核桃风味酸乳的发酵工艺研究

Fermentation technology of walnut flavored yoghurt

以部分脱脂的核桃仁、鲜牛奶为主要原料,保加利亚乳杆菌和嗜热链球菌为发酵菌种研制核桃风味酸乳。在单因素试验的基础上,用正交试验进行发酵工艺条件的优化。结果表明:在混合乳(1∶4的核桃浆和鲜牛奶)中添加7%的白砂糖和0.4%的复合稳定剂(1∶1的羧甲基纤维素钠和藻酸丙二醇酯),再接入4%的生产发酵剂(经驯化培养的乳酸菌),42℃发酵4h,所得成品酸乳具有良好的质地和风味。

Walnut flavored yoghurt was developed using partially defatted walnut and fresh milk as main raw materials and Lactobacillus bulgaricus and Streptococcus thermophilus as bacterial starters.On basis of single factor experiment,the optimal fermentation conditions were determined by orthogonal experiment.The results suggested that when 7% sugar and 0.4% compound stabilizing agent（containing 50% CMC-Na and 50% PGA） were added into the mixed milk（walnut milk：fresh milk 1∶ 4） followed by inoculating 4% starter（domesticated lactic acid bacteria）,and the fermention was conducted at 42℃ for 4h,the yogurt would have good texture and flavour.