A Preliminary Examination of the Relationship Between Nutrient Formulation, Harvest Time, and Postharvest Processing for Antioxidant Response in Broccoli Microgreens

Broccoli microgreens are well suited for growth in indoor vertical farm systems; however, the antioxidant content of produce grown in these systems can be low. This study presents a preliminary examination of the impact of preharvest and postharvest conditions on broccoli microgreen antioxidant status to support the production of high‐quality produce in these systems. The relationship between nutrient formulation, harvest day, and postharvest processing was examined. Broccoli microgreens received either foliar nutrient treatment or water, were harvested at different timepoints (Days 7, 8, 9, and 10), and processed through either freeze drying alone or air frying with freeze drying. The use of water in place of the foliar nutrient treatment and later harvest day (Days 9–10) had the greatest impact on total flavonoid content (TFC, p < 0.05). Postharvest processing, air‐frying, had the greatest impact on total phenolic content (TPC) and ferric reducing antioxidant power (FRAP) for microgreens with a later harvest day ( p < 0.05). There were multiple interactions amongst the variables tested, suggesting a complex relationship between elicitors. Future work is needed to better understand these interactions to support the development of practical procedures for the growth and development of bioactive‐dense microgreens and related food products in community‐based indoor growing systems.