Effect of High Pressure Homogenization on the Structure and Antioxidant Properties of EGCG-OSA Corn Starch Complex

Aiming to investigate the effect of high pressure homogenization on EGCG-OSA corn starch complex, EGCG-OSA corn starch complex was prepared by heating, high pressure homogenization and high pressure homogenization followed by heating respectively. Also, Fourier infrared (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM) was utilized to characterize its structure and morphology. Rheometer and particle size analyzer was applied to analyze its rheology; and the DPPH and ABTS free radical scavenging rate was measured to compare the oxidation resistance. The research results indicated that the three kinds of complexes had high oxidation resistance, and the decline within the number of days was insignificant. Among these complexes, the one generated by sequential homogenization and heating obtained the highest oxidation resistance, and the DPPH clearance rate after 30 days still reached 89.63%, besides, the ABTS free radical scavenging rate reached 98.66%. According to the infrared and X-ray results, there was no evidence that the composite had any new chemical bonds or functional groups; the rheological results illustrated that the viscosity of the composite after high-pressure homogenization decreased more and its particle size was reduced. In summary, the complex prepared by high pressure homogenization followed by heating has higher oxidation resistance and better storage stability, which provides theoretical and experimental basis for the application of EGCG in the processing and production of starch food.