蜡质玉米淀粉微晶的理化性质及其消化性研究

以蜡质玉米淀粉为原料,在酸醇介质中制备淀粉微晶。对制得的不同水解率的蜡质玉米淀粉微晶进行了颗粒形貌、X射线衍射、DSC热稳定性分析,溶解度和消化性能的测定。结果表明:随着酸醇水解程度的增加,淀粉颗粒形貌逐渐呈片晶状,最终为碎片;淀粉颗粒的无定形区先被水解,结晶区后被水解,进而导致颗粒破裂;晶体形态仍为A型。与原淀粉相比,淀粉微晶的Tp和Tc均增大,糊化温度范围也有很大提高;不同水解率的淀粉微晶的热焓(△H)先减小后增大。淀粉微晶的溶解度随水解率的增加不断增大。酸醇水解蜡质玉米淀粉的水解率越高,其在in vitro模型中的消化产物也就越多,消化速度也越快。对于同一水解率的淀粉微晶,其消化速度随时间的延长先上升后下降。

The Study on Physicochemical Properties and Digestibility of Waxy Corn Starch Crystallite

Waxy corn starch crystallite was prepared with acid-alcohol hydrolysis.For different hydrolysis rate of starch crystallites,the properties such as granule morphology,X-ray diffraction pattern,DSC thermostability,solubility and digestibility were studied.As the degree of acid-alcohol hydrolysis increased,starch granules gradually became lamellae and finally debris;the amorphous areas of the starch were first hydrolyzed,then defective crystal areas was hydrolyzed,and breakdown;They were A-typed starch.Compared with native starch,Tp and Tc value of starch crystallites were all raised.the range of gelatinization temperature of treated starch crystallines became larger,and gel enthalpy with different hydrolysis rate were decreased and then increased.The solubility gradually increased with increasing hydrolysis rate of starch crystallites.In vitro,the digestion products and rates increased with increasing hydrolysis rate.The digestion rates were increased first and then decreased for the same hydrolysis rate of starch crystallit.