Effects of phenolic acid incorporation on the structure, physicochemical properties, and 3D printing performance of rice starch gel: Exploring underlying mechanisms

Abstract

This study aimed to investigate the effects of incorporating ferulic acid (FA) or gallic acid (GA) on structural, physicochemical, and 3D printing properties of rice starch gel, while also exploring underlying mechanisms. These phenolic acids were incorporated into rice starch at varying concentrations. The addition of FA or GA reduced the gel's viscoelasticity, leading to significant decline in 3D printing accuracy. The printing accuracy of the starch decreased from 98.64 % for the native starch to 83.85 % for the FA-starch complex and 72.40 % for the GA-starch complex. Structural analysis revealed that FA and GA formed single-helical complexes with starch, disrupting the formation of a double-helical gel network and consequently reducing the gel's viscoelasticity. Additionally, the incorporation of FA and GA significantly increased the resistant starch content in the 3D-printed products, rising from 22.02 % in the native starch to 46.37 % in the FA-starch complex and 53.42 % in the GA-starch complexes. These single-helix complexes improved both the stability and bioavailability of the polyphenols. Findings of this study provide valuable insights for advancing the development of functional 3D-printed foods.

Keywords: Ferulic acid; Gallic acid; Hot-extrusion 3D printing; Rice starch.