富含纳豆激酶抹茶纳豆酸奶的发酵工艺研究

该研究以富含纳豆激酶（NK）的纳豆豆浆和复原乳为主要原料，研制富含NK的抹茶纳豆酸奶。分别探究纳豆豆浆、白砂糖、抹茶粉添加量、乳酸菌接种量对富含NK抹茶纳豆酸奶感官评分的影响，采用正交试验优化富含NK抹茶纳豆酸奶发酵工艺，并对富含NK抹茶纳豆酸奶的品质进行评价。结果表明，富含NK抹茶纳豆酸奶最适发酵工艺条件为：纳豆豆浆添加量6%，白砂糖添加量8%，抹茶粉添加量0.7%，乳酸菌接种量0.3%。在此优化条件下，酸奶的感官评分为88.6分，脂肪、蛋白质、非脂乳固体含量、酸度、NK活性及乳酸菌数分别为3.15 g/100 g、3.08 g/100 g、8.25 g/100 g、82 °T、688.6 U/mL、5.8×108 CFU/mL。其各品质指标均符合国标GB 19302—2010《发酵乳》要求，且具有一定的保健功能。

Fermentation process of matcha natto yogurt rich in nattokinase

Using natto soybean milk rich in nattokinase and reconstituted milk as the main raw materials, matcha natto yogurt rich in nattokinase was developed. The effects of natto soybean milk, sugar, and matcha powder addition and lactic acid bacteria inoculum on sensory score of the yogurt were investigated respectively. The results showed that the optimal fermentation process conditions of the yohurt were as follows: natto soybean milk addition 6%, sugar addition 8%, matcha powder addition 0.7%, and lactic acid bacteria inoculum 0.3%. Under these optimized conditions, the sensory score of yogurt was 88.6, the contents of fat, protein and non-fat milk, acidity, nattokinase activity, and lactic acid bacteria count were 3.15 g/100 g, 3.08 g/100 g, 8.25 g/100 g, 82 °T, 688.6 U/ml, and 5.8×108 CFU/ml, respectively. All the quality indexes met the requirements of GB 19302—2010 'fermented milk', and had certain health care functions.