摘要
研究了乙醇沉淀时间对苹果果胶性质影响,乙醇沉淀5min所得果胶为组分1,沉淀5-90min所得果胶为组分2。组分1的得率、半乳糖醛酸和酯化度分别为7.72%、70.5%和80.2%,组分2相应的为1.62%、65.4%和86.5%,组分1的黏均分子质量高于组分2;组分1的总离子含量显著低于组分2,但两者的褐变指数和总多酚含量差异不显著;组分1和组分2的凝胶温度分别为90℃和86℃;组分1比组分2有更加稳定的三维网络结构。通过对2种组分0.01和0.02g/mL浓度溶液流变性质分析后发现,组分1的表观黏度、屈服应力及活化能要大于组分2。结果表明,组分1的得率、纯度、稳定性和流变学特性优于组分2。
The effect of ethanol precipitation time on the physical-chemical properties of apple pectin was studied. Two fractions of pectin obtained by ethanol precipitation were F1 for the initial 5 min and F2 for the remaining 85 min. The solid yield, galacturonic acid and degree of esterification （DE） were 7.72% , 70.5 and 80.2% in F1, and 1.62% , 65.4 and 86.5% in F2, respectively. The average viscosity molecular weight （Mw ） of F1 estimated by Mark Houwink-Sakurada equation was higher than that of F2. However, the brown index and total phenolic content had not much difference for the two fractions. The gelling temperature （ Ts） of F1 and F2 were 90 ℃ and 86 ℃ , respectively. F1 showed stronger gelling ability than F2. The apparent viscosity, yield stress and activation energy value of F1 was significantly greater than that of F2.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2009年第10期49-54,共6页
Food and Fermentation Industries
基金
农业部"948"项目--果胶产业化关键技术(No.2005-Z33)
国家"十一五"支撑计划课题--苹果果胶系列产品与优质苹果汁开发及产业化示范(2006BAD05A13)
关键词
苹果果胶
乙醇沉淀时间
半乳糖醛酸
酯化度
流变特性
apple pectin, ethanol precipitation time, galacturonic acid, degree of esterification, rheological properties
