THE CHEESE-MAKING POTENTIAL OF MILK CONCENTRATED UP TO 4-FOLD BY ULTRAFILTRATION AND HEATED IN THE RANGE 90-97-DEGREES-C

Properties of interest to cheesemaking were investigated with milks concentrated by ultrafiltration and heated at 90 °C or 95–97 °C for 15 s. The effects of light homogenization before concentration and of addition of CaCl2 after heating were assessed. No changes in casein—fat or casein—whey protein interactions were detected by electron microscopy. The heat denaturation of whey protein increased linearly as the milk became more concentrated. Coagulability by rennet after heat treatment increased with concentration to close to the unheated value in 3.5 to 4-fold concentrates. The decrease in curd firming rate by heat treatment was slightly affected by concentration and addition of CaCl2 restored some of the difference. Heat treatment reduced the rate of whey loss and slightly improved the curd structure but did not affect fat losses. Light homogenization slightly reduced heat denaturation of whey protein and whey loss. © 1990, Proprietors of Journal of Dairy Research. All rights reserved.