Insights into light-driven dynamics of phytochemicals in sprouts and microgreens

Apart from their physiological and ecological roles, the phytochemicals are immensely beneficial for human health. However, their accumulation and biosynthesis is largely regulated by environmental factors. Among various factors, light conditions including light quality, intensity and photoperiod play an important role in phytochemical production. Sprouts/microgreens are tender immature outgrowth rich in phytochemicals as compared to their mature counterparts and are easy to produce under controlled conditions. Hence, their demand has increased throughout the globe as functional foods. Technological advancements in light-emitting diode (LED) technology have led to the controlled production of valuable sprouts that are high in nutritional content. In this review, the phytochemical profiles at sprouts stages were reviewed under artificial LED light conditions with special emphasis given to light quality. The molecular regulation under different lights is discussed with emphasis on glucosinolates (GLS), the nutritionally important phytochemicals from Brassicaceae. The induction in phytochemical accumulation is mainly photoreceptor mediated synthesis of secondary metabolites. However, the regulation and accumulation of phytochemicals under different light quality was found to be species-specific. Thus, understanding these could be an efficient strategy to improve the nutritional value of sprouts.