水牛乳乳饼发酵菌种筛选及工艺优化

Single Strain Starter Screening and Process Optimization of Buffalo Dairy Cake

为研究水牛乳乳饼发酵菌种筛选及工艺优化,从自然发酵的水牛乳乳清和云南采集乳清样品中分离乳酸菌,并通过产酸、分解蛋白和脂肪能力筛选,获得一株鼠李糖乳杆菌,37℃发酵48 h可使乳清pH值从6.20降至3.60以下,乳清游离脂肪酸110.34μmol/L,蛋白水解度0.180;通过比较乳饼制作过程中原料乳的预热情况、凝乳温度、乳清pH值、添加次数等因素对乳饼得率及咀嚼力的影响,获得最佳生产工艺:原料乳加热到90℃,随后降温至70℃,分两次添加pH值3.60的发酵乳清,保温凝乳4 min,随后排除乳清,放入模型压制2 h,该工艺所制作乳饼得率高达32.500%,质地细腻,奶香浓郁,可烹饪性强。

In order to screen the fermentation bacteria and process optimization of Buffalo dairy cake,somelactic acid bacterias were isolated from naturally fermented buffalo whey and Yunnan whey samples.Lactobacillus rhamnosus RSF-1 was obtained by screening the ability of acid production,protein decomposition and fat decomposition.The pH of whey was reduced from 6.20 to below 3.60 by RSF-1 fermented at 37℃for 48 h,and the whey free fatty acid was 110.34μmol/L,the degree of protein hydrolysis was 0.180.By comparing the preheating condition of raw milk,curd temperature,whey pH,adding times and other factors in the production process of dairy cake,the effect of dairy cake yield and chewiness was obtained.The Optimum process was that raw milk was heated to 90℃and then cooled to 70℃,the fermented whey with pH 3.60 was added twice,the milk was kept at 70℃and coagulated for 4min,then the whey was removed and put the curd grains into the model for pressing for 2 h.The yield of the process was as high as 32.500%and the dairy cake has fine texture,full of milk flavor,and can be reprocessed.