Naturally occurring variations in milk pH and ionic calcium and their effects on some properties and processing characteristics of milk

Abstract

Considerable variations were found for ionic calcium and pH in milk from individual cows. Milk with lower pH tended to have a higher Ca 2+ concentration, although the relationship was weak. Milk samples with a higher Ca 2+ concentration and lower pH produced less sediment during in-container sterilisation, which was contrary to expectations. Rennet coagulation time was lower for milk with a higher Ca 2+ concentration, but curd firmness was not related to Ca 2+ concentration. There was a poor correlation between the pH reduction caused by acid addition and that resulting from increasing temperature. Sediment formation was related to pH change at high temperature. © 2012 Society of Dairy Technology.