Abstract
The rennet curd tension test has been used to measure the influence of added whey protein, heat treatment, and added salts upon the pH and curd firmness of 3% casein sols. Heating reduced the pH of all casein sols except sols containing high levels of sodium citrate. Addition of sodium chloride, sodium citrate, tribasic sodium phosphate, and magnesium sulfate to casein sols reduced the curd tension. Heating (62.2 or 71.1 ° C. for 30 rain.) increased the curd tension of 3% casein sols containing 0.18 to 0.3% sodium chloride. Heating for 30 rain. at 62.2 ° C. increased the curd tension of casein sols containing sodium citrate or tribasie sodium phosphate. Casein sols containing whey protein plus added salts formed clots more nearly resembling a normal clot of skimmilk, an& were found to be more heat-stable when adjusted to pH 6.50 than when adjusted to 6.10. Blending. Preliminary trials suggested the following procedure for compounding the casein sols used in this study. Casein sols were prepared by weighing sufficient defrosted casein into an 8-liter beaker to make 6.3 liters of a 3% casein sol. Cold distilled water (2 ° C.