Effect of Commercial Internal pH Control Media on Cheese Yield, Starter Culture Growth, and Activity

Abstract

Cheese manufactured with two internal pH control media, direct-to-the-vat set, and direct-to-the-vat set with an uninoculated internal pH control media were compared to determine their effect on cheese yield. Internal pH control media were inoculated with direct-to-the-vat set culture and incubated for 16h at 26°C. A complete randomized block design with nine replications of each treatment was used in the manufacture of 36 vats of cheese. Milk was analyzed for fat, total solids, total nitrogen, and non-casein nitrogen. Cheese was analyzed for fat, total solids, and total nitrogen. Whey was analyzed for fat and total nitrogen. Dry matter yield, adjusted for milk fat and casein, was greater for internal pH control media 1 than for the direct-to-the-vat set treatment. Internal pH control media 1 tended to give a higher yield than cheese manufactured with internal pH control media 2. Internal pH control media 2 treatments resulted in yields similar to the direct-to-the-vat set. Direct-to-the-vat set with uninoculated internal pH control media 2 produced curd with lower moisture content than other treatments.Growth and activity of the starter culture grown in these internal pH control media were determined and compared with skim milk as a medium. There was no difference in culture growth and activity between the organisms grown in internal pH control media. The internal pH control media produced a bulk starter that had 101.5 more colony forming units than the skim milk medium. Organisms grown in the internal pH control media were more stable after incubation than those grown in skim milk.