Amylose content controls the structures and digestibility of starch-lipid complexes during microwave postprocessing
Xiaoyan Tan, Fubin Wu, Zebin Guo, Fengwei Xie, Chao Song, Xueshan Xia, Ling Guo, Yue Feng, Zhendan He
Abstract
Food postprocessing modifies the structures and properties of starch-lipid complexes, but the impact of amylose content on these changes remains unclear. In this work, starch-lipid complexes with different amylose contents (waxy corn starch: WC; normal corn starch: NC; Gelose 50: G50; and Gelose 80: G80) were prepared and the changes in structures and digestibility following microwave heat-moisture treatment (M-HMT) were investigated. Results indicated that M-HMT induced some destruction of helical structures of WC-lipid complexes, accompanied by reduced complexed lipid content, complex index, short-range molecular order, and relative crystallinity. However, for NC-lipid, G50-lipid, and G80-lipid complexes, these characteristic parameters were increased after treatment. Additionally, for the four types of treated complexes, higher amylose content led to higher values of these parameters. Notably, M-HMT endowed complexes with lower digestibility, and complexes with higher amylose content showed stronger enzyme digestion resistance. The treated G80-lipid complexes achieved the highest resistant starch content of 55.41 %. This work is expected to offer theoretical foundation and practical guidance for industrial or household production of starchy foods with a better health effect.