中温发酵酸乳的挥发性风味成分与感官特性的研究

Study on sensory attributes and volatile flavoured compounds of middle-temperature fermented yogurts

通过正交实验研究了球杆菌比例、全脂乳浓度、发酵终点以及蔗糖添加量对中温发酵酸乳的感官和挥发性风味成分的影响。以九个不同工艺配方为研究对象,采用描述分析感官评价法和固相微萃取结合动态顶空方法对酸乳的感官评价值和风味成分进行测定,并运用主成分分析法和偏最小二乘分析法得到感官结果和仪器测定结果的相关性。结果表明:球杆菌比例和全脂乳浓度是影响酸乳风味和挥发性风味成分的重要因素。偏最小二乘回归分析得到3种气味、3种滋味和2种余味与挥发性成分、乳酸和柠檬酸量的相关性。

The effect of different factors （including the ratio of Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgaricus, concentrations of whole milk powder, final acidity and addition of sucrose）on the sensory and volatile compounds profiles of middle-temperature fermented yoghurt was investigated according to the orthogonal statistical design test. The organoleptic quality was evaluated by descriptive sensory analysis. The flavour profile was analyzed by a SPME-GC-MS method. Relationships between flavour attributes and the volatile composition of middle-temperature fermented yogurts were determined by principle component analysis（PCA） and partial least square regression analysis（PLSR）. Results showed that the ratio of Streptococcus thermophilus and Lactobacillus delbrueckii subsp bulgaricus and concentrations of whole milk powder were major factors which influencing sensory and volatile compounds characteristics of yogurt. Using PLSR,three odour and three flavour and two aftertaste attributes were found to be correlate with subsets of volatile compounds,which including latic acid and citric acid compositional constituents.