Development of highly robust selenium nanoparticles in food matrix based on polysaccharide stabilization mechanism

The rational selection of stabilizers for selenium nanoparticles (SeNPs) is hindered by a lack of mechanistic understanding. Accordingly, this study investigated the deeper polysaccharide-based stabilization mechanism by comparing the effects of linear pullulan polysaccharide (PP), branched amylopectin starch (AS), and network-soluble β-cyclodextrin polymer (SP) on the growth of SeNPs. Growth kinetics showed that bare-SeNPs and SP-SeNPs followed a reaction-limited growth pathway, yielding larger particles due to weak diffusion restriction. In contrast, PP and AS induced a diffusion-limited growth regime, effectively inhibiting Se nucleus diffusion and collision, thus forming small, uniform SeNPs. FT-IR, XPS, TGA and ITC confirmed the interaction strength between the three polysaccharides and SeNPs was AS > PP > SP, correlating with their stabilization capability. AS-SeNPs displayed the smallest size and the highest stability, maintaining high stability even under low-pH and alcohol conditions, likely due to steric hindrance. It is predicted that the shelf life of selenium-enriched Huangjiu supplemented with AS-SeNPs could reach two years. In summary, polysaccharides govern SeNPs growth primarily by restricting nucleus diffusion, supported by interfacial interactions. Steric-hindrance-based stabilizers, such as AS, are particularly suitable for complex food systems, providing a theoretical basis for rational stabilizer selection in selenium-enriched foods.