自然科学版
陕西师范大学学报(自然科学版)
食品工程与营养科
不同分子量级苹果果胶的流变性评价
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田玉霞1,乔书涛2,仇农学1*,邓红1,郭玉蓉1
(1 陕西师范大学 食品工程与营养科学学院, 陕西 西安 710062; 2 西安理工大学 机械与精密仪器工程学院, 陕西 西安 710048)
田玉霞,女,硕士研究生,研究方向为食品质量过程控制.* 通讯作者:仇农学,男,教授,博士研究生导师.E-mail: nongxueq@snnu.edu.cn.
摘要:
采用5种不同截流分子量(MWCO)的超滤膜分离苹果果胶,系统考察了浓度、温度、pH值、剪切速率、糖和盐对不同分子量苹果果胶流变学性能的影响.结果表明:苹果果胶溶液表观黏度随剪切速率的增高而逐渐降低,随浓度增大而增大,表现为典型的剪切稀化型非牛顿流体;果胶液表观黏度与其分子量成正比,与溶液温度成反比;pH值对果胶液黏度影响很大;蔗糖对苹果果胶液的黏度起促进作用,而盐会明显降低胶体溶液的表观黏度.
关键词:
苹果果胶; 流变学性能; 影响因素
收稿日期:
2009-06-02
中图分类号:
TS209
文献标识码:
A
文章编号:
1672-4291(2010)01-0104-05
基金项目:
农业部“苹果产业体系”(NYCYTX-08); 陕西师范大学优秀科技预研项目(200802020)
Doi:
Rheological properties of apple pectins with different molecular weights
TIAN Yu-xia1, QIAO Shu-tao2, QIU Nong-xue1*, DENG Hong1, GUO Yu-rong1
(1 College of Food Engineering and Nutritional Science, Shaanxi Normal University, Xi′an 710062, Shaanxi, China; 2 College of Mechanical Instrumental Engineering, Xi′an University of Technology, Xi′an 710048, Shaanxi, China)
Abstract:
Five ultrafiltration membranes in different molecular weight cut-off(MWCO) were applied to isolate apple pectin.The rheological properties and effect of concentration, shear rate, temperature, pH value, sucrose and salts on viscosity of apple pectins were studied. The results showed that apple pectin solution exhibited a shear-thinning behaviour. When the concentration of apple pectins increased, the viscosity increased too. The viscosity of apple pectins solution was in direct ratio with molecular weights and in inverse ratio with solution temperature. pH value affected the apparent viscosity of apple pectin gum remarkably. The viscosity of the pectin solutions increased in the presence of sucrose, but decreased in the presence of salts.
KeyWords:
apple pectin; rheological properties; influences factors