Environmental factors influencing the growth and pathogenicity of microgreens bound for the market: a review

Abstract

The world is experiencing a global push toward smart agriculture to help feed the burgeoning population by increasing food security while reducing the carbon footprint of food production. The guidelines for healthy eating have increased globally from five to seven servings of vegetables a day and this had led to the quest for a sustainable form of vegetable production that will reduce the carbon footprint and still provide consumers with the required nutrients. Microgreens contain more nutrients than some mature vegetables and can be cultivated on vertical farms, offering a different approach with the potential to resolve environmental and health challenges. Microgreens are young plantlets grown from the seeds of edible leafy vegetables and are usually eaten raw. They contain high levels of bioactive compounds and can be processed into oils to create valuable cosmetic products. Microgreens have become well-known to chefs and are gaining popularity in upmarket grocery outlets. Consequently, growing microgreens are presenting huge market opportunities worldwide. Their nutritional benefits, easy production methods and short production cycle are some of the reasons they are attractive to growers. The most important factors affecting the growth of microgreens are micro and macro-climates. One challenge to producing microgreens is that the growing environment is ideal for microbial organisms to thrive. As such, microgreens are prone to foodborne pathogens such as E. coli, Listeria and Salmonella. Consequently, the microgreens industry is facing various setbacks including product recalls from Salmonella and Listeria food poisoning outbreaks. In addition, the short shelf-life of microgreens is a serious challenge for getting microgreens to market, this is driving studies in several post-harvest treatments. This review examines the nutrient content and health benefits of microgreens and factors affecting microgreens' growth: temperature, humidity, photoperiod, fertilization, etc. and post-harvest treatments, all of which can potentially impact microbial growth, the phytochemical content and the physical appearance of microgreens bound for the market.

Factors Affecting Production, Nutrient Translocation Mechanisms, and LED Emitted Light in Growth of Microgreen Plants in Soilless Culture

“…95,96 The agricultural and horticultural microgreen plant requires specific temperatures and humidity for production in closed and open systems. Temperature and humidity of 30−33 °C, 75−80% for rice grass, 97 15−32 °C, 80−85% for barley grass, 98 16−27 °C, 75−80% for oat grass, 99 23−28 °C, 60−70% for wheat grass, 100 29−32 °C, 30% for jowar grass, 101 25−34 °C, 52−88% for maize grass, 102 10−21 °C, 8−80% for buckwheat, 103 21−26 °C, 14−16% for chickpea, 104 18−21 °C, 50−60% for mint, 105 17−27 °C, 60−70% for coriander, 106 21 °C, 50−60% for basil, 107 110 21 °C, 50−70% for shisho, 111 −1.11 °C, 50−75% for sorrel, 112 18−23 °C, 60−70% for sage, 113 18−23 °C, 40− 60% for beet, 114 15−24 °C, 50−70% for chard, 115 24−26 °C, 11−96% for quinoa, 116 22−26 °C, 100% for spinach, 117 33−36 °C, 80% for chives, 118 32−50 °C, 65−75% for garlic, 119 18−23 °C, 95−100% for leek, 120 55−75 °C, 40−50% for onion, 121 15−21 °C, 60−70% for carrot, 122 14−26 °C, 90−95% for celery, 123 16−18 °C, 58−63% for dill, 124 60−70 °C, 50−65% for fennel, 125 10−29 °C, 50−60% for radish, 126 15−17 °C, 50−60% for aster cress, 127 15−21 °C, 76% for mustard, 128 7.2−29.4 °C, 55−65% for kale, 129 25−30 °C, 40−70% for kohlrabi, 130 7.2−18 °C, 90−95% for arugula, 131 25 °C day/23 °C night, 60% for sunflower, 132 25−34 °C, 50−60% for linseed, 133 23−25 °C, 90−95% for chicory,…”

“…The agricultural and horticultural microgreen plant requires specific temperatures and humidity for production in closed and open systems. Temperature and humidity of 30–33 °C, 75–80% for rice grass, 15–32 °C, 80–85% for barley grass, 16–27 °C, 75–80% for oat grass, 23–28 °C, 60–70% for wheat grass, 29–32 °C, 30% for jowar grass, 25–34 °C, 52–88% for maize grass, 10–21 °C, 8–80% for buckwheat, 21–26 °C, 14–16% for chickpea, 18–21 °C, 50–60% for mint, 17–27 °C, 60–70% for coriander, 21 °C, 50–60% for basil, 24–29 °C, 75% for rosemary, 32 °C, 95–100% for parsley, 9.2–23.8 °C, 50–100% for saltwort, 21 °C, 50–70% for shisho, −1.11 °C, 50–75% for sorrel, 18–23 °C, 60–70% for sage, 18–23 °C, 40–60% for beet, 15–24 °C, 50–70% for chard, 24–26 °C, 11–96% for quinoa, 22–26 °C, 100% for spinach, 33–36 °C, 80% for chives, 32–50 °C, 65–75% for garlic, 18–23 °C, 95–100% for leek, 55–75 °C, 40–50% for onion, 15–21 °C, 60–70% for carrot, 14–26 °C, 90–95% for celery, 16–18 °C, 58–63% for dill, 60–70 °C, 50–65% for fennel, 10–29 °C, 50–60% for radish, 15–17 °C, 50–60% for aster cress, 15–21 °C, 76% for mustard, 7.2–29.4 °C, 55–65% for kale, 25–30 °C, 40–70% for kohlrabi, 7.2–18 °C, 90–95% for arugula, 25 °C day/23 °C night, 60% for sunflower, 25–34 °C, 50–60% for linseed, 23–25 °C, 90–95% for chicory, 15–18 °C, 95–98% for endive, 20 °C, 80% for lettuce, 15–21 °C, 40–50% for beans, 12–25 °C, 40–50% for welsh onion, 12–25 °C, 40–50% for long green onion, and 23–32 °C, 90–95% for red swiss chard are required for microgreen plant production.…”

A comprehensive review on the antioxidant activities and health benefits of microgreens: current insights and future perspectives

“…Environmental factors play a crucial role in the synthesis and accumulation of antioxidants in microgreens. Providing optimal growing conditions, including appropriate light, temperature, humidity, and nutrient supply, can enhance antioxidant production (Abaajeh et al ., 2023). The optimum temperature and harvest time for maximum yield determined for six microgreen crops ranged from 24 °C to 28 °C and from the 6th to 13th day, respectively (Dhaka et al ., 2023).…”

Antioxidant Activity of Microgreens, Potential of Use. Review of the Subject Field

“…Микрозелень  НАУЧНОЕ ОБОЗРЕНИЕ № 4, 2023   БИОЛОГИЧЕСКИЕ НАУКИ  также является источником витаминов, особенно витаминов С и Е. Витамин С действует как водорастворимый антиоксидант, укрепляя иммунную систему, способствуя синтезу коллагена и защищая клетки от окислительного повреждения. С другой стороны, витамин Е, жирорастворимый антиоксидант, защищает клеточные мембраны и липиды от окислительного стресса [60]. Включение микрозелени в рацион может способствовать соблюдению рекомендуемой суточной дозы необходимых витаминов, кроме того, микрозелень содержит микроэлементы, такие как селен и цинк, которые действуют как важные кофакторы антиоксидантной активности ферментов [1].…”