三种糖醇对高粱淀粉糊化特性和凝胶结构的影响

Effects of Three Sugar Alcohols on the Gelatinization Characteristics and Gel Structure of Sorghum Starch

摘要:

本文通过快速黏度分析仪（RVA）、物性测试仪（TPA）、差示扫描热量仪（DSC）、扫描电子显微镜（SEM），研究不同浓度的赤藓糖醇、木糖醇、麦芽糖醇（淀粉与糖醇比例为1:1、1:2、1:5，m/m），对高粱淀粉性质和高粱淀粉凝胶结构的影响。与原高粱淀粉相比，随着三种糖醇添加量的增加，相同温度下高粱淀粉的溶胀度下降，尤其是在75 ℃、85 ℃和95 ℃。RVA结果表明，随着糖醇添加量增加，高粱淀粉的峰值黏度和衰减值下降，然而其糊化温度增加。糖醇使高粱淀粉凝胶的硬度升高，而且随着糖醇添加量增加而增加。DSC结果表明，添加三种糖醇后，高粱淀粉的起始糊化温度，峰值糊化温度，终止糊化温度，焓变均增加，而且随着糖醇添加量增加而升高。从SEM可知，添加糖醇后的高粱淀粉凝胶的微观结构变得更紧密。

Abstract:

In this study, the effects of sugar alcohols (erythritol, xylitol, maltitol) at different concentrations (sorghum starch/sugar alcohol ratios of 1:1, 1:2, 1:5, m/m, respectively) on the characteristics and gel structure of sorghum starch were studied using rapid visco Analyzer (RVA), texture profile analyzer (TPA), differential scanning calorimetry (DSC), and scanning electron microscopy (SEM). As compared to the original sorghum starch, with increasing sugar alcohol (erythrose, xylitol, maltitol) content, the degree of sorghum starch swelling decreased, especially at 75 ℃, 85 ℃, and 95 ℃. RVA measurements revealed that peak viscosity and breakdown values of sorghum starch decreased with increasing sugar alcohol contents, while the gelatinization temperature of sorghum starch increased. The hardness of sorghum starch gel increased with increasing the addition amount of sugar alcohol. DSC measurements showed that the gelatinization onset temperature, peak gelatinization temperature, gelatinization termination temperature, and enthalpy change of sorghum starch increased with increasing sugar alcohol contents. The SEM photographs indicated that the microstructure of sorghum starch with sugar alcohol was more compact.