| 摘要: |
| 【目的】研究高直链玉米淀粉的理化特性，为高直链淀粉玉米新品种的培育及高直链玉米淀粉的产业化开发利用提供参考。【方法】以源自13份高直链淀粉玉米自交系和1份普通玉米自交系的籽粒为材料，研究了高直链玉米淀粉和普通玉米淀粉的淀粉粒表型特征、热特性、糊化特性、溶解度和膨胀势的差异。【结果】普通玉米淀粉中直链淀粉含量为27.72%；高直链玉米淀粉中直链淀粉含量为44.22%～78.81%，可分为Ⅳ、Ⅴ、Ⅵ、Ⅶ 4个级别。SEM结果显示，随着直链淀粉含量的增加，A型淀粉粒形态由饱满光滑、有蜡质光泽的球体或多面体变为皱缩无光泽的不规则多面体，B型淀粉粒则由饱满光滑的小球体逐渐变为无蜡质光泽的椭圆形，直至扭曲成不规则颗粒。随着直链淀粉含量的升高，初始温度（To）、峰值温度（Tp）、最终温度（Tc）、温变范围（To-Tc）逐渐升高，焓变（ΔH）则逐渐降低。普通玉米淀粉有明显的粘度峰，糊化曲线呈现出典型的“双峰”特征，高直链玉米淀粉的粘度峰随直链淀粉含量的增加逐渐消失，曲线呈“S”型。普通玉米淀粉和高直链玉米淀粉的溶解曲线和膨胀曲线都显示了相同的趋势，但溶解度和膨胀势随直链淀粉含量的增加而显著降低。【结论】与普通玉米淀粉相比，高直链玉米淀粉在淀粉粒形态、热特性、糊化特性、溶解度和膨胀势等方面都表现出了不同程度的差异，且直链淀粉含量越高差异越大。 |
| 关键词: 玉米 高直链淀粉 热特性 糊化特性 溶解度 膨胀势 |
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| 基金项目:陕西省现代农作物种业项目（K332021315）；西北农林科技大学推广专项（Z222021317） |
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| Physicochemical properties of high-amylose maize starch |
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LI Zhi-wei,ZHONG Yu-yue,WU Quan-ming,et al
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| Abstract: |
| 【Objective】High-amylose maize starch is an important industrial raw material.This study investigated its physicochemical properties to improve the cultivation of new varieties and industrial exploitation.【Method】Using thirteen high-amylose maize inbreds and one common inbred (Zheng 58),the differences in phenotypic characteristics of starch granules,thermal properties,pasting properties,solubility and expansion power of high-amylose maize starch and normal maize starch were investigated.【Result】The amylose content of common maize inbred starch was 27.72%.The amylose content of high-amylose maize inbred starch was 44.22%-78.81%,and could be divided into four levels.According to scanning electron micrographs,A-type starch granules from common inbred were full and smooth spheres or polyhedrons with waxy luster but those from high-amylose maize inbred were shrunken irregular and dull polyhedrons.There were also significant differences in B-type starch granules and full and smooth spheres gradually changed to dull ovals,even to distorted irregular shapes.With increase of amylose content,To,Tp,Tc and To-Tc gradually increased but ΔH gradually reduced.The pasting properties (RVA) of common inbred starch showed typical “doublets” curve,while that of high-amylose maize inbred starch showed “S” curve with the increase of amylose content.The melting curves and expansion curves of common inbred starch and high-amylose maize inbred starch showed same trends,while starch solubility and swelling degree decreased significantly with the increase of amylose content.【Conclusion】Compared to common corn starch,high-amylose corn starch was different in the phenotypic characteristics of starch granules,thermal properties,pasting properties,solubility and swelling power.The difference increased as the increase of amylose content. |
| Key words: maize high-amylose starch thermal property pasting properties solubility swelling power |
