Manipulating starch crystalline structure for controlled digestibility and glycemic response.

Postprandial hyperglycemia is a key driver in the development of type 2 diabetes, and dietary starch is a major modulator of glycemic response. The crystalline structure of starch is a principal determinant of its digestibility and postprandial glycemic response. This review synthesizes evidence establishing that the molecular packing density and stability of A-, B-, and V-type crystals often outweigh the influence of crystallinity or crystalline type alone in governing digestion resistance. We demonstrate how advanced processing techniques can precisely engineer these structural features to reduce starch digestibility. While in vitro models provide valuable mechanistic insights and animal studies elucidate underlying metabolic pathways, human trials consistently show significant individual variability in glycemic responses to crystalline transformations. This discrepancy underscores the limitation of a one-size-fits-all approach and highlights the necessity of integrating human data for meaningful predictions. Finally, we discuss the promising convergence of artificial intelligence and food structure engineering, such as 3D printing, as a transformative strategy for designing personalized low-glycemic-index foods based on tailored starch crystalline architectures. This work provides a timely synthesis to guide future research and practical applications in functional foods and diabetes management.