A Bitter Peptide from Cheddar Cheese

Abstract

A bitter peptide has been isolated from a bitter Cheddar cheese by chromatography and high voltage electrophoresis. Its molecular weight was approximately 2500 and it originated from β-casein, its N-terminus being residue 46 (glutamine) of that protein. The glutamine cyclised readily to pyrrolidone-carboxylic acid in neutral solutions of ionic strength 0.1 or less, and this change was accompanied by a loss of bitter taste.