Antioxidant activity and phenolic content of germinated lentil (Lens culinaris)

Abstract

In this study, the changes in phenolic compounds and antioxidant activity of lentil seeds before and after germination were investigated. Lentil seeds were germinated in dark chambers maintained near 100% relative humidity at 20°C. Three different solvents were employed to extract the phenolic compounds present in lentil seeds and sprouts. Total content of phenolic compounds were measured by Folin-Ciocalteau method and antioxidant activity determined by two different methods: assay of hydroxyl radical scavenging activity method and oven test method. For the later method, two different concentrations of extracts (0.02 and 0.1% w/w) were added to sheep tallow and the stabilities of the treatments were determined. Peroxide value and induction period measurements were used to evaluate the in vivo antioxidant activities. The results indicated that germination modifies the quantity and quality of phenolic composition of lentil, and the solvent used for extraction influence the antioxidant activity. The evaluation of in vivo antioxidant activity of the extracts measured by delay in tallow oxidation indicated that the activity was dependent on the phenolics concentration of extract which increased when higher concentrations of the extracts were applied. These data suggested that lentil sprout flour or extract can be used as a source of natural antioxidants in functional foods.