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Microgreens are young, tender greens that are used to enhance the color, texture, or flavor of salads and main dishes. They can be grown in small scales and indoors, making them widely adopted by controlled environment agriculture, an indoor farming practice is particularly important for feeding increasing urban populations. Besides, microgreens are attracting more consumers’ attention due to their high nutritional value and unique sensory characteristics. This review focuses on the nutrition quality, sensory evaluation, pre- and post-harvest interventions, and health benefits of microgreens. Microgreens are rich in vitamins (e.g., vitamin C), minerals (e.g., copper and zinc), and phytochemicals, including carotenoids and phenolic compounds, which act as antioxidants in human body. Pre-harvest interventions, such as illumination, salinity stress, nutrient fortification, and natural substrates, influence the photosynthetic and metabolic activities of microgreens and were shown to improve their nutritional quality, while the effects varied among species. After harvesting, packaging method and storage temperature can influence the nutrient retention in microgreens. Both in vitro and in vivo studies have shown that microgreens have anti-inflammatory, anti-cancer, anti-bacterial, and anti-hyperglycemia properties, making it a new functional food beneficial to human health. The sensory attributes and overall acceptability and liking of microgreens are primarily influenced by their phytochemical content. Microgreens are only getting popular during the last decades and research on microgreens is still at its early stage. More studies are warranted to optimize the pre- and post-harvest practices for nutrient enhancement and retention and to explore the potential health benefits of different microgreens for the prevention and treatment of chronic diseases.

In this study, thymol-loaded hydrophobically modified phytoglycogen/zein nanocomplexes with a particle size around 100 nm were developed for improving microbial safety of fresh produce. The antimicrobial activities, including the determination of minimum inhibitory and bactericidal concentration, growth kinetic curves, and inhibition zone of the nanocomplexes against foodborne pathogens (Listeria monocytogenes, Salmonella enteritidis, and Escherichia coli) were evaluated. The results showed that the antimicrobial activities of the nanocomplexes were significantly stronger than that of free thymol control (without encapsulation), and the antimicrobial efficacy remained unchanged after storage at 4 °C for 60 days. The morphological results from atomic force microscope revealed that small micellar blebs were formed at the surface of bacteria after treatment with nanocomplexes and the gradual disappearance of the cell boundary indicated the occurrence of cytolysis. The potential applications of this nanocomplex as disinfectant agent in wash water were evaluated on different types of fresh produce (lettuce, cantaloupe, and strawberries). Notably, the nanocomplexes also demonstrated efficacy in biofilm removal. Findings from this study clearly demonstrated that the thymol-loaded nanocomplexes hold promising potential for the disinfection of fresh produce to improve their microbial safety and quality.

Microgreen is a class of emerging fresh produce that are generally rich in vitamins, carotenoids, and other phytochemicals. However, their genetic diversity in phytonutrients has yet to be discovered. In this study, 30 varieties of microgreens in the Brassicaceae family were assayed for phytochemical concentrations and antioxidant capacity. Distinct genotypic variations were observed for ascorbic acid, α-tocopherol, phylloquinone, β-carotene, lutein/zeaxanthin, total glucosinolates, total phenolics as well as 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity. Results indicated that the Brassicaceae microgreens are good sources of antioxidant phytochemicals, although there are substantial variations within and between species. The nutrient data of Brassicaceae microgreens presented in this study provide valuable information to dieticians, nutrition policy makers, and health-conscious consumers, and growers in the selection of nutrient-dense vegetables.

β-Glucan in oat is widely considered as the main ingredient for the anti-hypercholesterol effects; however, phenolic compounds in oat are also regarded to possess potential activities against dyslipidemia. In order to understand the underlying mechanisms thoroughly, it is of great significance to evaluate and compare the hypolipidemic properties exerted by oat phenol-rich extract (PE) and β-glucan extract (GE) in hyperlipidemic ICR mice induced by high-fat diet. The study was conducted for 12 weeks. Both PE and GE showed a significant hypocholesterolemic action by reducing the concentration of serum total cholesterol (TC), low density lipoprotein cholesterol and hepatic TC. Only PE reduced the hepatic triacylglycerol (TG), inhibited hepatic 3-hydroxy-3-methylglutary CoA reductase activities and improved the hepatic antioxidant defense system. However, GE significantly increased fecal excretion of neutral cholesterol and bile acids. This study demonstrated that not only β-glucan but also oat phenolic acids contributed to a preventive effect on hyperlipidemia. Based on the cholesterol metabolism and antioxidant defense system, the effects of the two functional components of oat were exerted in different ways.

The mineral element composition was analyzed for 30 varieties of microgreens, representing 10 species within 6 genera of the Brassicaceae family. Brassicaceae microgreens were assayed for concentrations of macroelements, including calcium (Ca), magnesium (Mg), phosphorous (P), sodium (Na), potassium (K), and of microelements, including copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn). Determinations of mineral elements in microgreen samples were performed using an inductively coupled plasma optical emission spectrophotometer (ICP OES). Potassium was the most abundant macroelement ranging from 176 to 387 mg/100 g fresh weight (FW), followed by P (52–86 mg/100 g FW), Ca (28–66 mg/100 g FW), Mg (28–66 mg/100 g FW), and Na (19–68 mg/100 g FW). Among the microelements, Fe tended to be most abundant (0.47–0.84 mg/100 g FW), followed by Zn (0.22–0.51 mg/100 g FW), Mn (0.17–0.48 mg/100 g FW), and Cu (0.041–0.13 mg/100 g FW). Based upon the analysis of 30 varieties, the results demonstrate that microgreens are good sources of both macroelements (K and Ca) and microelements (Fe and Zn.). Consumption of microgreens could be a health-promoting strategy to meet dietary reference intake requirements for essential elements beneficial to human health.

Microgreens are an emerging food product with scarce information pertaining to their sensory and nutritional properties. In this study, six species of microgreens, including Dijon mustard (Brassica juncea L. Czern.), opal basil (Ocimum basilicum L.), bull’s blood beet (Beta vulgaris L.), red amaranth (Amaranthus tricolor L.), peppercress (Lepidium bonariense L.) and China rose radish (Raphanus sativus L.), were evaluated for their sensory attributes and chemical compositions. Results showed that bull’s blood beet had the highest rating on acceptability of flavor and overall eating quality while peppercress the lowest. Chemical compositions also differed significantly among the six species. China rose radish had the highest titratable acidity and total sugars, while red amaranth had the highest pH value and lowest total sugars. Regarding the phytonutrient concentrations, the highest concentrations of total ascorbic acid, phylloquinone, carotenoids, tocopherols, and total phenolics were found in China rose radish, opal basil, red amaranth, China rose radish, and opal basil, respectively. The relationships between sensory–sensory attributes and sensory–chemical compositions were further studied. It was found that overall eating quality of microgreens was best correlated with flavor score and microgreen’s pH value and total phenolic content were strongly correlated with flavor attributes, e.g., sourness, astringency, and bitterness. In general, despite the differences among individual microgreens, all of the microgreens evaluated in this study demonstrated “good” to “excellent” consumer acceptance and nutritional quality.

Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157:H7 by using peat moss-based soil-substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants (7 days postseeding) and in growth medium were examined. E. coli O157:H7 was shown to survive and proliferate significantly during microgreen growth in both production systems, with a higher level in the hydroponic production system. At the initial seed inoculation level of 3.7 log CFU/g, E. coli O157:H7 populations on the edible part of microgreen plants reached 2.3 and 2.1 log CFU/g (overhead irrigation and bottom irrigation, respectively) for microgreens from the soil-substitute production system and reached 5.7 log CFU/g for those hydroponically grown. At a higher initial inoculation of 5.6 log CFU/g seeds, the corresponding E. coli O157:H7 populations on the edible parts of microgreens grown in these production systems were 3.4, 3.6, and 5.3 log CFU/g, respectively. Examination of the spatial distribution of bacterial cells on different parts of microgreen plants showed that contaminated seeds led to systematic contamination of whole plants, including both edible and inedible parts, and seed coats remained the focal point of E. coli O157:H7 survival and growth throughout the period of microgreen production.

Both sprouts and microgreens are popular tender produce items, typically grown and harvested in indoor facilities which allow a higher degree of control compared to open field production. While sprouts, which have frequently been implicated in foodborne illness outbreaks, are the subject of numerous national and international standards for their production and distribution, there is a lack of data pertaining to the microbiological safety of microgreens. In this study, sprouts and microgreens were produced from radish seeds inoculated with Escherichia coli O157: H7 or O104: H4 and E. coli populations on the harvested products compared to assess the potentials of product contamination from contaminated seeds during sprouting and microgreen production. Both E. coli O157:H7 and O104:H4 grew rapidly during sprouting, reaching levels of 5.8–8.1 log cfu/g and 5.2–7.3 log cfu/g, respectively, depending on the initial inoculation levels of the seeds (1.5–4.6 log cfu/g and 0.8–4.3 log cfu/g on radish seeds, respectively). In comparison, E. coli O157:H7 and O104:H4 populations on harvested microgreens ranged from 0.8 to 4.5 log cfu/g and from 0.6 to 4.0 log cfu/g, respectively. Although harvested microgreens carried significantly less (P

Microgreens are new and emerging products, which are young seedlings of vegetables and herbs. A recent study showed that microgreens contain higher nutrients compared to their mature counterparts. However, they typically have a short shelf life (1–2 days) at ambient temperature. The objective of this study was to optimize postharvest handling conditions to reduce the quality loss and extend the shelf life of daikon radish (Raphanus sativus L. var. longipinnatus) microgreens. Storage temperature, packaging film, and wash treatment were investigated. Changes in headspace composition, quality index, chlorophyll concentration, tissue electrolyte leakage, and aerobic mesophilic bacteria (AMB) and yeast & mold (YM (2) film oxygen transmission rate (OTR) significantly (P

Buckwheat microgreens have short shelf life which limits their commercial use. The effects of storage temperature, modified atmosphere packaging (MAP), and wash conditions on quality and shelf life of buckwheat microgreens were assessed. Temperature significantly (P

Cardiovascular disease (CVD) is the leading cause of death in the United States, and hypercholesterolemia is a major risk factor. Population studies, as well as animal and intervention studies, support the consumption of a variety of vegetables as a means to reduce CVD risk through modulation of hypercholesterolemia. Microgreens of a variety of vegetables and herbs have been reported to be more nutrient dense compared to their mature counterparts. However, little is known about the effectiveness of microgreens in affecting lipid and cholesterol levels. The present study used a rodent diet-induced obesity (DIO) model to address this question. C57BL/6NCr mice (n = 60, male, 5 weeks old) were randomly assigned to six feeding groups: (1) low-fat diet; (2) high-fat diet; (3) low-fat diet + 1.09% red cabbage microgreens; (4) low-fat diet + 1.66% mature red cabbage; (5) high-fat diet + 1.09% red cabbage microgreens; (6) high-fat diet + 1.66% mature red cabbage. The animals were on their respective diets for 8 weeks. We found microgreen supplementation attenuated high-fat diet induced weight gain. Moreover, supplementation with microgreens significantly lowered circulating LDL levels in animals fed the high-fat diet and reduced hepatic cholesterol ester, triacylglycerol levels, and expression of inflammatory cytokines in the liver. These data suggest that microgreens can modulate weight gain and cholesterol metabolism and may protect against CVD by preventing hypercholesterolemia.

a b s t r a c t This study evaluated the effects of sodium chlorite (SC) alone and its sequential treatment with edible coatings on browning inhibition and quality maintenance of fresh-cut d'Anjou pears. Edible coatings were prepared from chitosan (CH) and its water-soluble derivative carboxymethyl chitosan (CMCH), separately. Pear wedges were immersed in SC solution, followed by coating with CH or CMCH solu- tions. The samples were packed in unsealed bags and stored at 4 ◦ C for subsequent color, firmness, and weight loss measurement. The effects of the SC and coating treatments on polyphenol oxidase (PPO) inhibition and microbial inactivation were also evaluated. Results indicated that SC exhibited significant (P < 0.05) inhibition of browning and PPO activity. The SC treatment was also strongly effective in inactivating Escherichia coli O157:H7 on pear slices. Coating SC-treated pear slices with CH adversely affected the quality of pear slices by accelerating the discoloration of cut surfaces and increasing the PPO activity. On the contrary, coating SC-treated samples with CMCH significantly prevented the browning reaction and inhibited PPO activity. In addition, SC and CH/CMCH coatings maintained tissue firmness and did not affect weight loss. Our study may provide a scientific basis for the use of SC + CMCH treatment as an alternative preservation treatment for fresh-cut fruits and vegetables.

The functional formula diet AHP, containing polysaccharides from Auricularia auricular, polyphenolic compounds from Hawthorn (Crataegus) and Pueraria radix, has been recently developed as a dietary intervention against dyslipidemia in our previous study. In the present study, its antioxidant activities and protective effects against proliferation of vascular smooth muscle cells (VSMCs) were investigated. AHP possessed the potent radical-scavenging effects against hydroxyl and superoxide radicals, and also the inhibitory effects against peroxidation of low density lipoprotein induced by Cu2+ in vitro. The protective effects of AHP against proliferation of VSMCs were evaluated through the methodology of serum pharmacology. The serum containing AHP significantly inhibited the proliferation of VSMCs induced by oxidized low density lipoprotein in a time- and dose-dependent manner, and also promoted the nitric oxide production of VSMCs. Our study indicated that this functional formula diet would be a potent alternative as a functional diet to prevent atherosclerosis at early stage.

The cholesterol-lowering properties of Auricularia auricula are commonly attributed to the presence of polysaccharides based on previous research. The present study was designed to investigate the effects of ethanol extract of A. auricula (AAE) on hypercholesterolemia in ICR mice. AAE contained more than 16% (g/g) polyphenolic compounds, excluding other interfering factors such as polysaccharides, water-soluble fibre and protein. Thirty-six mice were randomly assigned to three groups (n = 12). The experimental group was fed cholesterol-enriched diet (CED) with oral administration of AAE (150 mg/kg/d b.w.) for 8-week, normal control group and CED control group received either a regular diet (RD) or CED along with oral administration of equal volume distilled water. Serum lipid profiles and antioxidant status were measured in addition to fecal neutral cholesterol and bile acids. AAE showed a remarkable hypocholesterolemic effect, improving antioxidant status, decreasing the level of total cholesterol and atherosclerosis index, increasing the level of high-density lipoprotein cholesterol and fecal excretion of bile acids. No apparent effects on serum triglycerides, low-density lipoprotein cholesterol, fecal excretion of neutral cholesterol and feeding efficiency were observed among all groups. These results indicated that A. auricula functional components, which prevented hypercholesterolemia contained polyphenolic compounds, in addition to polysaccharides.

Radish (Raphanus sativus var. longipinnatus) microgreens were produced from seeds inoculated with Escherichia coli O157:H7 by using peat moss-based soil-substitute and hydroponic production systems. E. coli populations on the edible and inedible parts of harvested microgreen plants (7 days postseeding) and in growth medium were examined. E. coli O157:H7 was shown to survive and proliferate significantly during microgreen growth in both production systems, with a higher level in the hydroponic production system. At the initial seed inoculation level of 3.7 log CFU/g, E. coli O157:H7 populations on the edible part of microgreen plants reached 2.3 and 2.1 log CFU/g (overhead irrigation and bottom irrigation, respectively) for microgreens from the soil-substitute production system and reached 5.7 log CFU/g for those hydroponically grown. At a higher initial inoculation of 5.6 log CFU/g seeds, the corresponding E. coli O157:H7 populations on the edible parts of microgreens grown in these production systems were 3.4, 3.6, and 5.3 log CFU/g, respectively. Examination of the spatial distribution of bacterial cells on different parts of microgreen plants showed that contaminated seeds led to systematic contamination of whole plants, including both edible and inedible parts, and seed coats remained the focal point of E. coli O157:H7 survival and growth throughout the period of microgreen production.

Brassica vegetables are known to contain relatively high concentrations of bioactive compounds associated with human health. A comprehensive profiling of polyphenols from five Brassica species microgreens was conducted using ultra high-performance liquid chromatography photo diode array high-resolution multi-stage mass spectrometry (UHPLC-PDA-ESI/HRMSn). A total of 164 polyphenols including 30 anthocyanins, 105 flavonol glycosides, and 29 hydroxycinnamic acid and hydroxybenzoic acid derivatives were putatively identified.The putative identifications were based on UHPLC-HRMSn analysis using retention times, elution orders, UV/Vis spectra and high resolution mass spectra, in-house polyphenol database, and as well as literature comparisons. This study showed that these five Brassica species microgreens could be considered as good sources of food polyphenols.

Radish microgreens constitute a good source of bioactive compounds; however, they are very delicate and have a short shelf life. In this study, we investigated the impact of light exposure and modified atmosphere packaging on sensorial quality, bioactive compound concentrations and antioxidant capacity of radish microgreens during storage. Results showed that light exposure during storage increased the amount of ascorbic acid and had no effect on α-tocopherol or total phenolic concentrations. Dark storage resulted in higher hydroxyl radical scavenging capacity and carotenoid retention. No significant differences were found for relative 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging capacity between light and dark treatments. Radish microgreens in bags of 29.5 pmol s(-1) m(-2) Pa(-1) oxygen transmission rate (OTR) maintained better quality than those within laser microperforated bags. In conclusion, light exposure accelerated deterioration of radish microgreens, while dark storage maintained quality; and application of OTR bags was beneficial in extending shelf life.

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 to 147.0 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.

Polysaccharides from Auricularia auricula (AAP) extracted in hot water and precipitated by ethanol were chemically well defined, including 42.5% total carbohydrate, 19.6% uronic acids, 15.8% sulfate groups, 1.7% N, and 20.3% ash. Gas chromatography analysis demonstrated that the neutral sugars were mainly composed of rhamnose, xylose, and glucose and smaller amounts of mannose, galactose, and arabinose. The present study was designed to investigate the antioxidant capacity of AAP on blood lipid metabolism and lipoprotein lipase (LPL) activity in ICR mice fed cholesterol-enriched diet (CED) for the 1st time. Furthermore, the relationship between the atherosclerotic index (AI) and LPL activity to total antioxidant capacity (TAC) was studied. Thirty-six ICR mice were randomly assigned to 3 groups (n=12). The mice in control group (NG) received regular diet and the mice in model group (MG) received CED; these 2 groups were provided with distilled water by oral gavage. The experimental group (EG) was fed CED with oral gavage of AAP (120 mg/kg/d body weight) for an 8-wk period. After 2, 4, 6, and 8 wk, total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglyceride (TG) levels of the serum were determined by enzymatic methods. The results indicated that the polysaccharides significantly lowered the concentrations of serum TC and LDL-C compared with the CED control group (P