微波复合酶解改性对小米淀粉结构表征及其理化特性的影响

本文以小米淀粉为原料，采用微波、酶解、微波复合酶解三种方法改性淀粉。从淀粉颗粒形貌、偏光特性、结晶结构、短程有序性、粒径分布等方面对小米淀粉进行结构表征，测定其直链淀粉含量、溶胀力与透明度等指标以分析小米淀粉的理化特性。结果表明：改性后，小米淀粉的颗粒结构被破坏，偏光十字特性消失，结晶结构发生改变，但三种改性方法均不影响小米淀粉的基本官能团。其中，微波改性小米淀粉为A型晶体，酶解和微波复合酶解改性淀粉结晶型为B型，微波复合酶解改性淀粉的相对结晶度提高了35.32 %。改性淀粉的粒径、直链淀粉含量均有所提高，与原淀粉相比，微波复合酶解改性淀粉的直链淀粉含量增加了49.03 %。综上所述，与单一法相比，微波复合酶解法对淀粉颗粒结构和理化性质的改善效果最佳，这对于小米淀粉基食品的开发应用具有重要意义。

Effect of microwave complex enzymatic digestion on the structural and physicochemical properties of millet starch

In this study, millet starch was used as raw material to modify starch by three methods: microwave, enzymatic digestion and microwave complex enzymatic digestion. The structural characterization of millet starch was carried out in terms of starch granule morphology, polarization characteristics, crystalline structure, short-range orderliness and particle size distribution, and the indexes of straight-chain starch content, swelling power and transparency were measured to analyze the physicochemical properties of millet starch. The results showed that after modification, the granular structure of millet starch was destroyed, the polarized cross characteristics disappeared and the crystalline structure was changed, but all three modification methods did not affect the basic functional groups of millet starch. Among them, microwave modified millet starch was crystalline type A, enzymatic and microwave complex enzymatic modified starch was crystalline type B. The relative crystallinity of microwave complex enzymatic modified starch was increased by 35.32 %. The particle size and straight-chain starch content of modified starch were increased, and the straight-chain starch content of microwave complex enzymatic modified starch increased by 49.03 % compared with the original starch. In summary, compared with the single method, the microwave complex enzymatic digestion method has the best effect on improving the structure and physicochemical properties of starch granules, which is important for the development and application of millet starch-based foods.