Effects of Traditional Moroccan Bandek Processing on Nutritional Composition, In Vitro Starch Digestibility, and Volatile Profiles of Barley and Durum Wheat Genotypes

Traditional processing can modify the nutritional and volatile characteristics of cereal-based foods. This study evaluated Moroccan Bandek production, comprising soaking, steaming, solar drying, and roasting, using three durum wheat genotypes—conventional Svevo, high-amylose Svevo HA, and soft-kernel Faridur—and the high-β-glucan hull-less barley Chifaa. Raw wholemeal flours and corresponding Bandek products were analyzed for color, protein, β-glucan, resistant starch, iron, zinc, phenolic compounds, antioxidant capacity, and volatile organic compounds (VOCs). In vitro starch hydrolysis and predicted glycemic index (pGI) were determined in Bandek products. Compared with the corresponding flours, Bandek products were darker and showed higher resistant starch, extractable phenolic compounds, antioxidant capacity, iron, and zinc concentrations, whereas protein content was lower. However, marked differences emerged among the cereal matrices. Among the durum wheats, Svevo HA Bandek had the highest resistant starch content (6.82%) and a lower pGI than conventional Svevo, whereas Faridur showed the highest pGI (74.75%). In contrast, Chifaa barley Bandek retained 6.03% β-glucan and had the lowest pGI (53.78), clearly distinguishing it from the durum wheat products. Following standardized sample preparation, total semi-quantitative VOC abundance was higher in Bandek than in flour, with pyrazines providing the clearest distinction between the processed and raw matrices and additional variation attributable to genotype. These findings demonstrate that Bandek characteristics depend strongly on the cereal species and genotype, highlighting the distinct nutritional potential of high-β-glucan barley and high-amylose durum wheat.