Proteolysis in Cheddar cheese: role of coagulant and starter bacteria

Abstract

Cheddar cheese was produced free of non-starter bacteria, acidified with starter or glucono-δ-lactone and containing active coagulant (chymosin or pepsin) or inactivated coagulant (pepsin). The level and type of proteolysis in the experimental cheeses was monitored by protein solubility at pH 4·6 and in 12 % TCA, polyacrylamide gel and high voltage paper electrophoresis, gel filtration and paper chromatography. The results show that the coagulant was primarily responsible for the formation of large peptides while small peptides and free amino acids were produced principally by the starter, possibly from coagulant-produced peptides.