Brassica microgreens cabbage ( <i>Brassica oleracea</i> ), radish ( <i>Raphanus sativus</i> ) and rocket ( <i>Eruca vesicaria</i> ) (L.) Cav: application of red‐light emitting diodes lighting during postharvest storage and <i>in vitro</i> digestion on bioactive compounds and antioxidant activity
Manyasha L. L. Ntsoane, Vimbainashe E. Manhivi, Tinotenda Shoko, Faith Seke, Yasmina Sultanbawa, Dharini Sivakumar
Abstract
Summary Microgreens grow best under light‐emitting diodes (LED), an artificial light source. In this study, LED lights (red, blue and far‐red) were tested on brassica microgreens to see if they induced an increase in bioactive compounds (glucosinolates and phenolics). In vitro digestion also measured bioavailable bioactive compounds in the intestinal phase. LED lights (red, blue and far‐red) were applied for 6 h in storage at 5 °C and 85% RH for 5 days on cabbage ( Brassica oleracea ), radish ( Raphanus sativus ) and rocket ( Eruca vesicaria (L.) Cav). Red light significantly enhanced ascorbic acid, total phenols, kaempferol and quercetin glycoside concentrations in all three Brassica microgreens and antioxidant activities. Exposure to red LED light increased 4‐methoxyglucobrassicin (cabbage), glucoraphenin (radish), glucoraphanin A and glucoerucin (rocket). Red light stress may have resulted in secondary metabolite production in immature plants. An in vitro digestion showed higher concentrations of phenolic compounds, glucosinolate components and antioxidants in the intestinal phase. Red LED light is recommended as a postharvest treatment for improving cabbage, rocket and radish bioactive compounds.