Effect of refrigerated storage of milk on the manufacture and quality of Teleme cheese

Abstract

Summary Teleme cheese made from milk stored at 4–5 °C for 1–5 d and then pasteurized was compared with that made from unstored control milks. In the raw milks titratable acidity, tyrosine value and acid degree value increased more rapidly in stored milks than in the controls. With pasteurized milks, variations in coagulation times were attributable to levels of psychrotrophs in the corresponding raw milks. Differences were minor for milk fat and N content between cheeses. Curds made from milks stored > 4 d differed markedly from the controls in pH, moisture, N soluble at pH 4·6 and trichloroacetic acid (TCA)-soluble N, but only small differences in levels of casein fragments were detected. Proteolysis in mature cheese (60 d old) made from milk stored > 3 d differed significantly from the controls, and casein fragments were detectable. Off flavour related to excessive protein breakdown developed only in cheese made from milk stored > 4 d. In 60 d old cheeses there was significantly more rancidity in those made from milk stored for > 3 d than in those made from control milk. Unacceptable rancidity became evident at 60 d in cheeses produced from milk stored > 4 d. For Teleme cheesemaking psychrotrophic bacteria multiplying in the milk to levels likely to be encountered in commercial practice are of far greater importance for their lipolytic than for their proteolytic enzymes.