Whey Peptide Fractions Obtained with a Two‐Step Ultrafiltration Process: Production and Characterization

Whey protein concentrate (WPC) and heat‐treated WPC (90°C., pH 2.5, 10 min) were hydrolyzed with trypsin and chymotrypsin in an ultrafiltration reactor (PM 30). The total hydrolyzates were further fractionated (PM1) resulting in mixtures of polypeptides (M.P.) characterized by a high content of peptides larger than 5000 daltons and fractions made up of amino acids and small peptides (A.A.) rich in small components (<2000 daltons). The heat treatment of WPC modified the molecular weight profile of the fractions (M.P. and A.A.) by increasing their content in larger peptides (> 5000 daltons). Suggestions are given for possible food applications for the fractions produced.