Influence of particle size distribution on glycemic index value of different grains' semolina.

The glycemic index (GI) is a critical nutritional parameter that classifies carbohydrate-containing foods based on their postprandial blood glucose response. Among the various factors influencing GI, particle size distribution (PSD) of milled products has emerged as a key determinant due to its direct effect on starch digestibility and enzymatic accessibility. The present study was undertaken to investigate the influence of particle size on the glycemic index of semolina derived from a diverse range of cereal, pulse, and millet grains
Selected grains, including cereals, pulses, and minor millets, were subjected to controlled milling to obtain semolina fractions of varying particle sizes. These fractions were systematically characterized for their physical properties such as particle size distribution, density, and thousand kernel weight, along with nutritional attributes including protein and dietary fibre content. The glycemic response of different semolina fractions was evaluated using established in vitro methodologies, and the estimated glycemic index (eGI) was calculated based on starch hydrolysis kinetics
The results demonstrated a significant relationship between particle size and glycemic response. Coarser semolina fractions exhibited lower starch digestibility and reduced eGI values, attributed to decreased surface area, limited starch gelatinization, and preservation of structural integrity. In contrast, finer fractions showed higher digestibility and elevated eGI due to increased enzymatic accessibility. Variations among grain types were also observed, reflecting the combined influence of intrinsic factors such as fibre content, protein matrix, and starch composition.
The findings of this study highlight the critical role of particle size manipulation as a practical strategy for modulating the glycemic index of semolina-based food products. This approach offers significant potential for the development of low-GI functional foods, particularly for populations at risk of metabolic disorders such as diabetes and obesity. Overall, the study provides valuable insights into the interaction between milling characteristics and nutritional functionality, contributing to the advancement of health-oriented grain processing technologies.