响应面分析法优化干酪凝乳工艺的研究

OPTIMIZATION OF THE COAGULATION PROCESS OF CHEESE BY RESPONSE SURFACE METHODOLOGY

在单因素试验的基础上，利用响应面分析法对干酪凝乳条件进行优化，并应用正交试验研究影响乳清中干物质含量的因素．通过SAS软件得到优化工艺：发酵剂添加量2％、氯化钙添加量0．02％、凝乳温度32℃时，凝乳时间最短；凝块切割边长1．5cm、热烫温度37℃、热烫时间10min时，乳清中干物质含量最低．按照优化工艺参数进行验证试验，干酪凝乳时间为5．17min，乳清中干物质含量为5．51％，干酪产率达到13．11％，与模型预测值基本相符，干酪产率比同类产品提高1％～2％．

Based on single factor experiments, the response surface methodology （RSM） was. used to optimize the coagulation process of cheese. The orthogonal experimental design method was applied to study the factors influencing the content of dry matter in whey. Based on the SAS software, the optimization results show that the shortest coagulation time is obtained under the conditions of inoculum 2% （ the ratio of Lactobacillus bul- garicus to Streptococcus thermophilus is equal to 1 ： 1 ） , CaCl2 amount 0.02% and coagulation temperate 32 ℃ ; and that the dry matter in the whey has the lowest content under the conditions of cutting size of the curd 1.5 cm3, cooking temperature 37 ℃ and cooking time 10 min. The results of confirmatory experiment under the optimized parameters show that the coagulation time is 5.17 min, the content of dry matter is 5.51%, and the yield of cheese curd reaches 13.11% , which basically agree with the value of the prediction model. The yield of the cheese is higher than the similar products by 1% to 2%.