复配稳定剂稳定芒果酸奶凝乳结构的作用机理

Mechanism of compound stabilizer stabilizing curd structure of mango yogurt

为了探讨复配稳定剂对芒果酸奶凝乳结构及其稳定性的作用,本试验对以乙酰化二淀粉己二酸酯(ADA)、瓜尔豆胶、海藻酸丙二醇酯(PGA)为复配稳定剂的搅拌型芒果酸奶的感官品质、质构、组织结构进行了研究。采用L9(34)正交表,调整3种稳定剂的配比,测定其感官分值和持水力,并通过仪器分析方法测定了酸奶的质构和微观结构。结果表明:当ADA、瓜尔豆胶和PGA的添加量分别为0.2%、0.008%、0.03%时,能最大程度地改善芒果酸奶的品质,感官分值达到最高,显著高于(P<0.05)空白组9.3%。复配稳定剂的添加不影响酸奶的滴定酸度和pH值,但显著(P<0.05)提高了芒果酸奶的持水力,并改善了其黏度和硬度。扫描电镜图显示,添加复配稳定剂后,瓜尔豆胶与蛋白质相互结合形成网络结构,变性淀粉嵌于网络中间,稳定了芒果酸奶的凝乳结构,改善了芒果酸奶的感官品质。复配稳定剂能有效地作用于芒果酸奶,这为解决热带亚热带水果酸奶生产过程中普遍存在的稳定性问题提供了参考依据。

To explore the effects of compound stabilizer on the structure and stability of mango yogurt curd,the sensory quality,texture and structure of the stirred mango yogurt containing a stabilizer mixture of acetylated distarch adipate(ADA),guar gum and propylene glycol alginate(PGA)were assessed.The sensory score and water holding capacity(WHC)of the yogurt containing three stabilizers at varying blending ratios were determined using L9(34)orthogonal array.The texture and microstructure of yogurt were measured by using instrumental analysis methods.The results showed that adding ADA,guar gum and PGA at an amount of 0.2%,0.008%,0.03%,respectively,could optimally improve yogurt quality and achieve the highest sensory score,with 9.3%(P<0.05)higher than the blank group,of mango yogurt.The addition of the stabilizer mixture showed no effect on the titratable acidity and pH value of yogurt,but significantly(P<0.05)increased its water holding capacity and improved its viscosity and hardness.The scanning electron micrograph indicated that guar gum and protein combined to form a network structure after adding compound stabilizers,and modified starch was embedded in the middle of the network,which stabilized the curd structure of mango yogurt,and improved the sensory quality of mango yogurt.The compound stabilizer can effectively act on mango yoghurt,and this can provide a reference for solving the common stability problems in the production of tropical and subtropical fruit yoghurt.