Combined biotransformation processes affect the antioxidant, antidiabetic and protease inhibitory properties of lentils

Abstract

This work aimed to evaluate the effects of germination, enzymatic hydrolysis and their combined association on the antioxidant and antidiabetic properties and content of digestive protease inhibitor compounds of lentils. Results showed that the biotransformation of lentils positively impacted their biological activity. For antioxidant properties, the enzymatic hydrolysis of non-germinated lentils promoted an increase of 56 and 96 % in ferric reducing power and ABTS-radical scavenging, respectively, compared to the control sample (lentil extract without any treatment). Germination and enzymatic hydrolysis positively affected the antidiabetic properties of lentil extracts, reaching maximum values of 94 and 45 % for α-amylase and α-glucosidase inhibition activity, respectively. Non-germinated and hydrolyzed (NGH) lentil extracts showed an increase of 44 % in α-amylase inhibition capacity, while the combined use of germination and enzymatic hydrolysis increased α-glucosidase inhibition by 17 % compared to the control sample. The enzymatic hydrolysis, associated or not with germination, was the most adequate process to reduce the negative effects of digestive proteases, reaching minimum inhibition values of 0.01, 0.16 and 12.05 % in pepsin, trypsin and pancreatin enzymes against 20.44, 61.05 and 48.54 % for control samples, respectively. Phenolic compounds identified by UHPLC-ESI-MS/MS in lentil extracts included 3,4-dihydroxybenzoic acid, ferulic acid, rutin, coumaric acid and vanillic acid.