A Comprehensive Review of Synthesis and Surface Modifications of Starch Nanomaterials for Fortification of Vitamin D₃

Starch-based nanomaterials (SNPs) have garnered significant attention for their potential applications in food fortification and supplementation owing to their unique surface properties. Numerous studies have reported diverse preparation methods to produce SNPs with varying morphologies, particle sizes, stabilities, chemical reactivities, flow properties, opacities, and mechanical strengths. However, these properties, particularly in relation to micronutrient loading and release performance, remain underexplored in the current literature. Notably, the incorporation of certain micronutrients, such as vitamin D3, into SNPs often compromises particle stability and impairs release kinetics in aqueous conditions. These limitations highlight the need for optimized surface modification strategies and scalable and cost-effective encapsulation protocols. This review critically illustrates the factors influencing starch nanoparticle fabrication, characterization, surface modification, micronutrient loading, and release kinetics. We provide a comprehensive overview of the key formulation considerations, from starch selection and physicochemical properties to emerging strategies for targeted delivery applications. Additionally, the review underscores the importance of precise surface functionalization and processing techniques, including ultrasonication, lyophilization, and the degree of substitution, in enhancing micronutrient solubility and bioavailability. To our knowledge, this work offers one of the most complete syntheses of VD3 nanoencapsulation using SNPs, serving as a valuable resource for scholars in food science and nanotechnology. Furthermore, we present a detailed bibliometric analysis of the past decade, mapping research trends, identifying influential studies, and highlighting future research directions. This analysis offers insights into the impact, quality, and practical relevance of starch nanoparticle research, promoting innovation and advancement in food fortification technologies.