Effect of the Replacement of Corn (Zea mays) by Chickpea (Cicer arietinum) and Rice (Oryza sativa) in Extruded Snacks on Protein Digestibility, Mineral Bioaccessibility and Estimated Glycemic Index

Abstract

This study evaluated the effect of chickpea and rice incorporation to replace corn in extruded snacks on protein digestibility, mineral bioaccessibility, and estimated glycemic index (eGI) using a standardized in vitro digestion model (INFOGEST 2.0). Four formulations were analyzed: a control (100% corn, CF) and chickpea-enriched snacks (F30, F60, and the commercial flavored F60 formulation, CCP). Chickpea replacement increased protein, dietary fiber, and mineral contents while reducing total starch. Protein digestibility remained high across all samples (89.5–96.6%), although slightly lower in chickpea/rice-enriched formulations. However, these formulations provided a higher amount of digestible protein because of their increased protein content. Mineral bioaccessibility varied depending on the element, but chickpea and rice incorporation generally enhanced mineral concentrations in the fraction potentially available for absorption despite the presence of phytic acid and insoluble dietary fiber. Starch hydrolysis was rapid during the early stages of digestion, leading to high estimated glycemic index (eGI) values in all samples. Nevertheless, chickpea/rice-enriched formulations exhibited lower eGI values compared to the corn control, likely due to reduced starch content and matrix effects. Overall, chickpea and rice replacement improved the nutritional profile of extruded snacks by enhancing protein quality and mineral availability, despite its impact on glycemic response being limited, highlighting opportunities for further product optimization.