添加豆浆对牦牛酸奶品质的影响

将不同添加量（0、20%、40%、60%）豆浆添加到牦牛乳中制备豆浆-牦牛酸奶，探讨不同添加量豆浆对牦牛酸奶理化指标、贮藏期内酸度、质构特性（硬度、稠度、黏聚性与黏性指数）、持水力、乳酸菌数和感官特性的影响。结果表明，在贮藏期内（1～14 d），随着豆浆添加量在0～60%范围内增加，牦牛酸奶酸度、持水力、质构特性、乳酸菌数均有所下降。添加20%豆浆制备的牦牛酸奶蛋白质、脂肪及非脂乳固体含量分别为3.28 g/100 g、4.58 g/100 g、8.76 g/100 g，乳酸菌数＞107 CFU/mL，感官评分为87.9分，其酸度、持水力、质构、乳酸菌数等与未添加豆浆的对照相比均无显著差异（P＞0.05）。因此，在牦牛乳中添加20%的豆浆制备豆浆-牦牛酸奶是可行的，可进一步推广应用。

Effect of soy milk addition on the quality of yak yogurt

Soy milk-yak yoghurt was prepared by adding soy milk with different additions (0, 20%, 40%, 60%), and the effects of different soy milk additions on physicochemical indexes, acidity, texture properties (hardness, consistency, cohesion and viscosity index), water holding capacity, lactic acid bacteria counts and sensory properties of yak yoghurt during storage were investigated. The results showed that during the storage period (1-14 d), the acidity, water holding capacity, texture properties and lactic acid bacteria counts of yak yoghurt decreased with the soy milk addition increased in the range of 0 to 60%. The protein, fat and non-fat milk solid contents of yak yogurt prepared by adding soy milk 20% were 3.28 g/100 g, 4.58 g/100 g and 8.76 g/100 g, respectively. The counts of lactic acid bacteria were higher than 107 CFU/ml, and the sensory score was 87.9. There were no significant differences in acidity, water holding capacity, texture and lactic acid bacteria counts (P＞0.05). Therefore, it was feasible to prepare soy milk-yak yoghurt by adding 20% soy milk in yak milk, which could be further promoted and applied.