Effect of Bioaccessible Fractions of Four Brassicaceae Microgreens on Human Colon Cancer Cells Linked to Their Phytochemical Composition: The antiproliferative effect of the bioaccessible fractions (BFs) of four hydroponic Brassicaceae microgreens (broccoli, kale, mustard and radish) was evaluated on colon cancer Caco-2 cells vs. normal colon CCD18-Co cells after 24 h treatment with BFs diluted 1:10 v/v in cell culture medium. Their bioactivity was compared with the digestion blank, while the colon cancer chemotherapeutic drug 5-fluorouracil was used as a positive control. Cell viability (mitochondrial enzyme activity assay (MTT test) and Trypan blue test) and mechanisms related to antiproliferative activity (cell cycle, apoptosis/necrosis, mitochondrial membrane potential, reactive oxygen species (ROS) production, Ca2+ and glutathione (GSH) intracellular content) were studied. All microgreen BFs increased ROS and decreased GSH, altering the redox status and causing mitochondrial membrane dissipation followed by a general cell cycle arrest in G2/M and apoptotic cell death via a Ca2+-independent mechanism. As a result, the antioxidant bioactive compounds present in these microgreen species reduced the proliferation of tumoral cells (10 to 12.8% -MTT or 20 to 41.9% -Trypan blue), showing lesser effects with broccoli microgreens, in line with their lower ascorbic acid content and total antioxidant capacity. Therefore, the daily intake of microgreens within a balanced diet could be a preventive nutritional strategy to reduce the burden of chronic degenerative diseases such as colon cancer.
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Sprouts vs. Microgreens as Novel Functional Foods: Variation of Nutritional and Phytochemical Profiles and Their In vitro Bioactive Properties: The aim of the study was to analyze potential health-promoting and nutritional components (polyphenols, L-ascorbic acid, carotenoids, chlorophylls, amino acids, organic acid, sugars, ash and pectins) of selected sprouts (radish, lentil, black medick, broccoli, sunflower, leek, beetroot, mung beans) and microgreens (kale, radish, beetroot, green peas, amaranth). Moreover, antioxidant capacity (2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), ferric reducing ability of plasma (FRAP), and oxygen radical absorbance capacity (ORAC)), in vitro anti-diabetic potential (inhibition of α-amylase and α-glucosidase), and anti-obesity (pancreatic lipase) and anti-cholinergic (acetylcholinesterase and butyrylcholinesterase) activity were evaluated. The results of this study show that sprouts are effective in antioxidant capacity as a result of a high content of polyphenols and L-ascorbic acid. Additionally, sprouts are better sources of amino acids, pectins and sugars than microgreens. Microgreens were characterized by high content of carotenoids and chlorophylls, and organic acid, without any sugars, exhibiting higher anti-diabetic and anti-cholinergic activity than sprouts. Some selected sprouts (broccoli, radish, lentil) and microgreens (radish, amaranths, kale) should be used daily as superfoods or functional food.
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Consumers’ acceptability and perceptions toward the consumption of hydroponically and soil grown broccoli microgreens: Microgreens are young and immature plants that are harvested after the development of the cotyledon leaves, or seed leaves. Because of their potent flavors and appealing sensory qualities, microgreens have gained popularity. This study aimed to investigate the differences in sensory attributes and consumers' perception between microgreens from commercial and local farms. Three samples of broccoli microgreens, including commercial hydroponically grown, local hydroponically grown, and local soil grown, respectively, were evaluated in this study. A total of 150 participants completed an acceptability study of broccoli microgreens and answered questions regarding perceived pricing, perceived benefits, and their willingness-to-buy. Overall, the participants rated the microgreens from the local farm as more favorable, regardless of growing method. The commercial microgreen sample from the local grocery had the lowest scores on all sensory attributes. The results also indicated that both sensory evaluation and consumers' perceived benefits present important roles in consumers' reference and consumption of microgreens. Pricing, however, did not show significant and direct effect on consumers' purchase intention. Consumers’ purchase intention was more affected by the sensory quality and perceived benefits than the pricing, in the case of broccoli microgreens. This study contributes to the literature of microgreens consumption and provides practical implications to help farmers and food retailers in the microgreens market.
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In Vitro Bioaccessibility and Bioavailability of Iron from Mature and Microgreen Fenugreek, Rocket and Broccoli: Iron deficiency is a global epidemic affecting a third of the world's population. Current efforts are focused on investigating sustainable ways to improve the bioavailability of iron in plant-based diets. Incorporating microgreens into the diet of at-risk groups in populations could be a useful tool in the management and prevention of iron deficiency. This study analysed and compared the mineral content and bioavailability of iron from microgreen and mature vegetables. The mineral content of rocket, broccoli and fenugreek microgreens and their mature counterparts was determined using microwave digestion and ICP-OES. Iron solubility and bioavailability from the vegetables were determined by a simulated gastrointestinal in vitro digestion and subsequent measurement of ferritin in Caco-2 cells as a surrogate marker of iron uptake. Iron contents of mature fenugreek and rocket were significantly higher than those of the microgreens. Mature fenugreek and broccoli showed significantly (p < 0.001) higher bioaccessibility and low-molecular-weight iron than found in the microgreens. Moreover, iron uptake by Caco-2 cells was significantly higher only from fenugreek microgreens than the mature vegetable. While all vegetables except broccoli enhanced FeSO4 uptake, the response to ferric ammonium citrate (FAC) was inhibitory apart from the mature rocket. Ascorbic acid significantly enhanced iron uptake from mature fenugreek and rocket. Microgreen fenugreek may be bred for a higher content of enhancers of iron availability as a strategy to improve iron nutrition in the populace.
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Yield and Quality Characteristics of Brassica Microgreens as Affected by the NH4:NO3 Molar Ratio and Strength of the Nutrient Solution: Microgreens are gaining more and more interest, but little information is available on the effects of the chemical composition of the nutrient solution on the microgreen yield. In this study, three Brassica genotypes (B. oleraceavar. italica, B. oleracea var. botrytis, and Brassica rapa L. subsp. sylvestris L. Janch. var. esculenta Hort) were fertigated with three modified strength Hoagland nutrient solutions (1/2, 1/4, and 1/8 strength) or with three modified half-strength Hoagland nutrient solutions with three different NH4:NO3 molar ratios (5:95, 15:85, and 25:75). Microgreen yields and content of inorganic ions, dietary fiber, proteins, α-tocopherol, and β-carotene were evaluated. Micro cauliflower showed the highest yield, as well as a higher content of mineral elements and α-tocopherol (10.4 mg 100 g−1 fresh weight (FW)) than other genotypes. The use of nutrient solution at half strength gave both a high yield (0.23 g cm−2) and a desirable seedling height. By changing the NH4:NO3 molar ratio in the nutrient solution, no differences were found on yield and growing parameters, although the highest β-carotene content (6.3 mg 100 g−1 FW) was found by using a NH4:NO3 molar ratio of 25:75. The lowest nitrate content (on average 6.8 g 100 g−1 dry weight) was found in micro broccoli and micro broccoli raab by using a nutrient solution with NH4:NO3 molar ratios of 25:75 and 5:95, respectively. Micro cauliflower fertigated with a NH4:NO3 molar ratio of 25:75 showed the highest dry matter (9.8 g 100 g−1 FW) and protein content (4.2 g 100 g−1 FW).
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Developing Production Guidelines for Baby Leaf Hemp (Cannabis sativa L.) as an Edible Salad Green: Cultivar, Sowing Density and Seed Size: Scientific literature is lacking on cultural practices of baby leaf hemp production even though hemp (Cannabis sativa L.) is a widely grown crop for fiber and grain. The objective of this study was to develop a standard protocol to optimize yield and quality of baby leaf hemp production: cultivar screening, sowing density and seed size. Fresh weight (FW) and germination percentage was significantly affected by cultivars. Cultivars ‘Picolo' and ‘X-59' had a greater FW mainly due to greater germination percentage. In the sowing density experiment, ‘Ferimon' and ‘Katani' were evaluated at five seed densities, 0.65, 1.2, 1.75, 2.3 and 2.85 seeds·cm −2 (42 to 182 seeds per cell). The FW and FW per plant (FWPP) had a positive quadratic response and negative quadratic response, respectively. Regarding seed size, cultivars ‘Anka,' ‘Ferimon' and ‘Picolo' had the largest percentage of seeds, 26% to 30%, within the medium width size between 3.18 and 3.37 mm. Using the largest sized seeds (3.77 mm) increased FW by 34%, 26% and 23% as compared to non-sorted ‘Anka', ‘Ferimon' and ‘Picolo' seeds, respectively. Overall, a greater understanding of cultivar selection, sowing density and seed-size distribution can promote greater yield and quality of baby leaf hemp as an edible salad green.
More for Hemp seeds procurement.
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2021, Studies on the Effects of Dietary Bioactive Components on Chronic Disease Prevention (due to complete 31/07/2021)
Studies on the Effects of Dietary Bioactive Components on Chronic Disease Prevention: To examine the effect of Brassaca microgreens on chronic disease prevention and to elucidate the mechanisms of action exerted by microgreens. We will test the hypothesis that microgreens (immature forms of plants such as cabbage and broccoli) protect against chronic diseases. Diet induced Obesity (DIO) mouse models and prostate cancer xenograft models will be used as chronic disease models. Animals will be fed a diet with or without microgreens. For a DOI model, the effect of microgreens on lipid/cholesterol metabolisms, inflammation-related markers will be assessed at protein and transcriptomic level. For cancer models, the effect of microgreens on tumor growth, cancer and inflammation-associated markers will be assessed at protein or transcriptomic levels. Objective 2. To assess the bioavailability of microgreen-derived bioactive compounds. Metabolomic analysis will be used to assess the bioavailability of microgreen bioactives using plasma and tissue samples from an in-vivo study in Objective 1. Objective 3. To examine the effects of microgreens on gut microbiome. Metagenomic analysis will be performed on cecal samples collected from Objective 1 to elucidate potential effects of microgreens on gut microbiota.
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Continuous LED Lighting Enhances Yield and Nutritional Value of Four Genotypes of Brassicaceae Microgreens:
The effect of continuous lighting (CL, 24 h) and light spectrum on growth and nutritional quality of arugula (Eruca sativa), broccoli (Brassica oleracea var. italic), mizuna (Brassica rapa. var. nipposinica), and radish (Raphanus sativus var. radicula) were investigated in growth chambers under light-emitting diode (LED) and fluorescent lighting. Microgreens were grown under four combinations of two photoperiods (16 h and 24 h) providing daily light integral (DLI) of 15.6 and 23.3 mol m-2 day-1, correspondingly) with two light spectra: LED lamps and fluorescent lamps (FLU). The results show that fresh and dry weights as well as leaf mass per area and robust index of harvested arugula, broccoli, mizuna, and radish seedlings were significantly higher under CL compared to 16 h photoperiod regardless of light quality. There were no visible signs of leaf photodamage. In all CL-treated plants higher chlorophyll a/b and carotenoid-to-chlorophyll ratios were observed in all plants except mizuna. CL treatment was beneficial for anthocyanin, flavonoid, and proline accumulation. Higher activities of antioxidant enzymes (catalase, superoxide dismutase, ascorbate peroxidase, and guaiacol peroxidase) were also observed in CL-treated plants. In most cases, the effects were more pronounced under LED lighting. These results indicate that plants under mild oxidative stress induced by CL accumulated more non-enzymatic antioxidants and increased the activities of antioxidant enzymes. This added nutritional value to microgreens that are used as functional foods providing health benefits. We suggest that for arugula, broccoli, mizuna, and radish, an LED CL production strategy is possible and can have economic and nutritional benefits. -
Light Intensity and Photoperiod Affect Growth and Nutritional Quality of Brassica Microgreens:
We explored the effects of different light intensities and photoperiods on the growth, nutritional quality and antioxidant properties of two Brassicaceae microgreens (cabbage Brassica oleracea L. and Chinese kale Brassica alboglabra Bailey). There were two experiments: (1) four photosynthetic photon flux densities (PPFD) of 30, 50, 70 or 90 μmoL·m-2·s-1 with red:blue:green = 1:1:1 light-emitting diodes (LEDs); (2) five photoperiods of 12, 14, 16, 18 or 20 h·d-1. With the increase of light intensity, the hypocotyl length of cabbage and Chinese kale microgreens shortened. PPFD of 90 μmol·m-2·s-1 was beneficial to improve the nutritional quality of cabbage microgreens, which had higher contents of chlorophyll, carotenoids, soluble sugar, soluble protein and vitamin C, as well as increased antioxidant capacity. The optimal PPFD for Chinese kale microgreens was 70 μmol·m-2·s-1. Increasing light intensity could increase the antioxidant capacity of cabbage and Chinese kale microgreens, while not significantly affecting glucosinolate (GS) content. The dry and fresh weight of cabbage and Chinese kale microgreens were maximized with a 14-h·d-1 photoperiod. The chlorophyll, carotenoid and soluble protein content in cabbage and Chinese kale microgreens were highest for a 16-h·d-1 photoperiod. The lowest total GS content was found in cabbage microgreens under a 12-h·d-1 photoperiod and in Chinese kale microgreens under 16-h·d-1 photoperiod. In conclusion, the photoperiod of 14~16 h·d-1, and 90 μmol·m-2·s-1 and 70 μmol·m-2·s-1 PPFD for cabbage and Chinese kale microgreens, respectively, were optimal for cultivation. -
Beyond vegetables: effects of indoor LED light on specialized metabolite biosynthesis in medicinal and aromatic plants, edible flowers, and microgreens:
Specialized metabolites from plants are important for human health due to their antioxidant properties. Light is one of the main factors modulating the biosynthesis of specialized metabolites, determining the cascade response activated by photoreceptors and the consequent modulation of expressed genes and biosynthetic pathways. Recent developments in light emitting diode (LED) technology have enabled improvements in artificial light applications for horticulture. In particular, the possibility to select specific spectral light compositions, intensities and photoperiods has been associated with altered metabolite content in a variety of crops. This review aims to analyze the effects of indoor LED lighting recipes and management on the specialized metabolite content in different groups of crop plants (namely medicinal and aromatic plants, microgreens and edible flowers), focusing on the literature from the last 5 years. The literature collection produced a total of 40 papers, which were analyzed according to the effects of artificial LED lighting on the content of anthocyanins, carotenoids, phenols, tocopherols, glycosides, and terpenes, and ranked on a scale of 1 to 3. Most studies applied a combination of red and blue light (22%) or monochromatic blue (23%), with a 16 h day-1 photoperiod (78%) and an intensity greater than 200 μmol m-2 s-1 (77%). These treatment features were often the most efficient in enhancing specialized metabolite content, although large variations in performance were observed, according to the species considered and the compound analyzed. The review aims to provide valuable indications for the definition of the most promising spectral components toward the achievement of nutrient-rich indoor-grown products. © 2021 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. -
The Nutritional Quality Potential of Microgreens, Baby Leaves, and Adult Lettuce: An Underexploited Nutraceutical Source:
Interest in the cultivation of lettuce landraces is increasing because native varieties, as high-quality products, are particularly attractive to consumers. Lettuce is a popular leafy vegetable worldwide, and interest in the consumption of first leaves (microgreens) and seedlings (baby leaves) has grown due to the general belief that young plants offer higher nutritional value. The content of some bioactive compounds and antioxidants (chlorophylls, carotenoids, anthocyanins, ascorbic acid, phenols, antioxidant activity) was monitored in six lettuce landraces and five commercial varieties, and compared across three development stages: microgreen, baby, and adult. Ascorbic acid and phenolic contents were 42% and 79% higher, respectively, in the early stages than in adult lettuces, and red-leaf varieties (CL4 and L11) stood out. This finding agrees with lettuce's marked antioxidant capacity and correlates with its pigment contents, especially anthocyanins. The nutritional value of adult lettuce is conditioned by its size, shape, and head structure as phytochemical concentrations are regulated by light. The low content of ascorbic acid, phenolics, and anthocyanins in crisphead lettuce (CL5) is a clear example (49, 67%, and 27% lower, respectively, than the adult mean). Our results indicate the wide variability of lettuces' nutritional characteristics and emphasize that traditional varieties are a helpful source of agricultural biodiversity. -
Sprouts and Microgreens-Novel Food Sources for Healthy Diets:
With the growing interest of society in healthy eating, the interest in fresh, ready-to-eat, functional food, such as microscale vegetables (sprouted seeds and microgreens), has been on the rise in recent years globally. This review briefly describes the crops commonly used for microscale vegetable production, highlights Brassica vegetables because of their health-promoting secondary metabolites (polyphenols, glucosinolates), and looks at consumer acceptance of sprouts and microgreens. Apart from the main crops used for microscale vegetable production, landraces, wild food plants, and crops' wild relatives often have high phytonutrient density and exciting flavors and tastes, thus providing the scope to widen the range of crops and species used for this purpose. Moreover, the nutritional value and content of phytochemicals often vary with plant growth and development within the same crop. Sprouted seeds and microgreens are often more nutrient-dense than ungerminated seeds or mature vegetables. This review also describes the environmental and priming factors that may impact the nutritional value and content of phytochemicals of microscale vegetables. These factors include the growth environment, growing substrates, imposed environmental stresses, seed priming and biostimulants, biofortification, and the effect of light in controlled environments. This review also touches on microgreen market trends. Due to their short growth cycle, nutrient-dense sprouts and microgreens can be produced with minimal input; without pesticides, they can even be home-grown and harvested as needed, hence having low environmental impacts and a broad acceptance among health-conscious consumers. -
Assessment of Antioxidant and Anticancer Activities of Microgreen Alga Chlorella vulgaris and Its Blend with Different Vitamins:
There is a very vital antioxidant extracted from microgreen alga. Chlorella vulgaris has major advantages and requires high yield worldwide. Some microalgae require vitamins for their growth promotion. This study was held to determine the impact of different vitamins including Thiamine (B1), Riboflavin (B2), Pyridoxine (B6), and Ascorbic acid (c) at concentrations of 0.02, 0.04, 0.06, and 0.08 mg/L of each. Each vitamin was added to the BG11 growth medium to determine the effect on growth, total carbohydrate, total protein, pigments content, antioxidant activities of Chlorella vulgaris. Moreover, antitumor effects of methanol extract of C. vulgaris without and with the supplement of thiamine against Human prostate cancer (PC-3), Hepatocellular carcinoma (HEPG-2), Colorectal carcinoma (HCT-116) and Epitheliod Carcinoma (Hela) was estimated in vitro. C. vulgaris supplemented with various vitamins showed a significant increase in biomass, pigment content, total protein, and total carbohydrates in comparison to the control. Thiamine was the best vitamin influencing as an antioxidant. C. vulgaris supplemented with thiamine had high antitumor effects in vitro. So, it's necessary to add vitamins to BG11 media for enhancement of the growth and metabolites. -
System design and production practices of aquaponic stakeholders:
Aquaponics is an agricultural practice incorporating aquaculture and hydroponic principles. This study assesses the current system design and production practices of the aquaponic industry, compares these metrics by stakeholder group, identifies trends, and provides recommendations for future development. An electronic survey of aquaponic stakeholders was conducted from December 2019 to June 2020 targeting hobbyists, producers, and educators from various aquaponic-focused professional associations, email and social media groups. Of 378 total responses, 84% came from the United States and were clustered in plant hardiness zones five to nine. Aquaponic systems were commonly homemade/do-it-yourself (DIY), many of which incorporated commercially available (turn-key) technology. Most growers used coupled systems that integrated recirculating aquaculture systems and either deep-water culture (DWC) or media bed hydroponic units. Common plant lighting sources were sunlight and light emitting diode (LED). Water sources were typically municipal or wells. Personal labor input was typically less than 20 hrs/wk. Funding sources were primarily personal funds, followed by government grants, and private investor funds. System sizes varied greatly, but the median area was 50 to 500 ft2 for hobbyists and educators and 500 to 3,000 ft2 for producers. Respondents commonly sold vegetable produce, training and education, food fish, and microgreens. Tilapia and ornamental fish were commonly grown, with 16 other species reported. Common crops were lettuce, leafy greens, basil, tomatoes, peppers, and herbs with many additional lesser-grown crops reported, including cannabis. Overall, the industry still growing, with a large portion of stakeholders having less than two years of experience. However, veteran growers have remained in operation, particularly in the producer and educator groups. The survey results suggest a shift away from outdoor systems, media beds, tomatoes, ornamental fish, and perch production, and a shift toward decoupled systems, DWC, drip irrigation, and wicking beds, larger system area, leafy greens, and trout/salmon production compared to previous industry surveys. The reduced diversity of plant species grown suggest some level of crop standardization. Commercial producers tended to sell more types of products than other stakeholders, suggesting that diversification of offerings may be key to profitability. The combined production area specified by respondents indicates the industry has grown substantially in recent years. Finally, the presence of bank loan-funded operations suggests increased knowledge and comfort with aquaponics among lenders.
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Vegetable microgreens: The gleam of next generation super foods, their genetic enhancement, health benefits and processing approaches:
Considering the well-being cognizance of masses, the microgreens have emerged as the potential therapeutic functional foods for improving the overall health by dietary supplementation. Microgreens have delicate texture, distinctive flavors and exceptional volume of various nutrients accounting for higher neutraceutical benefits compared to their mature counterparts. Mounting interest in microgreens owes not only to their nutritional significance but also to their fascinating organoleptic traits. Many factors like rapid shrinkage of the land resources, lifestyle modification, healthy diet habits, the functional importance of food etc. cumulatively have resulted in increased interest in the microscale production of vegetables for the ready-to-eat market. Augmenting the production of secondary metabolites could provide more nutritional benefits, sensory attributes, and resistance to pests while, sharing many characteristics with sprouts, they are not associated with any foodborne illness. Their production by manipulation of agronomic practices like seeds, growing media, and light quality and biofortification with nutrients may result in nutrient-rich produce. These high-value crops typically characterized by short postharvest life and several pre a-harvest treatments can effectively maintain the shelf life of microgreens. Further, several genetic improvement tools can enhance the availability of bioactive compounds with minimum antinutritional factors. In this review, the comparative overview of the nutritional significance of microgreens with sprouts and their mature counterparts has been discussed. Further, the advances or manipulations in production technologies, the involvement of breeding programmes, and efficient post-harvest technologies to promote cost-effective production and future strategies for maintaining the shelf life and quality of microgreens have been argued. -
Trial Protocol for Evaluating Platforms for Growing Microgreens in Hydroponic Conditions:
The hydroponic production of microgreens has potential to develop, at both an industrial, and a family level, due to the improved production platforms. The literature review found numerous studies which recommend procedures, parameters and best intervals for the development of microgreens. This paper aims to develop, based on the review of the literature, a set of procedures and parameters, included in a test protocol, for hydroponically cultivated microgreens. Procedures and parameters proposed to be included in the trial protocol for evaluating platforms for growing microgreens in hydroponic conditions are: (1) different determinations: in controlled settings (setting the optimal ranges) and in operational environments settings (weather conditions in the area/testing period); (2) procedures and parameters related to microgreen growth (obtaining the microgreens seedling, determining microgreen germination, measurements on the morphology of plants, microgreens harvesting); (3) microgreens production and quality (fresh biomass yield, dry matter content, water use efficiency, bioactive compound analysis, statistical analysis). Procedures and parameters proposed in the protocol will provide us with the evaluation information of the hydroponic platforms to ensure: number of growing days to reach desired size; yield per area, crop health, and secondary metabolite accumulation.
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Microbial Community Analysis and Food Safety Practice Survey-Based Hazard Identification and Risk Assessment for Controlled Environment Hydroponic/Aquaponic Farming Systems:
Hydroponic and aquaponic farming is becoming increasingly popular as a solution to address global food security. Plants in hydroponic systems are grown hydroponically under controlled environments and are considered to have fewer food safety concerns than traditional field farming. However, hydroponics and aquaponics might have very different sources of microbial food safety risks that remain under-examined. In this study, we investigated the microbiomes, microbial hazards, and potential bacterial transmission routes inside two commercial hydroponic and aquaponic farming systems using 16S-ITS-23S rRNA sequencing and a hydroponic food safety practice survey. The hydroponic farming system microbiome was analyzed from the fresh produce, nutrient solution, tools, and farmworkers. Proteobacteria, Actinobacteria, Cyanobacteria, Bacteroidetes, and Firmicutes were the main components of hydroponic/aquaponic farming systems, with Pseudomonas being the most abundant genus in fresh produce samples. We further identified the presence of multiple spoilage bacteria and potential human, plant, and fish pathogens at the subspecies level. Spoilage Pseudomonas spp. and spoilage Clostridium spp. were abundant in the hydroponic microgreen farm and aquaponic lettuce farm, respectively. Moreover, we demonstrated the mapping of Escherichia coli 16s-ITS-23s rRNA sequence reads (∼2,500 bp) to small or large subunit rRNA databases and whole-genome databases to confirm pathogenicity and showed the potential of using 16s-ITS-23s rRNA sequencing for pathogen identification. With the SourceTracker and overlapping amplicon sequence variants, we predicted the bidirectional transmission route between plants and the surrounding environment and constructed the bacteria transmission map, which can be implemented in future food safety risk control plans. -
Yield optimization, microbial load analysis, and sensory evaluation of mungbean (Vigna radiata L.), lentil (Lens culinaris subsp. culinaris), and Indian mustard (Brassica juncea L.) microgreens grown under greenhouse conditions:
Microgreens have been used for raw consumption and are generally viewed as healthy food. This study aimed to optimize the yield parameters, shelf life, sensory evaluation and characterization of total aerobic bacteria (TAB), yeast and mold (Y&M), Escherichia coli, Salmonella spp., and Listeria spp. incidence in mungbean (Vigna radiata (L.) Wilczek), lentil (Lens culinaris Medikus subsp. culinaris), and Indian mustard (Brassica juncea (L.) Czern & Coss.) microgreens. In mungbean and lentil, seeding-density of three seed/cm2, while in Indian mustard, eight seed/cm2 were recorded as optimum. The optimal time to harvest mungbean, Indian mustard, and lentil microgreens were found as 7th, 8th, and 9th day after sowing, respectively. Interestingly, seed size was found highly correlated with the overall yield in both mungbeans (r2 = .73) and lentils (r2 = .78), whereas no such relationship has been recorded for Indian mustard microgreens. The target pathogenic bacteria such as Salmonella spp. and Listeria spp. were not detected; while TAB, Y&M, Shigella spp., and E. coli were recorded well within the limit to cause any human illness in the studied microgreens. Washing with double distilled water for two minutes has shown some reduction in the overall microbial load of these microgreens. The results provided evidence that microgreens if grown and stored properly, are generally safe for human consumption. This is the first study from India on the safety of mungbean, lentils, and Indian mustard microgreens. -
This study aims to explore the hypoglycemic effect of lyophilized broccoli microgreens on type 2 diabetes (T2D) in mice. The experiment lasted 18 weeks, including 1 week of adaptation (normal diet) and 17-week experimental period (high-fat diet). After ingestion of broccoli microgreens, the body weight and glucose homeostasis were improved. Meanwhile, the blood lipid status, antioxidant indexes, and inflammatory factors level were improved. Moreover, the insulin resistance and the pathological changes in mice organs were reversed. In addition, the composition of gut microbiota and the production of propionic acid in intestinal content were improved. Our experiment proved that broccoli microgreens have the ability to regulate T2D and improve symptoms of mice T2D induced by high-fat diet and streptozotocin (STZ). PRACTICAL APPLICATIONS: For years, the functionality of broccoli microgreens has attracted much attention. This article will prove the therapeutic effect of broccoli microgreens on T2D and explain its principle of action in the management of T2D.
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Cold plasma effects on the nutrients and microbiological quality of sprouts:
Sprouts have been more and more popular among people all over the world due to their health benefits and good taste. Cold plasma (CP) is a promising and efficient nonthermal technology that has been applied to various aspects, including seed germination, plant growth, the synthesis of secondary metabolites. This review aims to represent the current knowledge status and future insights of CP on germination, nutritional quality and microbial inactivation of sprouts, and influencing mechanism was also discussed. CP under favorable conditions can promote the growth of sprouts, thus increase the yield of sprouts and microgreens. Numerous studies suggest that CP can promote the accumulation of bioactive compounds in sprouts, and subsequently enhance biological activities and so on the antioxidant capacity and antiproliferative effect. CP is an effective method for the inactivation of microorganisms on seeds and sprouts by reactive species. Therefore, CP is a promising technology for the sustainable development of sprouts industry.
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Microgreens represent a fast growing segment of the edible greens industry. They are prized for their colour, texture, and flavour. Compared to their mature counterparts, microgreens have much higher antioxidant and nutrient content categorizing them as a functional food. However, current production practices in plant factories with artificial light are energy intensive. Specifically, the lack of sunlight within the indoor structure means all of the light must be provided via energy consuming light fixtures, which is energy intensive and costly. Plant growth is usually increased with the total amount of light provided to the plants - daily light integral (DLI). Long photoperiods of low intensity lighting (greater than 18h) providing the desired/target DLI can reduce the capital costs for light fixtures and electricity costs. This is achieved by moving the electricity use from peak daytime hours (high price) to off-peak hours (low price) during the night in regions with time-based pricing scheme and lowering the electricity use for air conditioning, if plant growth is not compromised. However, lighting with photoperiods longer than tolerance thresholds (species/cultivar specific) usually leads to plant stress/damage. Therefore, we investigated the effects of continuous 24h white light (CL) at two DLIs (~14 and 21 mol m-2 d-1) on plant growth, yield, and antioxidant content on 4 types of microgreens - amaranth, collard greens, green basil, and purple basil to see if it compromises microgreen production. It was found that amaranth and green basil had larger fresh biomass when grown under CL compared to 16h when the DLIs were the same. In addition, purple basil had higher biomass at higher DLI, but was unaffected by photoperiods. Plants grown under the CL treatments had higher energy-use-efficiencies for lighting (10-42%) than plants grown under the 16h photoperiods at the same DLI. Notably, the electricity cost per unit of fresh biomass ($ g-1) was reduced (8-38%) in all microgreens studied when plants were grown under CL lighting at the same DLIs. Amaranth and collard greens also had higher antioxidant content. Taken together, growing microgreens under CL can reduce electricity costs and increase yield while maintaining or improving nutritional content.
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Hordeum vulgare L. microgreen mitigates reproductive dysfunction and oxidative stress in streptozotocin-induced diabetes and aflatoxicosis in male rats:
Diabetes mellitus type 2 (DM) is a common chronic disease worldwide, which may be due to increased environmental pollution. Aflatoxin B1 is a likely inevitable contaminant in food and dairy products. Both DM and aflatoxicosis exert a deleterious effect on reproduction urging the exploration of various functional food for protection. This study investigated the effect of barley microgreen (BM) on reproductive disorders caused by DM with or without aflatoxicosis in male rats. Rats were divided into eight groups; G1 control, G2 barley, G3 aflatoxin, G4 aflatoxin-barley, G5 streptozotocin (STZ), G6 STZ-barley, G7 STZ-aflatoxin, and G8 STZ-aflatoxin-barley. BM chemical composition revealed elevated calcium, iron, phosphorus, and vitamin A compared with barely seeds. Complete blood picture, lipid profile, serum oxidative stress parameters, relative testicular weight, sperm analysis, chromosomal aberration, and testis histopathology were performed. The lipid profile was altered significantly in G7. Oxidative stress was increased in G3, G5, and G7, whereas it was decreased in BM-treated groups. Sperm counts were reduced significantly in aflatoxin and/or STZ groups but increased significantly in BM-treated groups. Sperm morphological abnormalities and chromosomal aberrations were decreased significantly in BM-treated groups compared with untreated groups. Testicular histopathology revealed moderate diffuse degeneration of seminiferous tubules in aflatoxin and/or STZ groups, which were alleviated in BM-treated groups. In conclusion, aflatoxin and STZ together caused severe reproductive disorder and oxidative stress more than aflatoxin or STZ alone. BM diet reduced significantly oxidative stress and reproductive disorder associated with DM and aflatoxicosis in rats. -
Hemp (Cannabis sativa L.) is a multi-functional crop cultivated for fiber, seeds, or phytochemical extraction. Once a major industrial crop in several agro-environments, its cultivation strongly declined in developed countries since World War II. Exploiting hemp vegetative tissue as innovative food has remained largely unexplored. The current work examined the potential production of hemp microgreens. Six cultivars were assessed for yield and composition of organic acids, amino acids, polyphenols and phytocannabinoids, through IC, FLD-HPLC and UHPLC-HRMS, respectively. Bioactive composition was strongly related to the hemp variety. 'Silvana' demonstrated the highest total content of amino acids and essential amino acids, high concentrations of cannflavin A and B, and moderate levels of cannabidiol and cannabigerol. 'Finola' distinguished by the highest concentration of cannflavins and total polyphenols, and the lowest levels of Δ9-THC. Regardless of varietal differences, hemp microgreens proved widely safe in terms of Δ9-THC content.
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Broccoli (Brassica oleracea L. Var. italica) microgreens are rich in various nutrients, especially sulforaphane. NaCl application is an effective method to reduce nitrate content, and to improve sulforaphane content; however, NaCl application is associated with a risk in productivity reduction. Ca application is a well-known approach to cope with salt stress. Thus, we hypothesized that adding CaSO4 may mitigate the adverse effects of NaCl stress, and enhance the quality of broccoli microgreens. In this study, we conducted an experiment to investigate the effects of a combined treatment of NaCl and CaSO4 on the fresh yield, glucosinolates (GS), sulforaphane, nitrate, and mineral element contents of broccoli microgreens. The results showed that the incorporation of CaSO4 into NaCl solution unexpectedly increased the yield of the leaf area. Moreover, the addition of CaSO4 ameliorated the decline in GS under NaCl stress, and induced the accumulation of Ca and S. The nitrate content decreased more than three times, and sulforaphane content also decreased in the combined treatment of NaCl and CaSO4. This study proposes that the incorporation of CaSO4 into NaCl solution increases the yield, and alleviates the unfavorable effects induced by NaCl stress on the quality of broccoli microgreens. This study provides a novel approach for microgreens production.
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Tartary buckwheat microgreens (TBM) are popular worldwide products but display an extremely short shelf life. Thus, the effects of storage temperature, packaging material, and wash treatment on the quality and shelf life were analyzed. Headspace composition, weight loss, electrolyte leakage, microbial population and sensory quality were investigated during storage. Results showed that shelf life and quality of TBM decreased with the increment of storage temperature when stored at 5-25 °C. During 5 °C storage, LDPE bags were the best packaging materials for preserving the quality of LDPE, PE and HDPE bags. On the basis of 5 °C and LDPE packages, ClO2 + citric acid wash treatment could further inhibit quality deterioration and extend the shelf life. The results demonstrated bioactive constituents and antioxidant capacity were significantly affected by storage time. The study provides insights into developing optimal packaging and storage conditions for TBM.
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Microgreens Biometric and Fluorescence Response to Iron (Fe) Biofortification:
Microgreens are foods with high nutritional value, which can be further enhanced with biofortification. Crop biofortification involves increasing the accumulation of target nutrients in edible plant tissues through fertilization or other factors. The purpose of the present study was to evaluate the potential for biofortification of some vegetable microgreens through iron (Fe) enrichment. The effect of nutrient solution supplemented with iron chelate (1.5, 3.0 mg/L) on the plant's growth and mineral concentration of purple kohlrabi, radish, pea, and spinach microgreens was studied. Increasing the concentration of Fe in the medium increased the Fe content in the leaves of the species under study, except for radish. Significant interactions were observed between Fe and other microelements (Mn, Zn, and Cu) content in the shoots. With the increase in the intensity of supplementation with Fe, regardless of the species, the uptake of zinc and copper decreased. However, the species examined suggested that the response to Fe enrichment was species-specific. The application of Fe didn't influence plant height or fresh and dry weight. The chlorophyll content index (CCI) was different among species. With increasing fertilisation intensity, a reduction in CCI only in peas resulted. A higher dose of iron in the medium increased the fluorescence yield of spinach and pea microgreens. In conclusion, the tested species, especially spinach and pea, grown in soilless systems are good targets to produce high-quality Fe biofortified microgreens.
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Growth and Biochemical Composition of Microgreens Grown in Different Formulated Soilless Media:
Microgreens are immature young plants grown for their health benefits. A study was performed to evaluate the different mixed growing media on growth, chemical composition, and antioxidant activities of four microgreen species: namely, kale (Brassica oleracea L. var. acephala), Swiss chard (Beta vulgaris var. cicla), arugula (Eruca vesicaria ssp. sativa), and pak choi (Brassica rapa var. chinensis). The growing media were T1.1 (30% vermicast + 30% sawdust + 10% perlite + 30% PittMoss (PM)); T2.1 (30% vermicast + 20% sawdust + 20% perlite + 30% PM); PM was replaced with mushroom compost in the respective media to form T1.2 and T2.2. Positive control (PC) was Pro-mix BX™ potting medium alone. Root length was the highest in T1.1 while the shoot length, root volume, and yield were highest in T2.2. Chlorophyll and carotenoid contents of Swiss chard grown in T1.1 was the highest, followed by T2.2 and T1.1. Pak choi and kale had the highest sugar and protein contents in T2.2, respectively. Consistently, total phenolics and flavonoids of the microgreens were increased by 1.5-fold in T1.1 and T2.2 compared to PC. Antioxidant enzyme activities were increased in all the four microgreens grown in T1.1 and T2.2. Overall, T2.2 was the most effective growing media to increase microgreens plant growth, yield, and biochemical composition.
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Microgreens are edible young plants that have recently attracted interest because of their color and flavor diversity, phytonutrient abundance, short growth cycle, and minimal space and nutrient requirements. They can be cultivated in a variety of systems from simple home gardens to sophisticated vertical farms with automated irrigation, fertilizer delivery, and lighting controls. Microgreens have also attracted attention from space agencies hoping that their sensory qualities can contribute to the diet of astronauts in microgravity and their cultivation might help maintain crew physical and psychological health on long-duration spaceflight missions. However, many technical challenges and data gaps for growing microgreens both on and off Earth remain unaddressed. This review summarizes recent studies on multiple aspects of microgreens, including nutritional and socioeconomic benefits, cultivation systems, operative conditions, innovative treatments, autonomous facilities, and potential space applications. It also provides the authors' perspectives on the challenges to stimulating more extensive interdisciplinary research. Expected final online publication date for the Annual Review of Food Science and Technology, Volume 14 is March 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates
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Microgreens-A Comprehensive Review of Bioactive Molecules and Health Benefits:
Microgreens, a hypothesized term used for the emerging food product that is developed from various commercial food crops, such as vegetables, grains, and herbs, consist of developed cotyledons along with partially expanded true leaves. These immature plants are harvested between 7-21 days (depending on variety). They are treasured for their densely packed nutrients, concentrated flavors, immaculate and tender texture as well as for their vibrant colors. In recent years, microgreens are on demand from high-end restaurant chefs and nutritional researchers due to their potent flavors, appealing sensory qualities, functionality, abundance in vitamins, minerals, and other bioactive compounds, such as ascorbic acid, tocopherol, carotenoids, folate, tocotrienols, phylloquinones, anthocyanins, glucosinolates, etc. These qualities attracted research attention for use in the field of human health and nutrition. Increasing public concern regarding health has prompted humans to turn to microgreens which show potential in the prevention of malnutrition, inflammation, and other chronic ailments. This article focuses on the applications of microgreens in the prevention of the non-communicable diseases that prevails in the current generation, which emerged due to sedentary lifestyles, thus laying a theoretical foundation for the people creating awareness to switch to the recently introduced category of vegetable and providing great value for the development of health-promoting diets with microgreens.
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The Impact Of Social Media On Microgreens Product Knowledge And Purchase Intention: The purpose of this research is to find out the impact of social media Instagram on microgreens’ product knowledge and purchase intention by using several components of the AISAS model.Design/Methodology- Respondents in this study were 15 to 45 years old and were followers of Instagram accounts that disseminate knowledge and market microgreens’ products. This study uses a simple random sampling method. This study employs a variance-based structural equation modeling (SEM) analysis, that is partial least squares (PLS). The data from this research were analyzed using SmartPLS 3.0 software.Findings- The results revealed that social media significantly affected attention, Interest, and Search. Search has a significant and positive impact on increasing knowledge of microgreens products. Knowledge of microgreens products has a significant impact on purchase intentions of microgreens products. Originality- This research produces new findings regarding consumer behavior on microgreens and their influencing factors. Practical Implications- The results of this study can be used as a reference to find marketing methods and develop the most effective strategies to attract microgreens consumers.
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Microgreen Variety Impacts Leaf Surface Persistence of a Human Norovirus Surrogate:
Human norovirus (HuNoV) is a pathogenic agent that is frequently associated with foodborne disease outbreaks linked to fresh produce. Within microgreen production systems, understanding of virus transmission routes and persistence is limited. To investigate virus persistence on microgreen leaf surfaces, this study mimicked virus contaminations caused during microgreen handling by farm workers or during overhead irrigation with contaminated water. Specifically, approximately 5 log PFU of Tulane virus (TV)-a HuNoV surrogate-was inoculated on sunflower (SF) and pea shoot (PS) microgreen leaves at 7-day age. The virus reduction on SF was significantly higher than PS (p < 0.05). On day 10, total TV reduction for SF and PS were 3.70 ± 0.10 and 2.52 ± 0.30 log PFU/plant, respectively. Under the environmental scanning electron microscope (ESEM) observation, the leaf surfaces of SF were visually smoother than PS, while their specific effect on virus persistence were not further characterized. Overall, this study revealed that TV persistence on microgreen leaves was plant variety dependent. In addition, this study provided a preliminary estimation on the risk of HuNoV contamination in a microgreen production system which will aim the future development of prevention and control measures. -
Persistence and transfer of Tulane virus in a microgreen cultivation system:
Microgreens are niche salad greens which have increased in popularity among consumers in recent years. Due to similarities with sprouts and leafy greens-both attributed to numerous foodborne disease outbreaks-characterization of the food safety risks associated with microgreen production is warranted. The present study aimed to determine the fate and persistence of a human norovirus (HuNoV) surrogate, Tulane virus (TV), within a microgreen production system. Initially, the persistence of TV in two types of microgreen soil-free cultivation matrix (SFCM)-BioStrate® (biostrate) and peat-was determined. On day 0, water containing 7.6 log PFU of TV was applied to SFCM in growing trays, and the trays were maintained under microgreen growth conditions. TV persisted throughout the 10-day observation in biostrate and peat with overall reductions of 3.04 and 1.76 log plaque forming units (PFU) per tray, respectively. Subsequently, the transfer of TV to microgreen edible tissue was determined when planted on contaminated SFCM. Trays containing each type of SFCM were pre-inoculated with 7.6 log PFU of TV and equally divided into two areas. On day 0, sunflower (SF) or pea shoot (PS) seeds were planted on one-half of each tray, while the other half was left unplanted to serve as a control. The microgreens were harvested on day 10, and SFCM samples were collected from planted and unplanted areas of each tray. No TV were detected from the edible portion of either type of microgreen, yet TV were still present in the SFCM. TV concentrations were significantly lower in the root-containing planted area compared with the unplanted area for both biostrate (P = 0.0282) and peat (P = 0.0054). The mean differences of TV concentrations between unplanted and planted areas were 1.22 and 0.51 log PFU/g for biostrate and peat, respectively. In a subsequent investigation, TV transfer from day 7 inoculated SFCM to microgreens edible portion was not detected either. Overall, this study characterized the viral risk in a microgreen production system, which will help to understand the potential food safety risk related to HuNoV and to develop preventive measures.
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Effect of LED lights on the growth, nutritional quality and glucosinolate content of broccoli, cabbage and radish microgreens:
In this study, the effects of red (R), blue (B) and far-red (FR) LED lights and their combination (R + B, R + FR, B + FR, R + B + FR) together with white (W) LED light as control, on the growth, nutritional quality and the glucosinolates of brassica microgreens were determined. Fresh and dry weights were increased with W, R, R + FR lights in broccoli and cabbage and with the R + B + FR and B + FR in radish microgreens. Soluble solids content (SSC) (%) was highest with W, R and B lights in broccoli and cabbage. The highest titratable acidity (TA) (%) was determined with B, FR, R + FR, B + FR in broccoli and W, R + FR, R + B in cabbage. In radish, lower TA was determined. In broccoli microgreens, glucoraphanin content and total GSLs were increased with B light whereas in cabbage, the combination of R + B revealed the highest aliphatics, In radish, glucoraphenin was highest in B light and the glucoraphasatin in R, FR, R + FR and B lights. -
Effect of Storage Temperature on Storage Life and Sensory Attributes of Packaged Mustard Microgreens:
Short shelf life limits the commercial value of mustard microgreens. The present study was conducted to evaluate the effects of different storage temperatures on postharvest quality and sensory attributes of mustard microgreens to identify the optimum storage temperature. Mustard microgreens were stored at 5, 10, 15, 20, and 25 °C in 150 µm polyethylene bags. Samples were drawn at 0, 1, 2, 4, 7, 10, and 14 days and tested for changes in total chlorophyll content, tissue electrolyte leakage, weight loss, antioxidant activity, and sensory attributes. Storage temperature significantly (p < 0.05) affected the product quality, shelf life, and sensory quality. When stored at 5 °C, mustard microgreens showed no significant changes in antioxidant activity or tissue electrolyte leakage and minimal change in other parameters and maintained good overall sensory quality for 14 days. Samples stored at 10 and 15 °C retained good overall sensory quality for 4 and 2 days, respectively. When stored at 20 and 25 °C, microgreens deteriorated beyond consumption within one day. A storage temperature of 5 °C in 150 µm polythene bags can preserve high postharvest quality and sensory attributes for 14 days.
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