Photoregulation and substrate synergy mediated biofortification of radish (Raphanus sativus L.) microgreens: A dual...

The current study investigated the effect of hydroponics and soilless media under different monochromatic light (red, blue & green) durations on the phytochemical, biochemical and antioxidant activity in radish microgreen as a sustainable controlled environment agriculture (CEA) approach. The blue light significantly enhanced total phenolic content (524.84 mg GAE/100 g), total flavonoid (75.55 mg QE/100 g), anthocyanins (18.31mg/100g), total glucosinolate (19.45μmol/g), ascorbic acid (53.78 mg/100 g), total chlorophyll (32.43 mg/100 g), chlorophyll a (25.07 mg/100 g) and chlorophyll b (11.33 mg/100 g) content up to 9th day, followed by a reduction. The antioxidant activity (94.01% DPPH inhibition and 40.51 mg/100 g FRAP inhibition) and glucosinolate content (19.45% inhibition) were the highest under hydroponic culture and blue light on the 9th day, and were standardised as the harvest maturity. The GC-MS profiling on harvest maturity revealed presence of hexadecane and eicosane as major bioactives along with 27 other compounds with significant α-amylase inhibition activity (25.16%), total fiber content (2.61 g/100 g), digestible fiber (0.23 g/100 g), non-digestible fiber (2.38 g/100 g) and protein content (1.42 g/100 g). The mineral profiling also confirmed significant amounts of various macro (N, P, K, Ca, Mg and S) and micro (Fe, Mn, Cu, Zn and B) minerals in the microgreens under hydroponic culturing. Clear grouping and positive correlation of the hydroponic culture under blue light induction was reported using PCA. These findings establish the harvest maturity of radish microgreens with enhanced functional properties of radish microgreens under blue light spectrum in hydroponic conditions as a sustainable approach with higher efficiency for nutritionally enhanced production with short growth cycle.