不同巴氏杀菌条件对酸奶品质的影响

在不同巴氏杀菌温度、时间条件下处理原料乳，以黏度、硬度、乳清析出率、pH值及感官评分为指标，研究巴氏杀菌条件对酸奶及其贮藏期间品质的影响。结果表明：原料乳杀菌在一定范围内加热温度高(高于80℃)、时间较长(大于5min)有利于提高酸奶的黏度、硬度，降低乳清析出率，稳定贮藏期间的质构、pH值及感官特征。在本实验设置的6组原料乳巴氏杀菌条件(A1：60～70℃，30min；A2：70～80℃，20min；A3：80～90℃，15min；A4：90～95℃，10min；A5：95～100℃，5min；A6：121～130℃，10s)中，样品A3和A4的酸奶黏度和凝乳硬度较高，乳清析出率低，口感风味好，且在贮藏期间能保持较好的质构和风味特征。

Effect of Different Pasteurization Conditions on Yogurt Quality

The effect of different pasteurization time-temperature conditions (A1: 60－70 ℃, 30 min; A2: 70－80 ℃, 20 min; A3: 80－90 ℃, 15 min; A4: 90－95 ℃, 10 min; A5: 95－100 ℃, 5 min; and A6: 121－130 ℃, 10 s) on the quality of freshly processed yogurt and its samples after storage at 4 ℃ was studied based on viscosity, hardness, whey separation, pH and sensory evaluation. The results showed that the thermal sterilization of raw milk at temperatures higher than 80 ℃ for more than 5 min could improve the viscosity and the hardness of yogurt, reduce its whey separation, and stabilize its texture, pH and sensory characteristics during storage. The samples resulting from A3 and A4 treatments displayed higher viscosity and hardness, lower syneresis rate and better mouth feeling and flavor, and their texture and flavor could be maintained better during 4 ℃ storage.