Effects of proteins on the structure, physicochemical properties, and in vitro digestibility of wheat starch-lauric acid complexes under various cooking methods

Abstract

Herein, we investigated the effects of gluten proteins (Pr) on the structure, physicochemical properties, and in vitro digestibility of wheat starch-lauric acid (WS-LA) complexes under various cooking methods (steaming, boiling, and baking). There was no ternary complex formation between WS, LA, and Pr in the samples after different cooking methods. Scanning electron microscopy (SEM) and fluorescence microscopy showed variation in size, structure and distribution of WS-LA of WS-LA-Pr samples after cooking. An increase in the intensity of V-type diffraction peak and thermal stability was observed in steamed and baked samples, however, opposite trend was noticed in boiled sample. Additionally, a higher 1022/995 cm−1 absorbance ratio was noted in WS-LA-Pr sample treated with boiling than other cooking methods. Further, in vitro resistance to enzymatic hydrolysis was improved in samples treated with steaming and baking compared with boiled treated samples. In sum, this study may offer a thorough understanding on how these interactions take place during food processing, to optimize the production and development of new food products with desired microstructure and functionality features.