Influence seasons of the year and somatic cell counts on physical-chemical and sensory parameters of milk and coalho cheese

ABSTRACT. The objective of this study was to evaluate the influence seasons of the year and somatic cell counts (SCC) on physical-chemical and sensory parameters of cow’s milk from individual and collective refrigeration tanks with different milking systems. In addition to analyzing the sensory acceptance of pasteurized milk and coalho cheese developed with high (> 800,000 cells mL-1) and low SCC levels (<200,000 cells mL-1). Seasonality did not affect fat content, casein, lactose, total solids, defatted dry extract and SCC, but lower protein levels than May and June were observed from July to September. Based on the SCC results, milk from refrigeration tanks was classified as low SCC and high SCC. The samples were used to obtain pasteurized milk and coalho cheese which were sensorially evaluated for general appearance, odor and flavor by a panel of untrained tasters using a hedonic scale of 9 points. Pasteurized milk with high and low SCC presented pleasant sensory characteristics to the consumer up until two days of storage. The same behavior was observed for coalho cheese at 20 and 40 days of shelf life, respectively.

摘要。本研究旨在探究年度季节与体细胞计数（Somatic Cell Counts）对采用不同挤奶系统的个体及集体冷藏罐中牛乳的理化与感官参数的影响，并分析以高（>800000个细胞·mL⁻¹）、低（<200000个细胞·mL⁻¹）体细胞计数牛乳制备的巴氏杀菌乳与科阿修干酪的感官接受度。研究结果显示，季节性对牛乳的脂肪含量、酪蛋白、乳糖、总固形物、脱脂干固形物及体细胞计数无显著影响，但7月至9月的牛乳蛋白质水平显著低于5月与6月。基于体细胞计数结果，冷藏罐中的牛乳被划分为低体细胞计数组与高体细胞计数组。以两组牛乳为原料制备巴氏杀菌乳与科阿修干酪后，采用9点快感评分量表，由未经培训的感官评价小组对样品的整体外观、气味与风味进行感官评价。结果表明，高、低体细胞计数的巴氏杀菌乳在贮藏2天内仍具备令消费者满意的感官特性；科阿修干酪则分别在货架期20天与40天时呈现出相同的感官表现。