摘要
以甘薯渣为原料制备果胶,采用高效离子交换色谱测定果胶单糖构成,滴定法测定果胶酯化度(DE),并利用扫描电镜对果胶粉及果胶凝胶显微结构进行观察,进而探讨了温度、pH值、剪切速率、Ca2+浓度对果胶溶液黏度的影响。结果表明:果胶单糖含量高低顺序为半乳糖醛酸(79.23%)>半乳糖(9.48%)>鼠李糖(7.38%)>葡萄糖醛酸(3.76%)>木糖(3.74%)>葡萄糖(1.47%)>阿拉伯糖(1.23%),DE为31.71%。甘薯果胶粉呈不规则片状,而其凝胶则具有多孔网状结构。随着温度升高,果胶溶液黏度均呈下降趋势;pH值对黏度的影响较大,pH值5.0和9.0时,果胶溶液黏度最高,分别为3.82mP.s和3.65mP.s;随着剪切速率增大果胶溶液黏度迅速降低后趋于稳定;Ca2+能显著提高果胶溶液黏度,且在0～50 mmol/L内,Ca2+浓度与果胶溶液黏度值间存在一定正相关。
Pectin was extracted from sweet potato residues. Sugar composition and degree of esterification （DE） of pectin were determined by high performance anion exchange chromatography and titration method respectively. Microstructure of pectin powder and pectin gel was observed by scanning electron microscope. The effect of temperature, pH, shear rate and Ca2＋ concentration on viscosity of pectin solution were also investigated. The results showed that The order of sugar composition in sweet potato pectin was galacturonic acid （79.23 % ） 〉 galactose （9.48 % ） 〉 rhamnose （7.38%） 〉 glucuronic acid （3.76%） 〉 xylose （3.74%） 〉glucose （1.47%） 〉 arabinose （1.23%）, DE was 31.71%. The microstructure of pectin powder was irregular flake-like, whereas the pectin gel had a porous network form. The viscosity of pectin solution decreased when the temperature was increasing; pH affected viscosity obviously, pectin solution had higher viscosity at the pH 5.0 and 9.0, and the value were 3.82mP · s and 3.65mP · s respectively. With increasing the shear rate, viscosity decreased rapidly, and then trended to steady; Ca2＋ could improve the viscosity of pectin solution remarkably, in the extent of 0 ~ 50 mmol/L, there was positive relationship between Ca2＋ concentration and viscosity of pectin solution.
出处
《食品与发酵工业》
CAS
CSCD
北大核心
2010年第8期74-78,共5页
Food and Fermentation Industries
基金
现代甘薯农业技术体系建设专项(nycytx-16-B-16)
关键词
甘薯果胶
单糖构成
醣化度
黏度特性
sweet potato pectin, sugar composition, degree of esterification, viscosity properties
