胶对混浊苹果汁混浊稳定性的影响

为研究胶对混浊苹果汁混浊稳定性的影响。采用HCLP和SDS-PAGE等技术分析了果汁沉淀物的成份、沉淀物中酚类物质和蛋白质的性质,测定加了胶的果汁的黏度、Zeta电位和果汁在120d的储藏过程中浊度的变化。果汁沉淀物以蛋白质为主,还含有碳水化合物、酚类(表儿茶素、绿原酸、单宁等)、5-羟甲基糠醛(5-HMF)等VC降解产物,成分很复杂。沉淀物主要是由果汁中原有的颗粒聚集长大下沉产生。混浊苹果汁的混浊稳定性可进一步通过添加0.05%(W/V)的CMC得以改善。CMC主要是通过提高果汁的粘度和果汁中悬浮颗粒的zeta电位来改善混浊苹果汁的混浊稳定性。添加瓜尔胶主要是通过提高果汁的粘度来改善混浊苹果汁的混浊稳定性。

The Effect of Hydrocolloids on the Cloud Stability of Cloudy Apple Juice

In order to investigate the influence of hydrocolloid on the cloud stability of cloudy apple juice, the composition of sediment of juice, characterizations of poplyphenols and protein in sediment were analyzed by using HCLP, SDS-PAGE and other analysis techniques, and the viscosity of juice adding hydrocolloid, the Zeta potential of particles in juice, the turbidity changing of juice adding hydrocolloid during 120 days storage were assayed. The sediment of juice was complicated and consisted mainly of proteins, carbohydrate, phenolic compounds (epicatechin, chlorogenic acid, tannin), 5-hydroxymethyl-furaldehyde (5-HMF). The sediment mainly formed by the assembling of original particles at the beginning of storage in juice. The cloud stability of cloudy apple juice would be more improved by adding 0.05% (w/v) CMC to juice. The cloud stability of juice containing CMC was improved by increased viscosity of juice and increased Zeta potential of particles in juice, and for juice containing guar gum, it was improved by increasing viscosity of juice.