超声处理对糯米与非糯米淀粉结构和消化性的影响

Effect of Ultrasonic Treatment on the Granular Structure and Digestibility of Waxy and Non-waxy Rice Starches

为了探究超声处理对糯米和非糯米淀粉颗粒结构和功能特征的影响,改善稻米淀粉的品质,本试验以糯稻(Y26)、非糯稻(Y9)淀粉为材料,对其进行超声处理,分析处理后淀粉的结构热力学性质及消化特性。结果表明,与对照组相比,两种淀粉经超声处理后各性质变化趋势相似,淀粉颗粒表面产生凹陷、直链淀粉含量升高、结晶度下降、傅立叶变换红外光谱(FTIR)的1 047 cm-1/1 022 cm^-1比值先增加后降低,弹性模量(G′)降低,凝胶强度减弱,糊化终止温度与起始温度之差(Tc-To)减小,快速消化淀粉(RDS)和抗性淀粉(RS)含量增加,但两种淀粉的变化程度有一定差异。本研究初步奠定了生产中根据对淀粉性质的需求来确定合适超声处理条件的理论基础。

In order to improve the quality of rice starch by ultrasonication, the effect of ultrasonication treatment on the structure and functional characteristics of waxy and non-waxy rice starch was investigated. Waxy rice(Y26) and non-waxy rice(Y9) starch were treated by ultrasound the molecular structure, thermal rheological properties and digestibility of ultrasonicated starches were analyzed. Compared with the native starches, the properties changes of the two kinds of starch were similar after ultrasonication treatment i.e. the surface of the starch granules was cracked, amylose content was increased, the degree of crystallinity decreased, the ratio of 1047 cm-1/1022 cm^-1 of the Fourier Transform Infrared Spectrum was increased first and then decreased, the elastic modulus was decreased, and the gel strength was decreased. The difference between gelatinization termination temperature and initial temperature(Tc-To) decreased, the content of rapidly digestible starch and resistant starch increased, but two starches after treatment varied different extent of the changes. After ultrasonication treatment, the strength of starch gelatinized gel decreased, and the content of resistant starch increased rapidly. This study provides preliminary experimental basis that in the production process, suitable ultrasonic treatment conditions could be determined according to the required of starch properties for different industrial applications.