EVOLUTION OF THE MICROBIOLOGICAL AND BIOCHEMICAL CHARACTERISTICS OF AFUEGAL-PITU CHEESE DURING RIPENING

Changes in the microflora and biochemical characteristics of Afuega'l Pitu cheese were studied throughout a 60-d ripening period. Total viab le counts were high in milk (7.62 +/- 0.95 log(10) cfu/ml) and in chee se throughout ripening (9.26 +/- 0.56 log(10) cfu/mg in 3-d-old cheese ; 8.06 +/- 0.47 log(10) cfu/g in 60-d-old cheese). Lactic acid bacteri a were the main microbial group responsible for the substantial pH dec rease during coagulation and for the further maintenance of low pH. La ctococcus lactis ssp. Lactis, citrate-utilizing Lactococcus lactis ssp . lactis, Leuconostoc mesenteroides ssp, mesenteroides, Leuconostoc me senteroides ssp. dextranicum, Leuconostoc citreum, Leuconostoc parames enteroides, Lactobacillus plantarum, and Lactobacillus brevis were the species identified. Mean TS and the percentage of salt in the moistur e phase increased significantly during ripening to reach 72.32 and 7.5 1%, respectively, in 60-d-old cheeses. The mean fat and protein conten ts were 46.67% and 41.77% of TS, respectively. Proteolysis was weak, w ater-soluble N attained 16% of total N at the end of ripening, and pho sphotungstic acid-soluble N increased from 0.36 to 2.12% of total N du ring 60 d of ripening. The beta-CN remained relatively intact, and, co nsequently, the gamma-CN fraction did not significantly increase. Resi dual alpha(s1)-CN also remained quite high throughout ripening compare d with other varieties of traditional raw milk cheeses.