Abstract: In this study, the effect of addition of water-insoluble dietary fiber (IDF) enzymatically extracted from Auricularia auricula on the acidity and viable bacterial count of fermented milk was explored. One-factor-at-a-time method combined with orthogonal array design was used to optimize the formulation (concentrations of IDF, skim milk powder and sodium carboxymethyl cellulose) of fermented milk with added IDF based on sensory evaluation score. The nutrient composition and texture characteristics of the fermented milk prepared using optimized formulation were determined. The results showed that IDF from Auricularia auricula could promote the proliferation of lactic acid bacteria. The optimum formulation consisted of 7% IDF (converted into 0.78% freeze-dried powder) 1.5% sodium carboxymethylcellulose and 2.0% skim milk powder. The prepared fermented milk contained (3.53 ± 0.08)% protein, (3.12 ± 0.03)% fat, (0.78 ± 0.12)% ash, and (19.35 ± 0.49)% solids. Addition of IDF improved the water-holding capacity, hardness, chewiness and viscosity of fermented milk during storage and at the same time showed a protective effect on the starter culture.

Key words: Auricularia auricula; water-insoluble dietary fiber; fermented milk; quality evaluation

摘要： 通过酶法提取黑木耳水不溶性膳食纤维（insoluble dietary fiber，IDF），探究黑木耳IDF添加量对发酵乳酸度及活菌数的影响；以感官评分为指标，在单因素试验的基础上，通过正交试验对黑木耳IDF发酵乳的配方（黑木耳IDF、脱脂乳粉和羧甲基纤维素钠添加量）进行优化，并对优化后的黑木耳IDF发酵乳成品进行营养成分及质构特性测定。结果表明：黑木耳IDF能够促进乳酸菌增殖，黑木耳IDF添加量为7%（换算成冻干粉含量为0.78%）、羧甲基纤维素钠添加量为1.5%、脱脂乳粉添加量为2.0%时为最佳工艺，制得的黑木耳IDF发酵乳蛋白质含量为（3.53±0.08）%，脂肪含量（3.12±0.03）%，灰分含量（0.78±0.12）%，固形物含量（19.35±0.49）%；分析发酵乳贮藏期间品质发现，黑木耳IDF提高了发酵乳贮藏期间的持水力、硬度、咀嚼性和胶黏性，并且IDF对发酵剂有一定的保护作用。

关键词: 黑木耳；水不溶性膳食纤维；发酵乳；品质评价