Fractionation and Taste of Peptides in Wheat Gluten Hydrolyzate by Actinase

Abstract

Wheat gluten was hydrolyzed by actinase and deamidated in 0.5 N HCL at 120t 15 min. The peptides with molecular weight 500 to 1, 000 were divided into acidic, neutral and basic fraction by ion-exchange chromatographies. Threshold values of tastes of acidic, neutral and basic fractions were 0.025, 0.025 and 0.000625%, respectively. The acidic fraction elicited sweet and slightly umami tastes. The addition of an acidic fraction into the niboshi soup stok has shown to enhance its umami and body. About 30 peptides were detetected by the fractionation of acidic fraction on HPLC using ODS column. The major constituent amino acid of them was glutamic acid.