Polyphenols content of strawberry fruit grown under Light-Emitting Diodes (LED)

• LED lights increase the synthesis of specific polyphenols in strawberries, improving nutritional value. • The response of each metabolite is specific to the type of light used. • Lighting strategies create nutritionally enhanced crops, adding value for farmers and consumers. Polyphenols are natural compounds characterized by the presence of multiple phenol rings. Dietary polyphenols have been associated with the prevention of some diseases. Strawberries are known to be a rich source of polyphenols and are widely consumed in developed countries. In the last decades various studies have been conducted to develop techniques that increase polyphenol content in fruit. However, to our knowledge, there are no previous works focusing on the quantification of specific polyphenols in strawberry fruit grown under supplementary lights. The main objective of this work was to study how manipulation of supplemental lighting can influence strawberry polyphenols. Light treatments used were far red (727 nm), red (623 nm) and blue (470 nm). HPLC–MS profiling of strawberry fruit grown under these different light regimes identified 24 polyphenols, including two flavanols, five flavonols, five hydroxybenzoic acids, one hydroxycinnamic acid and eleven anthocyanins. We observed metabolite-specific responses to supplemental lighting where red and far red light were more effective in enhancing the synthesis of some individual polyphenols. The results of the current study present an opportunity for developing nutritionally enhanced fruit crops. Additionally, implementing supplemental lighting systems enables farmers to add value to their products.