豆基发酵乳的制备及过程机理分析

以轴流磨工艺所制豆浆、白砂糖、乳糖、葡萄糖、乳酸菌为原料制备豆基发酵乳，工艺设计实验结果表明：豆浆1000mL、白砂糖90g、乳糖10g、葡萄糖2g、乳酸菌0．2g，42℃发酵76h，产品品质佳。该豆基发酵乳产品在4℃、24h冷藏保质期内，活菌数平均值达3．0×10^CFU／g，蛋白质3．6％，脂肪2．5％，酸度90．05。T，pH4．52，大肠菌群79个／mL，脲酶阴性，致病菌未检出，符合国标GB19302-2010《发酵乳》要求。同时，该豆基发酵乳具有新鲜、操作方便、适合商业生产应用等优点，具有广泛的商业前景。

Preparation and Process Mechanism Analysis of Fermented Soymilk

Fermented soymilk was prepared from soybean slurry obtained by axial flow grinding, white sugar, lactose and glucose. These substrates were fermented by inoculation with lactic acid bacteria. The optimum fermentation conditions were found as follows: 100 mL of soybean slurry with the addition of 90 g of white sugar, 10 g of lactose, 2 g of glucose as fermentation substrate, inoculum size 0.2 g, and fermentation at 42 ℃ for 6 h. Under these conditions, the best quality of fermented soymilk was obtained. After 24 h of storage at 4 ℃, the average viable cell count was 3.0 × 107 CFU/g with a coliform population of 79 per mL, and the protein and fat contents, acidity and pH were 3.6%, 2.5%, 90.05 °T and 4.52, respectively. Moreover, urease-negative results were obtained and no pathogenic bacteria were detected. Consequently, our fermented soymilk was in accordance with the requirements of Chinese national standards. Furthermore, the developed preparation procedure had advantages such as simple operation and good suitability for commercial applications.