向日葵盘天然低酯化果胶联合氯化钙制备凝固型酸奶的工艺优化

Process optimization of natural low esterification pectin from sunflower heads combined with CaCl,applied to solidified yogurt

从向日葵盘中提取获得天然的低酯化果胶(LAHP),并将LAHP与CaCl_(2),复配作为稳定剂制备凝固型酸奶。采用单因素和正交试验对酸奶的制备工艺进行优化。结果显示:LAHP主要由半乳糖醛酸(80.62%±2.44%)构成,其干燥减重、酸不溶灰分、二氧化硫及铅含量均符合国家标准的要求,平均相对分子质量为2.12×10^(5),酯化度为25.33%±1.15%。凝固型酸奶的最佳生产工艺条件为以鲜奶质量为基准,LAHP添加量0.6%、CaCl_(2),添加量0.56%、白砂糖添加量8%、发酵时间8h、发酵剂接种量0.2%、发酵温度42℃。在此条件下制备的凝固型酸奶呈乳白色,无乳清析出,口感细腻醇厚,感官评分最高,理化及微生物指标均符合国家标准的要求。

The natural low esterification pectin(LAHP)was extracted from sunflower heads,and then was combined with CaCl_(2),as stabilizer to prepare solidified yogurt.Single factor and orthogonal test were used to optimize the preparation process of solidified yogurt.The results showed that LAHP was mainly composed of galacturonic acid(80.62%±2.44%),and weight loss on drying,acid insoluble ash,sul-fur dioxide and lead contents met the requirements of national standards.The relative molecular weight was 2.12×10^(5),and the esterification degree was 25.33%±1.15%.The optimum process conditions of solidified yogurt were as follows:based on the mass of fresh milk,the addition of LAHP was O.6%,the addition of CaCl_(2),was 0.56%,the addition of sugar was 8%,the fermentation time was 8 h,the in-oculation of starter was 0.2%,and the fermentation temperature was 42℃.Undertheseconditions,the solidified yogurt was milky white without whey precipitation,tasted fine and mellow,with the highest sensory score,the physical and chemical indexes and microbial indexes were met the requirements of na-tional standards.