Isolation of Galactose-Fermenting Thermophilic Cultures and Their Use in the Manufacture of Low Browning Mozzarella Cheese

The objectives of this study were to isolate galactose-fermenting, galactosenonreleasing strains of Streptococcus and Lactobacillus and to use these strains as starter cultures in the manufacture of low browning Mozzarella cheese.Four Streptococcus isolates having the desirable phenotype, combined with a Lactobacillus helveticus strain, were acceptable as starter cultures based on activity tests.Fifteen vats of Mozzarella cheese were produced, in triplicate, representing four experimental treatments (made with galactose-nonreleasing strains) and one control (made with a galactosefermenting, galactose-releasing Streptococcus).Analyses were performed on cheese after 5 and 28 d of refrigerated storage.The lactose and galactose content of cheese remained constant or decreased over the 28-d testing period for all experimental treatments.The galactose content in the control cheese increased over the testing period and was significantly higher by d 28 than in the test cheeses.Browning was greatest on d 28 and at the more severe baking conditions.Control cheese browned more than experimental cheeses did.Melt behavior and free oil formation were generally not affected by treatment.The results indicated that the galactose-fermenting, galactose-nonreleasing strains could be used to make low browning Mozzarella cheese.