酸性乳饮料专用型黄原胶的研究与制备

Research and preparation of xanthan gum for acidified milk beverage

酸性乳饮料是近年来发展比较迅速的饮料产品,其所含酪蛋白在酸性条件下极易絮凝沉淀,因此需要添加稳定剂以防止沉淀发生。加入黄原胶能给酸性乳饮料带来良好的口感,但黄原胶无法单独稳定该体系,一般会和羧甲基纤维素钠(CMC)复配使用,不同的黄原胶产品复配后的体系稳定性能不同。通过对不同黄原胶的各项指标进行测定,找到了酸性乳饮料专用型黄原胶和普通型黄原胶的主要差异为专用型的Ca^2+质量分数约0.09%、丙酮酸质量分数约3.2%,而普通型黄原胶Ca^2+质量分数在2.0%以上、丙酮酸质量分数在4.9%以上。通过发酵体系的单因素优化,确定最佳CaCO3添加量(质量分数,以培养基质量计,下同)为0.2‰。提取过程中采用正交实验优化,在pH 3.5,温度70℃,时间4 h时获得优化后黄原胶中丙酮酸质量分数为3.12%。最后,将优化后的黄原胶加入到酸性乳饮料体系中,饮料的稳定性较好,风味和稳定性均得到了保障。

Acidified milk beverage is developing rapidly in recent years. It is important to prevent the aggregation and precipitation of casein by stabilizer under acidic conditions. As xanthan gum can t stabilize the system alone, it needs to be used with CMC together. The stability of the system varied with different xanthan gum products used. The main differences between the special and common type of xanthan gum were concentrations of Ca^2+ and pyruvic acid. The concentrations of Ca^2+ and pyruvic acid of the special type xanthan gum were about 0.09% and 3.2%, while they were 2.0% and 4.9% in the common type of xanthan gum, respectively. The optimal CaCO 3 addition was found to be 0.2‰ by single factor optimization of fermentation process. The pyruvic acid concentration of xanthan gum was 3.12% when extracted at pH 3.5, 70 ℃ for 4 h. The modified xanthan gum was used to guarantee both flavor and stability.