预糊化淀粉对糯米粉糊化、流变性能及微观结构的影响

将预糊化淀粉以不同的比例(0%～8%)分别添至糯米粉中,通过测定预糊化淀粉-糯米粉复合体系的糊化、流变特性并分析其微观结构,旨在改善糯米粉的加工及品质特性。结果表明:预糊化淀粉的添加能够显著提高糯米粉复合体系的峰值黏度、回生值、稠度系数(K)、触变回复率及弹性模量(G’),降低其损耗角正切值(tanδ),且随着添加量的增加,其凝胶结构特性变化更明显,从而证实了预糊化淀粉的添加有利于糯米粉形成稳定高的强凝胶结构。此外,预糊化淀粉的添加能够增强预糊化淀粉-糯米粉复合体系颗粒表面结构的致密性,提高其相对结晶度,从而有利于糯米粉糊形成三维网状凝胶结构,显著改善其凝胶性能。

Effect of Pregelatinized Starch on Pasting, Rheological Properites and Microstructures of Glutinous Rice Flour

In this study, pasting properties, rheological properties and microstructures of glutinous rice flour were determined in the presence of pregelatinized starch (PG) with different addition levels. Our aim was to investigate the effect of PG on the processing properties and quality of glutinous rice flour.The results showed that pregelatinized starch could significantly improve the peak viscosity, setback value, consistency coefficient, thixotropic recovery rate and storage modulus of glutinous rice flour. And with the increase of addition amount, changes on gel structure were more obvious, indicating that the addition of pregelatinized starch facilitated the formation of stable gel structure in pregelatinized starch and glutinous rice flour. Also, the microstructures showed that the addition of PG could produce glutinous rice flour with a dense surface structure and high relative crystallinity, which resulted in significantly improved gel properties.