Pretreatments and Particle Size on the Glycemic Index and Rheological and Functional Food Properties of Bean Flours

Abstract

The beans’ protein and slow-digesting carbohydrate content make it an appealing choice for healthy food development. However, its properties are influenced by the flour extraction processes. This study is aimed at evaluating the effect of particle size and three pretreatments—drying (D), soaking+cooking+dehydrating 3 h (SCD3), and soaking+cooking+dehydrating 24 h (SCD24)—on the estimated glycemic index (eGI) compared with raw bean flour (R). The methodology covered water absorption (WAI), water solubility (WSI), amylose content, starch digestibility, eGI, phenolic quantification, and rheology. The results showed that WAI correlated negatively with WSI and amylose, varying among pretreatments and sizes. WAI increased as D<SCD24<SCD3<R. Glucose release (HI) differed between fine (125 μm) and coarse fractions (242 μm), with SCD24 and R showing the lowest eGI (22.8–24.2). SCD3 had the highest flavonoid concentration, while R and D had more quercetin-3-glucoside. SCD24 displayed higher elastic/viscous moduli than R. Bean flours from all treatments had low GI and contained bioactive polyphenols (catechin, epicatechin, ferulic acid, quercetin). The optimal treatment was SCD24, particularly in the coarse fraction, showing potential for functional food development and novel applications such as precision nutrition.