Changes in Total Protein Digestibility, Fractions Content and Structure During Cooking of Lentil Cultivars

Abstract

The effect of cooking on total protein digestibility and fractions content and structure of lenti l cultivars was investigated. Cooking significantly (P = 0.05) reduced the protein digestibility using pepsin and/or pancreatin. Pepsin digestibility of raw seeds ranged from 44.6 to 52.1% and that of both pepsin and pancreatin ranged from 81.8 to 99.9%. Cooking reduced the protein digestibility of the cultivars and was found to be range from 22.3 to 19.7% when pepsin was used and ranged from 77.1 to 88.2% when both pepsin and pancreatin were used. The major protein in lentil was albumin followed by globulin. Cooking significantly (P = 0.05) decreased the albumin content. The decrease was accompanied by significan t increment in the glutelin fractions. SDS-PAGE of cooked lentil protein fractions showed that lentil protein was altered quantitatively and qualitatively due to cooking. The number of subunits of total protein in lentil cultivars before cooking was found to range from 17 to 19 bands. However, after cooking they decreased and ranged from 13 to 16 bands. The effect of cooking was most pronounced in the prolamins fractions and its subunits were reduced from 4 to 2 with a higher molecular weight of 56.0kDa.