非晶颗粒态玉米淀粉理化性质及消化性能的研究

非晶颗粒态淀粉是一种特殊的淀粉物态形式，具有颗粒性，但不具有结晶性。为了实现对原淀粉颗粒的改性，本文以玉米淀粉为原料，采用乙醇溶液处理法制备非晶颗粒态淀粉。在此基础上，研究了这种非晶化处理方法对玉米淀粉的颗粒形貌、结晶性质、溶解度与膨胀力及体外消化性能的影响。结果表明，原淀粉经非晶化处理后颗粒性仍保持完整，但颗粒表面有较大爆裂孔生成，并出现明显褶皱；非晶颗粒态玉米淀粉呈现V-型衍射结构，其结晶性基本消失，颗粒由多晶颗粒态结构转变为非晶颗粒态结构；与玉米原淀粉相比，其溶解度和膨胀度在相同的测定温度下均明显增加。原淀粉经乙醇溶液处理后，其快消化淀粉含量由92.83%下降到81.64%。而慢消化淀粉和抗性淀粉总含量由7.17%上升到18.36%。因此，采用乙醇溶液处理法对淀粉颗粒进行改性将有助于开发低热量和慢血糖应答的产品。

Physicochemical Properties and Digestibility in Vitro of Non-crystalline Granular Corn Starch

Non-crystalline granular starch (NCGS) is a special structural starch, possessing granular integrity but not crystalline. In order to modify the properties of native starch granules, NCGS was prepared by ethanol solutions. Effects of non-crystalline treatment on physicochemical properties of starch, such as granular appearance, crystallinity, solubility, swelling power and in vitro digestibility were studied. The effects of this modification on rapidly digestible starch (RDS), slowly digestible starch (SDS), and resistant starch (RS) were also studied. The results showed that the granularity was kept integrated while the granules started to depress from the hilum region leading to substantial wrinkling on the surface. The treated NCGS showed V-type X-ray diffraction patterns, and its crystallinity was almost disappeared. The granules structure changed to non-crystalline. The solubility and swelling power of NCGS were increased compared with the native starch. The RDS levels of NCGS decreased from 92.83% to 81.64%, while the SDS+RS levels increased by 7.17% to 18.36%. Therefore, preparation of NCGS from aqueous ethanol treatments may be useful in the development of new products with low calorie and slow glycemic response.