Elicitation and precursor feeding as tools for the improvement of the phenolic content and antioxidant activity of lentil sprouts

Abstract

This study considered the efficacy of UV-B treatment and precursor feeding with phenolic synthesis precursors in relation to the production of polyphenol-rich sprouts. The used modifications of sprouting caused an increase in the activities of tyrosine ammonia-lyase and phenylalanine ammonia-lyase. The biotechnological approaches used allowed for a significant enhancement of the antioxidant potential of sprouts that was strongly and positively correlated with total phenolic content. The highest increase of flavonoids content was found for the sprouts obtained with phenylalanine treatment (2.41mg/gFM, 1.6-fold with respect to the control). The highest increase in the antioxidant capacity was found for the sprouts obtained with phenylalanine (an increase of 27% after solid-liquid extraction) and combined UV-tyrosine treatments (an increase of 44% for potentially bioaccessible fractions). The results of this work may suggest the use of elicitation supported by precursor feeding as an easy and cheap tool for improving the nutraceutical potential of low-processed food.

Keywords: Antioxidant activity; Bioaccessibility; Elicitation; Phenolic overproduction; Precursor feeding; Sprouting.