Microgreen nutrition, food safety, and shelf life: A review

Assessing light spectrum impact on growth and antioxidant properties of basil family microgreens

Understanding the influence of light spectra on plant growth and antioxidant activities is crucial for optimizing cultivation practices and enhancing crop quality. In this study, we investigated the effects of different light treatments on growth parameters and antioxidant activities in five plant species: peppermint, Thai basil, cumin, lemon basil, and green holy basil. Our results revealed distinct responses to varying light spectra, with green light consistently promoting taller plant heights across all species. Additionally, blue light induced notable increases in plant width for certain species. Analysis of antioxidant activities demonstrated dynamic fluctuations in Total Phenolic Content (TPC) and Flavonoid Content (TFC) among different light treatments and plant species. While white and red light generally promoted higher TPC levels, blue light unexpectedly exhibited the highest TPC levels at specific time points. Moreover, investigation into DPPH Radical Scavenging activity revealed diverse temporal responses to light spectra, with blue light demonstrating exceptional activity at early stages and white and red light showing heightened activity at later time points. These findings underscore the importance of tailored light regimes in optimizing growth parameters and enhancing antioxidant activities in cultivated plants, thereby offering promising avenues for sustainable agriculture and food production practices.

Emergence of microgreens as a valuable food, current understanding of their market and consumer perception: A review

Green leafy vegetables, especially microgreens are gaining popularity due to their high nutritional profiles, rich phytochemical content, and intense flavors. This review explores the growing commercial market for microgreens, especially in upscale dining and premium grocery outlets, highlighting consumer perceptions and their effect on market dynamics. Apart from these, the effect of modern agricultural methods that maximize the growth of microgreens is also examined. The value is anticipated to increase significantly, according to market predictions, from $1.7 billion in 2022 to $2.61 billion by 2029. Positive consumer views on microgreens health benefits drive this growth, although challenges such as varying levels of consumer awareness and income disparities affect sales. The review underscores the need for targeted research and strategic initiatives to enhance consumer understanding and improve cultivation methods to support market expansion in upcoming years.

Assessment of Vegetable Species for Microgreen Production in Unheated Greenhouses: Yield, Nutritional Composition, and Sensory Perception

Cultivating microgreens in central-southern Chile in unheated greenhouses offers a viable and productive alternative to growers. In 2023, two experiments were conducted in autumn and spring. These experiments involved the production of microgreens of eleven vegetable species. The tray system with the substrate was employed. Subsequently, agronomic, nutritional, and sensory perception variables were assessed. Despite notable fluctuations in external temperatures between these seasons, a diverse array of microgreens can be successfully cultivated, meeting local consumer preferences. Research indicates that microgreens grown under these conditions exhibit high nutritional quality, serving as a rich source of essential nutrients and bioactive compounds beneficial to human health. This nutritional value remains consistent across autumn and spring, establishing microgreens as a reliable and valuable food option. The observed acceptance and purchasing intentions among the surveyed population suggest a promising market opportunity for introducing these products regionally. Consumers appreciate microgreens' quality and nutritional advantages, underscoring their potential.

Green light is similarly effective in promoting plant biomass as red/blue light: a meta-analysis

Whether green light promotes or represses plant growth is an unresolved but important question, warranting a global meta-analysis of published data. We collected 136 datasets from 48 publications on 17 crop species, and calculated the green light effect for a range of plant traits. For each trait the effect was calculated as the ratio between the trait value attained under a red/blue background light plus green, divided by the value attained under the background light only, both having the same light intensity. Generally, green light strongly increased intrinsic water use efficiency (15%), the shoot-to-root ratio (13%), and decreased stomatal conductance (-15%). Moreover, green light increased fresh weight to a small extent (4%), but not plant dry weight, resulting in a reduced dry matter content (-2%). Hence, green light is similarly effective at increasing biomass as red and blue light. Green light also showed to increase leaf area (7%) and specific leaf area (4%; i.e. thinner leaves). Furthermore, effects of green light were species-dependent, with positive effects on biomass for lettuce and microgreens, and negative effects in basil and tomato. Our data suggest that future research should focus on the role of green light in modulating water loss, its putative role as a shade signal, and the causes for its species-specific effects on crop biomass.

Postharvest Quality of Arugula (Eruca sativa) Microgreens Determined by Microbiological, Physico-Chemical, and Sensory Parameters

(1) Background: Cultivating microgreens is emerging as an excellent market opportunity. Their easy, short, and sustainable production methods are the main reasons they are approved by growers. However, a feature that still prevents its further spread is the microbiological risk and their rapid senescence. The present study was conducted to evaluate the post-harvest storage and shelf life of arugula microgreens in different packaging through microbiological, physico-chemical, and sensory parameters; (2) Methods: Plants were stored at 5 °C in open air, vacuum sealed, and under modified atmosphere bags and tested at 0, 3, 5, 7, and 10 days; (3) Results: Microgreens stored in all packaging were safe for consumption within ten days. Regarding physical and chemical parameters, open packaging proved to be promising, with less weight loss and slower chlorophyll degradation. The sensory analysis demonstrated that the microgreens stored in the vacuum-sealed packaging showed a decrease in quality from the fifth day onwards for all attributes. However, the MAP presented good scores with a better visual quality, similar to the fresh microgreens.

Controlled Environment Ecosystem: A Cutting-Edge Technology in Speed Breeding

The controlled environment ecosystem is a meticulously designed plant growing chamber utilized for cultivating biofortified crops and microgreens, addressing hidden hunger and malnutrition prevalent in the growing population. The integration of speed breeding within such controlled environments effectively eradicates morphological disruptions encountered in traditional breeding methods such as inbreeding depression, male sterility, self-incompatibility, embryo abortion, and other unsuccessful attempts. In contrast to the unpredictable climate conditions that often prolong breeding cycles to 10-15 years in traditional breeding and 4-5 years in transgenic breeding within open ecosystems, speed breeding techniques expedite the achievement of breeding objectives and F1-F6 generations within 2-3 years under controlled growing conditions. In comparison, traditional breeding may take 5-10 years for plant population line creation, 3-5 years for field trials, and 1-2 years for variety release. The effectiveness of speed breeding in trait improvement and population line development varies across different crops, requiring approximately 4 generations in rice and groundnut, 5 generations in soybean, pea, and oat, 6 generations in sorghum, Amaranthus sp., and subterranean clover, 6-7 generations in bread wheat, durum wheat, and chickpea, 7 generations in broad bean, 8 generations in lentil, and 10 generations in Arabidopsis thaliana annually within controlled environment ecosystems. Artificial intelligence leverages neural networks and algorithm models to screen phenotypic traits and assess their role in diverse crop species. Moreover, in controlled environment systems, mechanistic models combined with machine learning effectively regulate stable nutrient use efficiency, water use efficiency, photosynthetic assimilation product, metabolic use efficiency, climatic factors, greenhouse gas emissions, carbon sequestration, and carbon footprints. However, any negligence, even minor, in maintaining optimal photoperiodism, temperature, humidity, and controlling pests or diseases can lead to the deterioration of crop trials and speed breeding techniques within the controlled environment system. Further comparative studies are imperative to comprehend and justify the efficacy of climate management techniques in controlled environment ecosystems compared to natural environments, with or without soil.

Microgreens and novel non-thermal seed germination techniques for sustainable food systems: a review

There are a number of cutting-edge techniques implemented in the germination process, including high pressure processing, ultrasonic, ultraviolet, light, non-thermal plasma, magnetic field, microwave radiation, electrolyzed oxidizing water, and plasma activated water. The influence of these technological advances on seed germination procedure is addressed in this review. The use of these technologies has several benefits, including the enhancement of plant growth rate and the modulation of bioactive chemicals like ABA, protein, and peroxidase concentrations, as well as the suppression of microbial development. Microgreens' positive health effects, such as their antioxidant, anticancer, antiproliferative/pro-oxidant, anti-obesity, and anti-inflammatory properties are extensively reviewed. The phytochemical and bioactive components of microgreens were investigated, including the concentrations of vitamin K, vitamin C, vitamin E, micro and macro nutrients, pro-vitamin A, polyphenols, and glucosinolates. Furthermore, the potential commercial uses of microgreens, as well as the current market transformation and prospects for the future are explored.

Effects of Organic Fertilizer on Photosynthesis, Yield, and Quality of Pakchoi under Different Irrigation Conditions

Water scarcity and the overuse of chemical fertilizers present significant challenges to modern agriculture, critically affecting crop photosynthesis, yield, quality, and productivity sustainability. This research assesses the impact of organic fertilizer on the photosynthetic attributes, yield, and quality of pakchoi under varying irrigation water conditions, including fresh water and brackish water. Findings reveal that the modified rectangular hyperbolic model most accurately captures the photosynthetic reaction to organic fertilization, outperforming other evaluated models. The maximum net photosynthesis rate (Pnmax), yield, soluble sugar (SS), and soluble protein content (SP) all exhibited a downward-opening quadratic parabolic trend with increasing amounts of organic fertilizer application. Specifically, under fresh-water irrigation, the optimal Pnmax, yield, SS, and SP were obtained at organic fertilizer rates of 65.77, 74.63, 45.33, and 40.79 kg/ha, respectively, achieving peak values of 20.71 µmol/(m2·s), 50,832 kg/ha, 35.63 g/kg, and 6.25 g/kg. This investigation provides a foundational basis for further research into the intricate relationship between water salinity stress and nutrient management, with the goal of crafting more sophisticated and sustainable farming methodologies. The insights gained could significantly influence organic fertilizer practices, promoting not only higher yields but also superior quality in agricultural outputs.

Transfer of Salmonella, Escherichia coli O157:H7 and Listeria monocytogenes from contaminated soilless substrate and seeds to microgreens

Microgreens can be contaminated by various preharvest sources including soilless substrate, plant nutrition solution, water and seeds. The aim of this study was to determine the transfer level of Salmonella, Shiga toxin-producing Escherichia coli O157:H7, and Listeria monocytogenes to the edible part of various type of microgreens from plant nutrient solution-soaked perlite as soilless substrate or seeds. Ampicillin resistant 3-strain cocktails of Salmonella and E. coli O157:H7 and non-resistant L. monocytogenes were independently inoculated into plant nutrient solution-soaked perlite and seeds in low (102-103 CFU/g) and high (105-106 CFU/g) populations. Twenty types of microgreens were grown in inoculated perlite. The seed inoculation was performed on five types of microgreens. Correlations between pathogen transfer levels with seed characteristics and harvest time were assessed. Pathogen populations (1.6 ± 0.2 to 7.7 ± 0.1 log CFU/g) transferred to microgreens were dependent on type of pathogen and microgreen but not affected by contamination source and inoculation level. The level of pathogen transferred to microgreens had a moderate to high negative correlations (R2) with seed surface area (-0.551 to -0.781), seed weight (-0.735 to -0.818), and harvest time (-0.332 to -0.919) when grown in Salmonella and E. coli O157:H7 inoculated perlite. This study suggests a high risk of pathogen population transferring to microgreens in case of seed or soilless substrate contamination when pathogen growth or survival is supported in plant nutrient solution.

Comparative study of the quality indices, antioxidant substances, and mineral elements in different forms of cabbage

BACKGROUND

As the second largest leafy vegetable, cabbage (Brassica oleracea L. var. capitata) is grown globally, and the characteristics of the different varieties, forms, and colors of cabbage may differ. In this study, five analysis methods-variance analysis, correlation analysis, cluster analysis, principal component analysis, and comprehensive ranking-were used to evaluate the quality indices (soluble protein, soluble sugar, and nitrate), antioxidant content (vitamin C, polyphenols, and flavonoids), and mineral (K, Ca, Mg, Cu, Fe, Mn, and Zn) content of 159 varieties of four forms (green spherical, green oblate, purple spherical, and green cow heart) of cabbage.

RESULTS

The results showed that there are significant differences among different forms and varieties of cabbage. Compared to the other three forms, the purple spherical cabbage had the highest flavonoid, K, Mg, Cu, Mn, and Zn content. A scatter plot of the principal component analysis showed that the purple spherical and green cow heart cabbage varieties were distributed to the same quadrant, indicating that their quality indices and mineral contents were highly consistent, while those of the green spherical and oblate varieties were irregularly distributed. Overall, the green spherical cabbage ranked first, followed by the green cow heart, green oblate, and purple spherical varieties.

CONCLUSIONS

Our results provide a theoretical basis for the cultivation and high-quality breeding of cabbage.

A comprehensive examination of microbial hazards and risks during indoor soilless leafy green production

Produce grown under controlled environment agriculture (CEA) is often assumed to have a reduced risk of pathogen contamination due to the low chance of exposure to outdoor contaminant factors. However, the 2021 outbreak and numerous recalls of CEA-grown lettuce and microgreens demonstrate the possibility of pathogen introduction during indoor production when there is a failure in the implementation of food safety management systems. Indoor production of commercial leafy greens, such as lettuce and microgreens, is performed across a range of protective structures from primitive household setups to advanced and partially automatized growing systems. Indoor production systems include hydroponic, aquaponic, and aeroponic configurations. Hydroponic systems such as deep water culture and nutrient film technique comprised of various engineering designs represent the main system types used by growers. Depending on the type of leafy green, the soilless substrate, and system selection, risk of microbial contamination will vary during indoor production. In this literature review, science-based pathogen contamination risks and mitigation strategies for indoor production of microgreens and more mature leafy greens are discussed during both pre-harvest and post-harvest stages of production.

The Use of Predictive Microbiology for the Prediction of the Shelf Life of Food Products

Microbial shelf life refers to the duration of time during which a food product remains safe for consumption in terms of its microbiological quality. Predictive microbiology is a field of science that focuses on using mathematical models and computational techniques to predict the growth, survival, and behaviour of microorganisms in food and other environments. This approach allows researchers, food producers, and regulatory bodies to assess the potential risks associated with microbial contamination and spoilage, enabling informed decisions to be made regarding food safety, quality, and shelf life. Two-step and one-step modelling approaches are modelling techniques with primary and secondary models being used, while the machine learning approach does not require using primary and secondary models for describing the quantitative behaviour of microorganisms, leading to the spoilage of food products. This comprehensive review delves into the various modelling techniques that have found applications in predictive food microbiology for estimating the shelf life of food products. By examining the strengths, limitations, and implications of the different approaches, this review provides an invaluable resource for researchers and practitioners seeking to enhance the accuracy and reliability of microbial shelf life predictions. Ultimately, a deeper understanding of these techniques promises to advance the domain of predictive food microbiology, fostering improved food safety practices, reduced waste, and heightened consumer confidence.

Microbiological hazards associated with the use of water in the post-harvest handling and processing operations of fresh and frozen fruits, vegetables and herbs (ffFVHs). Part 1 (outbreak data analysis, literature review and stakeholder questionnaire)

The contamination of water used in post-harvest handling and processing operations of fresh and frozen fruit, vegetables and herbs (ffFVHs) is a global concern. The most relevant microbial hazards associated with this water are: Listeria monocytogenes, Salmonella spp., human pathogenic Escherichia coli and enteric viruses, which have been linked to multiple outbreaks associated with ffFVHs in the European Union (EU). Contamination (i.e. the accumulation of microbiological hazards) of the process water during post-harvest handling and processing operations is affected by several factors including: the type and contamination of the FVHs being processed, duration of the operation and transfer of microorganisms from the product to the water and vice versa, etc. For food business operators (FBOp), it is important to maintain the microbiological quality of the process water to assure the safety of ffFVHs. Good manufacturing practices (GMP) and good hygienic practices (GHP) related to a water management plan and the implementation of a water management system are critical to maintain the microbiological quality of the process water. Identified hygienic practices include technical maintenance of infrastructure, training of staff and cooling of post-harvest process water. Intervention strategies (e.g. use of water disinfection treatments and water replenishment) have been suggested to maintain the microbiological quality of process water. Chlorine-based disinfectants and peroxyacetic acid have been reported as common water disinfection treatments. However, given current practices in the EU, evidence of their efficacy under industrial conditions is only available for chlorine-based disinfectants. The use of water disinfection treatments must be undertaken following an appropriate water management strategy including validation, operational monitoring and verification. During operational monitoring, real-time information on process parameters related to the process and product, as well as the water and water disinfection treatment(s) are necessary. More specific guidance for FBOp on the validation, operational monitoring and verification is needed.

Comparative Analysis of Volatile Compounds from Four Radish Microgreen Cultivars Based on Ultrasonic Cell Disruption and HS-SPME/GC-MS

The ultrasonic cell disruption method was used to efficiently extract isothiocyanates and other volatile compounds from radish microgreens. A total of 51 volatiles were identified and quantified by headspace solid-phase micro-extraction and gas chromatography-mass spectrometry (HS-SPME/GC-MS) in four radish microgreen cultivars, mainly including alcohols, aldehydes, isothiocyanates, sulfides, ketones, esters, terpenes, and hydrocarbons. The correlation between cultivars and volatile compounds was determined by chemometrics analysis, including principal component analysis (PCA) and hierarchical clustering heat maps. The aroma profiles were distinguished based on the odor activity value (OAV), odor contribution rate (OCR), and radar fingerprint chart (RFC) of volatile compounds. This study not only revealed the different flavor characteristics in four cultivars but also established a theoretical basis for the genetic improvement of radish microgreen flavors.

LC-MS- and 1H NMR-Based Metabolomics to Highlight the Impact of Extraction Solvents on Chemical Profile and Antioxidant Activity of Daikon Sprouts (Raphanus sativus L.)

Currently, the interest of consumers towards functional foods as source of bioactive compounds is increasing. The sprouts of Raphanus sativus var longipinnatus (Brassicaceae) are "microgreens" popular, especially in gourmet cuisine, for their appealing aspect and piquant flavour. They represent a functional food due to their high nutritional value and health-promoting effects. Herein, the sprouts of daikon were extracted by different solvent mixtures to highlight how this process can affect the chemical profile and the antioxidant activity. An in-depth investigation based on a preliminary LC-ESI/LTQOrbitrap/MS profiling was carried out, leading to the identification of nineteen compounds, including glucosinolates and hydroxycinnamic acid derivatives. An undescribed compound, 1-O-feruloyl-2-O-sinapoyl-β-D-glucopyranoside, was isolated, and its structure was elucidated by NMR spectroscopy. The phenolic content and radical scavenging activity (DPPH and TEAC assays), along with the ability to activate Nrf2 (Nrf2-mediated luciferase reporter gene assay) of polar extracts, were evaluated. The results showed the highest antioxidant activity for the 70% EtOH/H2O extract with a TEAC value of 1.95 mM and IC50 = 93.97 µg/mL in the DPPH assay. Some 50% and 70% EtOH/H2O extracts showed a pronounced concentration-dependent induction of Nrf2 activity. The extracts of daikon sprouts were submitted to 1H NMR experiments and then analyzed by untargeted and targeted approaches of multivariate data analysis to highlight differences related to extraction solvents.

Biochemical Compounds, Antioxidant Capacity, Leaf Color Profile and Yield of Basil (Ocimum sp.) Microgreens in Floating System

Basil is a great source of phytochemicals such as polyphenols, vitamin C, anthocyanin, and flavonoids. In this work, the biochemical compounds, antioxidant capacity, leaf color profile, and yield of 21 cultivars and genotypes of basil microgreen were investigated. Results showed that the highest antioxidant potential composite index (APCI) was measured in Persian Ablagh genotype (70.30). Twenty-one basil genotypes were classified into four clusters, including cluster 1 (lowest antioxidant capacity and total phenolic compounds), cluster 2 (lowest anthocyanin, vitamin C and APCI index), cluster 3 (highest vitamin C, total phenolic compounds, antioxidant capacity and APCI index), and cluster 4 (highest levels of anthocyanin). The principal components analysis (PCA) of basil genotypes showed diversity in terms of phytochemical components, and F1, F2, F3, and F4 explained the variation at the rate of 78.12%. The average annual temperature of the origin of basil seeds plays an important role in the synthesis of antioxidant content. Most of the seeds with moderate origin had a higher APCI index. The Persian Ablagh genotype, Violeto, and Kapoor cultivars can be recommended, according to their APCI index and yield. These cultivars can be used individually or in different ratios to produce different biochemical substances with different concentrations for various purposes.

Graphene-Based Sensors for the Detection of Microorganisms in Food: A Review

There is a constant need to maintain the quality of consumed food. In retrospect to the recent pandemic and other food-related problems, scientists have focused on the numbers of microorganisms that are present in different food items. As a result of changes in certain environmental factors such as temperature and humidity, there is a constant risk for the growth of harmful microorganisms, such as bacteria and fungi, in consumed food. This questions the edibility of the food items, and constant monitoring to avoid food poisoning-related diseases is required. Among the different nanomaterials used to develop sensors to detect microorganisms, graphene has been one of the primary materials due to its exceptional electromechanical properties. Graphene sensors are able to detect microorganisms in both a composite and non-composite manner, due to their excellent electrochemical characteristics such as their high aspect ratios, excellent charge transfer capacity and high electron mobility. The paper depicts the fabrication of some of these graphene-based sensors, and their utilization to detect bacteria, fungi and other microorganisms that are present in very small amounts in different food items. In addition to the classified manner of the graphene-based sensors, this paper also depicts some of the challenges that exist in current scenarios, and their possible remedies.

Alfalfa, Cabbage, Beet and Fennel Microgreens in Floating Hydroponics-Perspective Nutritious Food?

Microgreens are young plants of various vegetables, medicinal and aromatic plants, cereals and edible wild plants that were first associated with nouvelle cuisine as decoration in dishes due to their attractive appearance and strong flavor. Recently, they have become more sought after in the market due to their high nutritional value. This is due to the growing interest of consumers in a healthy lifestyle that includes a varied diet with emphasis on fresh, functional foods. Nowadays, commercial production of microgreens is shifting to modern hydroponic systems due to their numerous advantages, such as accelerated plant growth and biomass production, earlier harvesting, and more production cycles that positively affect yield and chemical composition. Therefore, the aim of this study was to determine the content of specialized metabolites and antioxidant capacity of hydroponically grown alfalfa (Medicago sativa) cv. 'Kangaroo', yellow beet (Beta vulgaris var. conditiva) cv. 'Yellow Lady', red cabbage (Brassica oleracea L. var. rubra) cv. 'Red Carpet', and fennel (Foeniculum vulgare) cv. 'Aganarpo' microgreens. The highest content of total phenols (408.03 mg GAE/100 g fw), flavonoids (214.47 mg GAE/100 g fw), non-flavonoids (193.56 mg GAE/100 g fw) and ascorbic acid (74.94 mg/100 g fw) was found in fennel microgreens. The highest content of all analyzed chlorophyll pigments (Chl_a 0.536 mg/g fw, Chl_b 0.248 mg/g fw, and TCh 0.785 mg/g fw) was found in alfalfa microgreens. However, in addition to alfalfa, high levels of chlorophyll a (0.528 mg/g fw), total chlorophyll (0.713 mg/g fw) and the highest level of total carotenoids (0.196 mg/g fw) were also detected in fennel microgreens. The results suggest that microgreens grown on perlite in floating hydroponics have high nutritional potential as a functional food important for human health and therefore could be recommended for daily diet.

Young Shoots of Red Beet and the Root at Full Maturity Inhibit Proliferation and Induce Apoptosis in Breast Cancer Cell Lines

Modern medicine is struggling with the problem of fully effective treatment of neoplastic diseases despite deploying innovative chemotherapeutic agents. Therefore, undertaking cancer-prevention measures, such as proper eating habits, should be strongly recommended. The present research aimed to compare the effects of juice from young shoots of beetroot compared to juice from root at full maturity on human breast cancer and normal cells. The juice from young shoots, both in the native and digested form, was most often a significantly stronger inhibitor of the proliferation of both analyzed breast cancer cell lines (MCF-7 and MDA-MB-231), compared to the native and digested juice from red beetroot. Regardless of juice type, a significantly greater reduction was most often shown in the proliferation of estrogen-dependent cells (MCF-7 line) than of estrogen-independent cells (MDA-MB-231 line). All analyzed types of beetroot juice and, in particular, the ones from young shoots and the root subjected to digestion and absorption, exerted an antiproliferative and apoptotic effect (pinpointing the internal apoptosis pathway) on the cells of both cancer lines studied. There is a need to continue the research to comprehensively investigate the factors responsible for both these effects.

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.

Brassicaceae microgreens: A novel and promissory source of sustainable bioactive compounds

Microgreens are novel foods with high concentrations of bioactive compounds and can be grown easily and sustainably. Among all the microgreens genera produced, Brassicaceae stand out because of the wide evidence about their beneficial effects on human health attributed to phenolic compounds, vitamins, and particularly glucosinolates and their breakdown products, isothiocyanates and indoles. The phytochemical profile of each species is affected by the growing conditions in a different manner. The agronomic practices that involve these factors can be used as tools to modulate and enhance the concentration of certain compounds of interest. In this sense, the present review summarizes the impact of substrates, artificial lighting, and fertilization on bioactive compound profiles among species. Since Brassicaceae microgreens, rich in bioactive compounds, can be considered functional foods, we also included a discussion about the health benefits associated with microgreens' consumption reported in the literature, as well as their bioaccessibility and human absorption. Therefore, the present review aimed to analyze and systematize cultivation conditions of microgreens, in terms of their effects on phytochemical profiles, to provide possible strategies to enhance the functionality and health benefits of Brassicaceae microgreens.

Formation, immunomodulatory activities, and enhancement of glucosinolates and sulforaphane in broccoli sprouts: a review for maximizing the health benefits to human

Broccoli sprouts have been considered as functional foods which have received increasing attention because they have been highly prized for glucosinolates, phenolics, and vitamins in particular glucosinolates. One of hydrolysates-sulforaphane from glucoraphanin is positively associated with the attenuation of inflammatory, which could reduce diabetes, cardiovascular and cancer risk. In recent decades, the great interest in natural bioactive components especially for sulforaphane promotes numerous researchers to investigate the methods to enhance glucoraphanin levels in broccoli sprouts and evaluate the immunomodulatory activities of sulforaphane. Therefore, glucosinolates profiles are different in broccoli sprouts varied with genotypes and inducers. Physicochemical, biological elicitors, and storage conditions were widely studied to promote the accumulation of glucosinolates and sulforaphane in broccoli sprouts. These inducers would stimulate the biosynthesis pathway gene expression and enzyme activities of glucosinolates and sulforaphane to increase the concentration in broccoli sprouts. The immunomodulatory activity of sulforaphane was summarized to be a new therapy for diseases with immune dysregulation. The perspective of this review served as a potential reference for customers and industries by application of broccoli sprouts as a functional food and clinical medicine.

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.

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.

High Growing Temperature Changes Nutritional Value of Broccoli (Brassica oleracea L. convar. botrytis (L.) Alef. var. cymosa Duch.) Seedlings

High temperature (HT) causes physiological and biochemical changes in plants, which may influence their nutritional potential. This study aimed to evaluate the nutritional value of broccoli seedlings grown at HT on the level of phytochemicals, macro- and microelements, antioxidant capacity, and their extracts' in vitro cytotoxicity. Total phenols, soluble sugars, carotenoids, quercetin, sinapic, ferulic, p-coumaric, and gallic acid were induced by HT. Contrarily, total flavonoids, flavonols, phenolic acids, hydroxycinnamic acids, proteins, glucosinolates, chlorophyll a and b, and porphyrins were reduced. Minerals As, Co, Cr, Hg, K, Na, Ni, Pb, Se, and Sn increased at HT, while Ca, Cd, Cu, Mg, Mn, and P decreased. ABTS, FRAP, and β-carotene bleaching assay showed higher antioxidant potential of seedlings grown at HT, while DPPH showed the opposite. Hepatocellular carcinoma cells were the most sensitive toward broccoli seedling extracts. The significant difference between control and HT-grown broccoli seedling extracts was recorded in mouse embryonal fibroblasts and colorectal carcinoma cells. These results show that the temperature of seedling growth is a critical factor for their nutritional value and the biological effects of their extracts and should definitely be taken into account when growing seedlings for food purposes.

Prospects of microgreens as budding living functional food: Breeding and biofortification through OMICS and other approaches for nutritional security

Nutrient deficiency has resulted in impaired growth and development of the population globally. Microgreens are considered immature greens (required light for photosynthesis and growing medium) and developed from the seeds of vegetables, legumes, herbs, and cereals. These are considered "living superfood/functional food" due to the presence of chlorophyll, beta carotene, lutein, and minerals like magnesium (Mg), Potassium (K), Phosphorus (P), and Calcium (Ca). Microgreens are rich at the nutritional level and contain several phytoactive compounds (carotenoids, phenols, glucosinolates, polysterols) that are helpful for human health on Earth and in space due to their anti-microbial, anti-inflammatory, antioxidant, and anti-carcinogenic properties. Microgreens can be used as plant-based nutritive vegetarian foods that will be fruitful as a nourishing constituent in the food industryfor garnish purposes, complement flavor, texture, and color to salads, soups, flat-breads, pizzas, and sandwiches (substitute to lettuce in tacos, sandwich, burger). Good handling practices may enhance microgreens'stability, storage, and shelf-life under appropriate conditions, including light, temperature, nutrients, humidity, and substrate. Moreover, the substrate may be a nutritive liquid solution (hydroponic system) or solid medium (coco peat, coconut fiber, coir dust and husks, sand, vermicompost, sugarcane filter cake, etc.) based on a variety of microgreens. However integrated multiomics approaches alongwith nutriomics and foodomics may be explored and utilized to identify and breed most potential microgreen genotypes, biofortify including increasing the nutritional content (macro-elements:K, Ca and Mg; oligo-elements: Fe and Zn and antioxidant activity) and microgreens related other traits viz., fast growth, good nutritional values, high germination percentage, and appropriate shelf-life through the implementation of integrated approaches includes genomics, transcriptomics, sequencing-based approaches, molecular breeding, machine learning, nanoparticles, and seed priming strategiesetc.

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.

Evaluating the Alignment and Quality of Microgreens Training Materials Available on the Internet: A Content Analysis

Interest in microgreens, young, edible seedlings of a variety of vegetables, spices, and herbs, is growing worldwide. A recent national survey of the U.S. microgreen industry reported 48% of 176 growers learned to grow microgreens by viewing websites and videos on the internet. However, it is unknown if the content related to growing microgreens is aligned with regulations and clearly presented. The aim of this research was to conduct a content analysis to determine alignment with the Food Safety and Modernization Act Produce Safety Rule (PSR)and the presentation quality of existing microgreen training materials available on the internet. Microgreen training materials were collected using two search engines - Google and YouTube. A deductive approach was used to inform the development of three coding manuals to evaluate the training materials meeting the eligibility criteria. One was used to determine the alignment of the content and was based on the PSR. The other two manuals were used to determine the presentation quality of Google and YouTube training materials according to CDC's Quality E-learning Checklist. A total of 223 training materials (86 Google and 137 YouTube), which fulfilled the inclusion criteria, were selected for the analysis. The results of the alignment with the PSR revealed that both sources minimally covered food safety principles with several areas minimally or not addressing specific information (e.g., water testing, worker training, environmental monitoring, and record keeping). In addition, some food safety information was unclear or presented conflicting information (e.g., requirement of washing microgreens, cleaning and sanitization methods, seed treatment methods, and waste management). The Google and YouTube quality scoring systems resulted in a mean quality score of 15.81 and 22 of a maximum score of 28, respectively. These findings indicate the quality and alignment with the PSR of microgreen training materials need to be improved.

Aptasensor Based on Microfluidic for Foodborne Pathogenic Bacteria and Virus Detection: A Review

In today's world, which is entangled with numerous foodborne pathogenic bacteria and viruses, it appears to be essential to rethink detection methods of these due to the importance of food safety in our lives. The vast majority of detection methods for foodborne pathogenic bacteria and viruses have suffered from sensitivity and selectivity due to the small size of these pathogens. Besides, these types of sensing approaches can improve on-site detection platforms in the fields of food safety. In recent, microfluidics systems as new emerging types of portable sensing approaches can introduce efficient and simple biodevice by integration with several analytical methods such as electrochemical, optical and colorimetric techniques. Additionally, taking advantage of aptamer as a selective bioreceptor in the sensing of microfluidics system has provided selective, sensitive, portable and affordable sensing approaches. Furthermore, some papers use increased data transferability ability and computational power of these sensing platforms by exploiting smartphones. In this review, we attempted to provide an overview of the current state of the recent aptasensor based on microfluidic for screening of foodborne pathogenic bacteria and viruses. Working strategies, benefits and disadvantages of these sensing approaches are briefly discussed.

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 7^th, 8^th, and 9^th 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.

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.

The Inclusion of Green Light in a Red and Blue Light Background Impact the Growth and Functional Quality of Vegetable and Flower Microgreen Species

Microgreens are edible seedlings of vegetables and flowers species which are currently considered among the five most profitable crops globally. Light-emitting diodes (LEDs) have shown great potential for plant growth, development, and synthesis of health-promoting phytochemicals with a more flexible and feasible spectral manipulation for microgreen production in indoor farms. However, research on LED lighting spectral manipulation specific to microgreen production, has shown high variability in how these edible seedlings behave regarding their light environmental conditions. Hence, developing species-specific LED light recipes for enhancement of growth and valuable functional compounds is fundamental to improve their production system. In this study, various irradiance levels and wavelengths of light spectrum produced by LEDs were investigated for their effect on growth, yield, and nutritional quality in four vegetables (chicory, green mizuna, china rose radish, and alfalfa) and two flowers (french marigold and celosia) of microgreens species. Microgreens were grown in a controlled environment using sole-source light with different photosynthetic photon flux density (110, 220, 340 µmol m−2 s−1) and two different spectra (RB: 65% red, 35% blue; RGB: 47% red, 19% green, 34% blue). At harvest, the lowest level of photosynthetically active photon flux (110 µmol m−2 s−1) reduced growth and decreased the phenolic contents in almost all species. The inclusion of green wavelengths under the highest intensity showed positive effects on phenolic accumulation. Total carotenoid content and antioxidant capacity were in general enhanced by the middle intensity, regardless of spectral combination. Thus, this study indicates that the inclusion of green light at an irradiance level of 340 µmol m−2 s−1 in the RB light environment promotes the growth (dry weight biomass) and the accumulation of bioactive phytochemicals in the majority of the microgreen species tested.

Glycerophospholipidomics of Five Edible Oleaginous Microgreens

Microgreens are a special type of vegetal product, born as a culinary novelty (traditionally used to garnish gourmet dishes) and then progressively studied for their potentially high content in nutraceuticals, like polyphenolic compounds, carotenoids, and glucosinolates, also in the perspective of implementing their cultivation in space stations/colonies. Among further potential nutraceuticals of microgreens, lipids have received very limited attention so far. Here, glycerophospholipids contained in microgreens of typical oleaginous plants, namely, soybean, chia, flax, sunflower, and rapeseed, were studied using hydrophilic interaction liquid chromatography (HILIC), coupled to high-resolution Fourier transform mass spectrometry (FTMS) or low-resolution collisionally induced dissociation tandem mass spectrometry (CID-MS²) with electrospray ionization (ESI). Specifically, this approach was employed to obtain qualitative and quantitative profiling of the four main classes of glycerophospholipids (GPL) found in the five microgreens, i.e., phosphatidylcholines (PC), phosphatidylethanolamines (PE), phosphatidylglycerols (PG), and phosphatidylinositols (PI). Saturated chains with 16 and 18 carbon atoms and unsaturated 18:X (with X = 1-3) chains emerged as the most common fatty acyl substituents of those GPL; a characteristic 16:1 chain (including a C═C bond between carbon atoms 3 and 4) was also found in some PG species. Among polyunsaturated acyl chains, the 18:3 one, likely referred mainly to α-linolenic acid, exhibited a relevant incidence, with the highest estimated amount (corresponding to 160 mg per 100 g of lyophilized vegetal tissue) found for chia. This outcome opens interesting perspectives for the use of oleaginous microgreens as additional sources of essential fatty acids, especially in vegetarian/vegan diets.

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.

Barley microgreen incorporation in diet-controlled diabetes and counteracted aflatoxicosis in rats

Increased environmental pollution and unhealthy lifestyle are blamed for escalated chronic diseases. Exposure to aflatoxins was recently suggested to have a role in the increased incidence of type 2 diabetes mellitus. Diet modification and consumption of different functional food are now gaining attention, especially in diabetes management. This study investigates the effect of a diet containing barley microgreen against diabetes induced by streptozotocin with or without aflatoxin administration in rats. Barley microgreen was rich in 3'-Benzyloxy-5,6,7,4'-tetramethoxyflavone (48.8% of total) followed by 5β,7βH,10α-Eudesm-11-en-1α-ol (18.46%). Streptozotocin injection and/or aflatoxin administration significantly elevated glucose level, decreased insulin level, decreased β-cell function, deteriorated liver and kidney function parameters, and induced oxidative stress in the liver. Histopathology revealed irregular small-sized islets and decreased area % of insulin-positive beta cells in the pancreas, hepatic degeneration, nephropathy, and neuropathy in diabetic and/or aflatoxin administered rats compared to control. Barley microgreen diet fed to diabetic rats with or without aflatoxin alleviated all evaluated parameters. Barley microgreen diet also ameliorated the toxic effect of aflatoxin. In conclusion, exposure to aflatoxin aggravated diabetes and its complication. The incorporation of barley microgreen in the diet was able to control type 2 diabetes mellitus and the improved outcomes observed with barley microgreen treatments involved or occurred in conjunction with improved biomarkers of oxidative stress.

Effects of Different Light Spectra on Final Biomass Production and Nutritional Quality of Two Microgreens

To improve microgreen yield and nutritional quality, suitable light spectra can be used. Two species-amaranth (Amaranthus tricolor L.) and turnip greens (Brassica rapa L. subsp. oleifera (DC.) Metzg)-were studied. The experiment was performed in a controlled LED environment growth chamber (day/night temperatures of 24 ± 2 °C, 16 h photoperiod, and 50/60% relative humidity). Three emission wavelengths of a light-emitting diode (LED) were adopted for microgreen lighting: (1) white LED (W); (2) blue LED (B), and (3) red LED (R); the photosynthetic photon flux densities were 200 ± 5 µmol for all light spectra. The response to light spectra was often species-specific, and the interaction effects were significant. Morphobiometric parameters were influenced by species, light, and their interaction; at harvest, in both species, the fresh weight was significantly greater under B. In amaranth, Chl a was maximized in B, whereas it did not change with light in turnip greens. Sugar content varied with the species but not with the light spectra. Nitrate content of shoots greatly varied with the species; in amaranth, more nitrates were measured in R, while no difference in turnip greens was registered for the light spectrum effect. Polyphenols were maximized under B in both species, while R depressed the polyphenol content in amaranth.

Shoot Production and Mineral Nutrients of Five Microgreens as Affected by Hydroponic Substrate Type and Post-Emergent Fertilization

As a new specialty crop with high market value, microgreens are vegetable or herb seedlings consumed at a young age, 7–21 days after germination. They are known as functional food with high concentrations of mineral nutrients and health beneficial phytochemicals. Microgreen industry lacks standardized recommendations on cultural practices including species/variety selection, substrate choice, and fertilization management. This study evaluated shoot growth and mineral nutrient concentrations in five microgreens including four Brassica and one Raphanus microgreens as affected by four hydroponic pad types and post-emergent fertilization in two experiments in January and February 2020. The five microgreens varied in their shoot height, fresh, dry shoot weights, and mineral nutrient concentrations with radish producing the highest fresh and dry shoot weights. Radish had the highest nitrogen (N) concentration and mustard had the highest phosphorus (P) concentrations when grown with three hydroponic pads except for hemp mat. Hydroponic pad type altered fresh, dry shoot weights, and mineral nutrients in tested microgreens. Microgreens in hemp mat showed the highest shoot height, fresh, dry shoot weights, and potassium (K) concentration, but the lowest N concentration in one or two experiments. One time post-emergent fertilization generally increased shoot height, fresh, dry shoot weights, and macronutrient concentrations in microgreens.

Bacteriological safety of sprouts: A brief review

The germination process causes changes in the chemical composition of seeds that improves the nutritional value of sprouts, while decreasing their microbiological safety, since the germination conditions are ideal for bacterial growth as well. This review explores the bacteriological safety of sprouts and their involvement in foodborne illness outbreaks, worldwide. Additionally, approaches to improve the shelf-life and microbiological safety of sprouts are discussed. According to the literature, sprout consumption is associated with more than 60 outbreaks of foodborne illness worldwide, since 1988. Alfalfa sprouts were most commonly involved in outbreaks and the most commonly implicated pathogens were Salmonella and pathogenic Escherichia coli (especially, Shiga toxin producing E. coli). In the pre-harvest stage, the implementation of good agricultural practices is an important tool for producing high-quality seeds. In the post-harvest stage, several methods of seed decontamination are used commercially, or have been investigated by researchers. After germination, seedlings should be kept under refrigeration and, if possible, cooked before consumption. Finally, microbiological analyses should be performed at all stages to monitor the hygiene of the sprout production process.

Effect of Red Cabbage Sprouts Treating with Organic Acids on the Content of Polyphenols, Antioxidant Properties and Colour Parameters

In recent years, there has been a great deal of consumer interest in consuming vegetables in the form of sprouts, characterized by high nutritional value. The disadvantage of sprouts is the loss of bioactive compounds during storage and the relatively short shelf life, due to the fact that they are a good medium for microorganisms, especially yeasts and molds. The aim of the study was to compare the content of polyphenols, antioxidant properties, color and microbiological quality of red cabbage sprouts preserved by the use of mild organic acids: Citric, ascorbic, lactic, acetic and peracetic. In the study, the content of polyphenols and antioxidant properties of sprouts was examined using the spectrophotometric method, instrumental color measurement was done using an “electronic eye” and the content of mold, yeast and the total number of mesophilic microorganisms was determined using the plate inoculation method. Taking into account the content of polyphenols and the antioxidant potential of sprouts, it was found that the addition of all organic acids contributed to the preservation of the tested compounds during their 14-day storage under refrigerated conditions, depending on the type of organic acid used, from 71 to 86% for polyphenols and from 75 to 96% for antioxidant properties. The best results were obtained by treating the sprouts with peracetic acid and ascorbic acid, respectively, at a concentration of 80 ppm and 1%. The conducted research on the possibility of extending the storage life and preserving the bioactive properties of fresh sprouts showed that the use of peracetic acid in the form of an aqueous solution during pre-treatment allows to reduce the content of microorganisms by one logarithmic order. Ascorbic acid did not reduce the content of microorganisms in the sprout samples tested. Considering the content of bioactive ingredients, as well as the microbiological quality of fresh sprouts, it can be said that there is a great need to use mild organic acids during the pre-treatment of sprouts in order to maintain a high level of health-promoting ingredients during their storage, which may also contribute to their prolongation durability.

Quality Evaluation of Indoor-Grown Microgreens Cultivated on Three Different Substrates

The microgreens are innovative products in the horticultural sector. They are appreciated by consumers thanks to their novelty and health-related benefits, having a high antioxidant concentration. This produce can be adopted for indoor production using hydroponic systems. The aim of the present work was to investigate the influence of three growing media (vermiculite, coconut fiber, and jute fabric) on yield and quality parameters of two basil varieties (Green basil—Ocimum basilicum L., Red basil—Ocimum basilicum var. Purpurecsens) and rocket (Eruca sativa Mill.) as microgreens. Microgreens were grown in floating, in a Micro Experimental Growing (MEG®) system equipped with LED lamps, with modulation of both energy and spectra of the light supplied to plants. Results showed high yield, comprised from 2 to 3 kg m−2. Nutritional quality varied among species and higher antioxidant compounds were found in red basil on vermiculite and jute. Coconut fiber allowed the differentiation of crop performance in terms of sucrose and above all nitrate. In particular, our results point out that the choice of the substrate significantly affected the yield, the dry matter percentage and the nitrate concentration of microgreens, while the other qualitative parameters were most influenced by the species.

Nutritional metabolites in Brassica rapa subsp. chinensis var. parachinensis (choy sum) at three different growth stages: Microgreen, seedling and adult plant

Choy sum is a commonly consumed Asian green leafy brassica vegetable. A comprehensive spectrum of nutritional important metabolites, including amino acids, plant sugars, essential minerals, vitamins (A, B9, E, and K1) and glucosinolates were systematically quantified using LC-QQQ-MS, GC-QQQ-MS and ICP-MS. Significant metabolic profile shifts were observed during the three major developmental stages (microgreen, seedling and adult) studied. Primary metabolites, especially essential amino acids decreased while most plant sugars increased from microgreens to seedlings. Carotenoids, such as violaxanthin, neoxanthin, together with vitamin K1 were higher in the seedlings whereas CHO-folate vitamers and β-cryptoxanthin were much lower in adult plants. Most essential minerals were concentrated in the microgreens, while sodium increased in adult plants. Aliphatic glucosinolates in microgreens were converted to indolic glucosinolates in the seedlings and further to aromatic glucosinolates in the adults. Overall findings reveal that most of the nutritional metabolites were concentrated either in the microgreens or seedlings.

Fertilization and Pre-Sowing Seed Soaking Affect Yield and Mineral Nutrients of Ten Microgreen Species

Microgreens, vegetable or herb seedlings consumed at a young growth stage, are considered to be a functional food with high concentrations of mineral nutrients and healthy beneficial bioactive compounds. The production of microgreens has been increasing in recent years. Vegetable growers are interested in growing microgreens as a new specialty crop due to their high market value, popularity, and short production cycles. However, there is a lack of research-based crop-specific recommendations for cultural practices including fertilization, pre-sowing seed treatments, and their effects on nutritional facts of microgreens. Ten microgreen species were evaluated for their shoot growth and mineral nutrient concentrations as affected by one-time post-emergence fertilization and pre-sowing seed soaking in two repeated experiments, from November 2018 to January 2019, in a greenhouse. The microgreen species varied in fresh and dry shoot weights, shoot height, visual rating, as well as macro- and micro-nutrient concentrations. Fertilization with a general-purpose soluble fertilizer (20-20-20 with micronutrients) at a rate of 100 mg·L−1 nitrogen (N) increased fresh shoot weight, and macro- and micro-nutrient concentrations in one or both experiments, with the exception of decreasing concentrations of calcium (Ca), magnesium (Mg), and manganese (Mn). Seed soaking consistently decreased fresh or dry shoot weight and nutrient concentrations when there was a significant effect.

The effect of dissolved oxygen on microgreen productivity

The effect of oxygen dissolved in water was researched (1.3 mg/l – without saturation, 6.1 mg/l – air saturation, 14.7 mg/l – oxygen saturation) on the microgreen productivity of “Ivolga” variety wheat of and ‘Aida’ variety lentils. It was found that the enrichment of water for seed germination with oxygen stimulates the speedy germination and receipt of wheat and lentils sprouts 1 day faster than in the variant without saturation. An increase in oxygen concentration contributes to the rapid root system growth of the researched cultures, stimulates the formation of 2 order roots, accelerates the development of the overhead plant parts without dry weight loss. On the 7th day of cultivation, the wet weight of wheat increased by 21% in the variant with air saturation and 56% with oxygen saturation, wet weight of lentils – by 57% and 77%, respectively. Both a deficiency and an excess of oxygen in water can adversely affect the content of basic pigments. Therefore, it is necessary to select the species composition of cultures for composing multicomponent mixtures, to obtain higher microgreen quality when grown on oxygen-rich solutions.

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.