稳定剂对搅拌型酸奶品质特性的影响

Effect of stabilizer on quality characteristics of stirred yogurt

以果胶、羧甲基纤维素钠(CMC-Na)和瓜尔豆胶为稳定剂,YF-L812为发酵剂,通过酸度、黏度和持水力分析稳定剂对搅拌型酸奶品质的影响,采用响应面法优化稳定剂的添加量与酸奶黏度的线性关系。结果表明:发酵刚开始的2 h,稳定剂对乳酸菌的产酸速度有明显的抑制作用(P<0.01),但随着发酵时间的延长这种抑制作用越来越弱,稳定剂对酸奶生产的速度不会产生明显影响。与对照组相比CMC-Na和果胶对酸奶黏度的影响差异显著(P<0.01),用量0.15%的瓜尔豆胶与对照组黏度值始终无显著差异(P<0.01)。0.15、0.20、0.25%三种不同浓度的果胶均能有效提高酸奶的持水力,浓度越高效果越好。CMC-Na只有当添加的量达到0.25%时可使酸奶持水力达到较好的效果,而瓜尔豆胶对酸奶持水力影响不明显。响应面分析结果表明,回归方程模型极显著,用此模型预测稳定剂添加量与黏度的关系可行。

Using pectin, sodium carboxymethyl cellulose(CMC-Na) and guar gum as stabilizers and yf-l812 as starter, the effects of stabilizers on the quality of stirred yoghurt were analyzed by acidity, viscosity and hold water analysis. Response surface method was used to optimize the linear relationship between the amount of stabilizer added and the viscosity of yogurt. The results showed that the stabilizer had a significant inhibitory effect on the acid production rate of Lactic acid bacteria in the first 2 hours of fermentation(p<0.01), but the inhibitory effect became weaker and weaker with the extension of fermentation time, and the stabilizer had no significant effect on the production speed of yogurt. Compared with the control group, the influence of CMC-Na and pectin on the viscosity of yogurt was significantly different(p<0.01),and the viscosity value of guar gum with the dosage of 0.15% was always not significantly different from that of the control group(p<0.01),0.15, 0.20 and 0.25% the three different concentrations of pectin can effectively improve the holding water of yogurt. The higher the concentration, the better the effect. CMC-Na can improve water holding capacity of yogurt only when the added amount reaches 0.25%, while guar gum has no obvious effect on water holding capacity of yogurt. The response surface analysis results show that the regression equation model is very significant, and it is feasible to predict the relationship between the amount of stabilizer added and the viscosity with this model.