市售酸奶与传统酸奶传代发酵的比较研究

【目的】为了研究酸奶中乳酸菌群在传代发酵过程中对成品酸奶的品质影响,【方法】以市售酸奶和传统酸奶在13%的脱脂乳中连续传代发酵10次,对酸奶的乳酸菌数和理化指标进行检测,对其凝乳状态、品质滋味进行分析评价。【结果】随着传代次数的增加市售酸奶和传统酸奶的乳酸菌菌落数、持水力、总酸度值均显著增加(P<0.05),pH值呈现先升高再降低的变化趋势,总体变化显著(P<0.05)；由感官评价结果可知,传统酸奶总酸度整体高于市售酸奶,所以口感上稍逊于市售酸奶,但其质地醇厚、香味浓郁而优于市售酸奶。【结论】两种酸奶中的乳酸菌群在传代过程中没有出现衰退现象,传统酸奶随着传代次数的增加,凝乳状态、风味品质都有所提升。

Comparative study on continuous subculture of market yogurt and traditional yogurt

Objective]In order to study the effect of lactic acid bacteria on the quality of finished yoghurt during the continuous subculture,Methods]yogurt sold and traditional yogurt were fermented in 13% skim milk for 10 consecutive generations.The number of lactic acid bacteria and physical and chemical indexes of yogurt were tested,and the curd state, quality and taste were evaluated.Results] with the increase of times, the number of lactic acid bacteria colonies, water holding capacity and total acidity of yogurt sold and traditional yogurt all increased significantly (P<0.05), and the pH value showed a trend of first increasing and then decreasing, and the overall change was significant (P<0.05).According to the sensory evaluation results, the total acidity of traditional yogurt is higher than that of yogurt sold, so the taste of traditional yogurt is slightly lower than that of yogurt sold,but its texture is mellow, the flavor is rich, is better than the market yogurt.Conclusion]The lactobacillus in the two kinds of yoghurt did not decline during the process, and the curd state and flavor quality of the traditional yoghurt were improved with the increase of times.