酵母菌在发酵乳中的增殖特性及其对产品品质的影响

Proliferative Characteristics of Yeast in Fermented Milk and its Effects on Product Quality

[目的]为了探究酵母菌在发酵乳中的增殖特性及其对产品品质的影响。[方法]发酵乳中添加70~80CFU/mL酵母菌,模拟发酵乳中含有少量酵母菌,测试不同培养温度下发酵乳中酵母菌增殖特性及其对不同时间段产品组织状态、感官、酸度影响。[结果]在4~28℃测试温度范围内,温度升高会导致酵母菌在发酵乳中的延滞期缩短,增殖速度加快。酵母菌增殖过程导致产品包装鼓胀变形等,导致沙口感、发酵味等感官变化,导致酸度增长速度提高。酵母菌增殖过程未明显影响乳清析出变化及口感细腻度。[结论]在不同培养温度下,酵母菌数量及生长阶段在产品不同强度发酵味时有明显区别。产品在4℃培养时,酵母菌增殖速度极缓慢,25 d内对品质无明显影响。本研究结果为发酵乳企业提供产品质量控制技术参考。

[Objective]To explore the proliferation characteristics of yeast in fermented milk and its effect on product quality.[Method]70~80 CFU/mL of yeast was added to the fermented milk,simulating that the fermented milk contained a small amount of yeast.The proliferation characteristics of yeast in the fermented milk at different culture temperatures and its effects on the tissue state,sense and acidity of different time products were tested.[Result]The results showed that in the test temperature range of 4 to 28℃,the delay period of yeast in fermented milk was accelerated.The proliferation process of yeast bacteria leads to the swelling and deformation of product packaging,which leads to sensory changes such as sand mouth feeling and fermentation taste,and leads to the increase of acidity growth rate.The yeast proliferation process did not significantly affect the change of whey precipitation and the taste delicacy.[Conclusion]At different culture temperatures,the number and growth stage of yeast have different intensity of fermentation odor of the product.When cultured at 4℃,the yeast proliferated very slowly and had no obvious effect on quality within 25 d.The results of this study provide product quality control technology reference for fermented milk enterprises.