紫山药淀粉与其抗性淀粉理化性质的比较

以紫山药淀粉为研究原料,采用不同方法分别制备压热、酶解-压热及双酶纯化抗性淀粉,分析比较了紫山药淀粉与其抗性淀粉的理化性质。试验结果表明:紫山药淀粉颗粒呈圆形或椭圆形且表面光滑;抗性淀粉颗粒破碎且呈不规则型。4种淀粉的化学结构相似,与原淀粉相比,抗性淀粉没有生成新的基团。抗性淀粉样品的凝沉速度随直链淀粉含量的增加而加快,冻融稳定性则降低;碘吸收曲线向支链淀粉吸收波长方向偏移。流变学分析表明与原淀粉相比抗性淀粉表观黏度均增大,剪切结构恢复力与抗性淀粉含量成反比。

Physicochemical Characteristics Comparison of Purple Yam Starch and Resistant Starch

The physicochemical characteristics of purple yam starch and resistant starch produced by autoclaving, enzyme-autoclaving and double enzyme purification preparation method have been analyzed and compared in the paper.The results showed that native starch granules exhibited showed oval,circular shapes with smooth surface.Resistant starch granules exhibited irregular shapes and were destroyed.Both of them were similar in chemical structure without new functional group in resistant starch granules.With the increased content of amylose,the retrogradation speed of starch samples rose gradually with reduction in freeze-thaw stability; meanwhile,absorption curve of resistant starches prepared from purple yam complexed with I shifted to amylopectin absorption wavelength.Rheological analysis showed that apparent viscosity of resistant starches were increased with the decrease in the shear restoring force compared to native starch.