ISOLATION OF GALACTOSE-FERMENTING THERMOPHILIC CULTURES AND THEIR USEIN THE MANUFACTURE OF LOW BROWNING MOZZARELLA CHEESE

The objectives of this study were to isolate galactose-fermenting, gal actose-nonreleasing strains of Streptococcus and Lactobacillus and to use these strains as starter cultures in the manufacture of low browni ng Mozzarella cheese. Four Streptococcus isolates having the desirable phenotype, combined with a Lactobacillus helveticus strain, were acce ptable as starter cultures based an activity tests. Fifteen vats of Mo zzarella cheese were produced, in triplicate, representing four experi mental treatments (made with galactose-nonreleasing strains) and one c ontrol (made with a galactose-fermenting, galactose-releasing Streptoc occus). Analyses were performed on cheese after 5 and 28 d of refriger ated storage. The lactose and galactose content of cheese remained con stant or decreased over the 28-d testing period for all experimental t reatments. The galactose content in the control cheese increased over the testing period and was significantly higher by d 28 than in the te st cheeses. Browning was greatest on d 28 and at the more severe bakin g conditions. Control cheese browned more than experimental cheeses di d. Melt behavior and free oil formation were generally not affected by treatment. The results indicated that the galactose-fermenting, galac tose-nonreleasing strains could be used to make low browning Mozzarell a cheese.