Rice flour-based filled hydrogel: an effective vitamin D encapsulation system as influenced by rice flour variety

Abstract

This study investigated the effects of the physicochemical properties of filled hydrogels based on rice flour with varying amylose contents on the stability of encapsulated vitamin D₃ (VD, cholecalciferol). The filled hydrogel, prepared based on Saemimyeon with an amylose content of 25.5%, formed a gel with strong elasticity, showing the highest stability during in vitro digestion, as well as excellent pH and storage stability of the encapsulated VD. Dodamssal, which had the highest amylose content (> 40%) and gelatinization temperature, retrograded rapidly due to its high leached amylose content. This phenomenon caused gel shrinkage and subsequent emulsion leakage, resulting in a relatively lower VD retention rate after in vitro digestion compared to the Saemimyeon-based filled hydrogel. Nevertheless, compared to the emulsion system, the rice flour-based filled hydrogels formed various types of gel matrices that provided a physical barrier to the VD-containing lipid droplets, thereby significantly protecting them from the external environment.