Food Technology Area, Universidad de Salamanca, E.P.S de Zamora, Avda. Requejo 33, 49022, Zamora, Spain.
J Dairy Res. 2011 Aug;78(3):279-86. doi: 10.1017/S0022029911000458.
Bulk tank ewe's milks with low (<500,000 ml(-1)), medium (1,000,000-1,500,000 ml(-1)) and high (>2,500,000 ml(-1)) somatic cell counts (SCC) from three breeds were used to manufacture hard ewes'-milk cheese. Physico-chemical analysis and capillary electrophoresis of fresh cheeses and cheeses that had been ripened for 1, 2, 3 and 6 months were carried out. The results showed that high SCC levels in milk affected the moisture content of only freshly made cheeses and the pH, fat content and fat acidity of ripened cheeses. Regarding proteolysis, the levels of all β-CNs in freshly made cheeses were significantly lower as the SCC values increased and the Castellana breed was the most affected by SCC levels because a significant decrease in all α-CNs was also observed as SCC levels rose. Analysis of the casein profile by principal component analysis (PCA) revealed that there were no clear differences according the SCC up to the third month. However in the third and sixth months cheeses with low levels of SC were closely grouped and characterised by the highest levels of intact caseins. Regarding the effect of breed, the results point to a more intense proteolytic activity in the Assaf breed, whose more matured cheeses showed the highest content of casein proteolytic fragments.
从三个品种中选择体细胞计数（SCC）较低（<500,000 ml(-1))、中等（1,000,000-1,500,000 ml(-1))和较高（>2,500,000 ml(-1))的大群绵羊奶来制作硬绵羊奶酪。对新鲜奶酪和成熟 1、2、3 和 6 个月的奶酪进行了物理化学分析和毛细管电泳分析。结果表明，牛奶中 SCC 水平较高仅影响新鲜奶酪的水分含量以及成熟奶酪的 pH 值、脂肪含量和脂肪酸度。关于蛋白质水解，随着 SCC 值的增加，所有β-CN 的水平在新鲜奶酪中显著降低，Castellana 品种受 SCC 值的影响最大，因为随着 SCC 值的升高，所有α-CN 的水平也显著降低。通过主成分分析（PCA）对酪蛋白图谱进行分析表明，在前三个月，SCC 没有明显差异。然而，在第三个和第六个月，SCC 水平较低的奶酪紧密聚集，并以完整酪蛋白的含量最高为特征。关于品种的影响，结果表明 Assaf 品种的蛋白质水解活性更强，其更成熟的奶酪显示出最高含量的酪蛋白蛋白水解片段。
