Structural and functional superiority of high pressure processing over thermal pasteurization in oat milk: Enhancing stability, crystalline integrity, and increasing resistant starch

This study compared the multifaceted characteristics of oat milk treated by high pressure processing (HPP) and thermal pasteurization. Structural characteristics were assessed using scanning electron microscopy (SEM), laser diffraction particle size analysis, X-ray diffractometry (XRD), and Fourier-transform infrared spectroscopy (FTIR). SEM analysis revealed slight granule swelling in samples treated with HPP while maintaining intact granular morphology. HPP treatment induced a significant increase in zeta potential absolute values (p< 0.05) and enhanced relative crystallinity from 23.26% to 33.69%. Notably, XRD patterns indicated a crystalline structure transition from A-type to V-type polymorphism compared to control (CK) samples. These structural modifications correlated with reduced starch hydrolysis rates. Concurrently, HPP processing elevated resistant starch (RS) content from 19.57% to 37.41% through starch retrogradation mediated recrystallization. This investigation provided novel theoretical and technical insights for engineering nutritionally optimized oat milk products. • HPP processing preserved granular morphology while inducing structural polymorphism in oat milk. • XRD analyses confirmed a crystalline transition from A-type to V-type and enhanced crystallinity. • HPP treatment significantly reduced starch digestibility and increased resistant starch content.