Enhancing Nutritional Composition and Glycemic Index of Traditional Wheat Couscous Through Agglomeration With Algerian-Grown Quinoa Semolina.

Abstract

This study investigated the feasibility of replacing wheat semolina with semolina produced from Algerian-grown quinoa in making Algerian traditional couscous across substitution rates of 0%, 50%, 75%, and 100%. Couscous samples were analyzed for their proximate composition, fatty acid (GC-FID) and mineral (Inductively Coupled Plasma-Optical Emission Spectrometry [ICP-OES]) composition, cooking quality, microstructure, and in vitro glycemic index. Incorporating higher levels of quinoa (75% and 100%) into the couscous enhanced protein (13.72% ± 0.15% and 14.87% ± 0.36%, respectively) and fiber contents (1.69% ± 0.19% and 4.96% ± 1.20%, respectively) compared to wheat-based couscous (9.22% ± 0.01% and 0.32% ± 0.27%, respectively). The baseline wheat couscous values for zinc (1.49 ± 0.02 mg/100 g), iron (2.74 ± 0.09 mg/100 g), and magnesium (42.00 ± 6.22 mg/100 g) increased proportionally with substitution levels, reaching 4.63 ± 0.10, 8.09 ± 0.30, and 209.34 ± 4.74 mg/100 g, respectively, in the whole quinoa couscous formulation (p < 0.001). The long-chain omega-3 fatty acids docosahexaenoic (DHA) and eicosapentaenoic (EPA) were detected only in the 100% quinoa couscous (8.06 ± 0.01 and 22.03 ± 0.03 mg/100 g, respectively). The cooking quality of the 50% quinoa couscous was the closest to that of wheat-based couscous. The lowest glycemic index value was observed with 75% (63.04 ± 0.09) and 100% (61.26 ± 0.52) quinoa level substitution. Quinoa substitution improved the nutritional quality while maintaining relatively the culinary properties of couscous. It enhanced its health-promoting potential, supporting its use as a sustainable food, in particular for gluten-free diets