Abstract
Summary: 1. Proteolysis of β-casein by rennin and by pepsin was completely inhibited in the presence of 10% NaCl and was very significantly reduced by 5% NaCl. The rate of proteolysis of αs-casein was maximal in the presence of 5–10% NaCl. 2. The inhibitory effect of NaCl on the proteolysis of β-casein was independent of pH and incubation temperature. 3. The effectiveness of NaCl in controlling the development of bitter flavour in Cheddar cheese may be due to its inhibitory effect on the proteolysis of β-casein. 4. Rennin hydrolysates of β-casein were bitter in flavour whereas those of αs-casein were not.