不同糊化度马铃薯淀粉的黏度及凝胶特性分析

Viscosity and Gelling Properties of Potato Starch with Different Degrees of Gelatinization

摘要:

为探究不同糊化度马铃薯淀粉黏度及其凝胶特性的差异，本研究将马铃薯淀粉乳（料液比1:9）分别置于59 ℃和60 ℃条件下加热1、3、6、9、12、15、18 min，制备出糊化度为38.70%~91.13%的马铃薯淀粉样品。测定了不同糊化度马铃薯淀粉的黏度，微观结构，凝胶强度及弹力，并分析了马铃薯淀粉理化特性与其糊化度的相关性。结果表明，随水热处理温度升高和时间延长，马铃薯淀粉颗粒逐渐破裂，椭圆形特征形貌逐渐消失。马铃薯淀粉黏度，凝胶强度及弹力与其糊化度有显著的线性相关性（p<0.01）。随糊化度的增大，预糊化马铃薯淀粉黏度由0.17 mJ增加至3.40 mJ。未经二次加热的不同糊化度马铃薯淀粉凝胶强度和弹力随初始糊化度的增大而显著增大，但经二次加热完全糊化的马铃薯淀粉凝胶的强度和弹力随初始糊化度的增大而显著降低。不同程度的预糊化处理显著改变了马铃薯淀粉的黏度及凝胶特性。

Abstract:

In this study, potato starch dispersions (material-liquid ratio 1:9) were heated at 59 ℃ and 60 ℃for 1, 3, 6, 9, 12, 15 and 18 min, respectively, to yield starch samples with different degrees of starch gelatinization (DSG) (38.70% to 91.13%), to explore the differences in viscosity and gelation properties of these potato starch samples. The viscosity, microstructure, gel strength, and elasticity of potato starch with different DSGs were determined, and the correlation between the physicochemical properties and DSG was also analyzed. Results showed that with the increase of hydrothermal treatment temperature and time, potato starch granules were gradually ruptured, and the characteristic shape of starch granules gradually disappeared. There was a significant (p<0.01) linear correlation between potato starch viscosity, gel strength and elasticity and its DSG. The viscosity of pregelatinized potato starch increased from 0.17 mJ to 3.40 mJ with the increase of DSG. With the increase of initial DSG, the gel strength and elasticity of potato starch samples with different DSGs increased in the absence of re-heating but decreased after reheated. Different degrees of pre-gelatinization significantly changed the viscosity and gel characteristics of potato starch.