Development and Characterization of Low-Glycemic Couscous Enriched With β-Glucans and Proteins

Abstract

In this study, a novel functional couscous with reduced glycemic potential was developed by enrichment of traditional couscous with β-glucan and protein through the addition of hull-less barley (cv. Chifaa) and lentil flours. Couscous samples were produced using 50:50 blends of durum wheat semolina (Svevo) with Chifaa, lentil, or malted lentil flours. The cooking and textural properties, color attributes, and chemical and nutritional composition (protein, β-glucan, resistant starch, in vitro glycemic index (GI)) were evaluated in both flour blends and couscous products. The incorporation of Chifaa flour significantly improved the technological and nutritional quality of couscous, as well as its phenolic content and antioxidant capacity. Couscous containing Chifaa flour exhibited the highest water absorption, hardness, and chewiness compared to control samples. In particular, the couscous produced from the Chifaa/Lentil blend showed the highest water absorption (279.4%), total phenolic content (448.6 mg GAE/100 g), and total antioxidant capacity (416.6–470.2 mg TE/100 g), as well as the highest β-glucan and protein contents (3.57% and 22.56%, respectively). Additionally, this sample exhibited the lowest in vitro GI (50.1), meeting the criterion for classification as a low-GI food (GI < 55) and complying with FDA health claim requirements. These findings demonstrate the potential of barley–legume-based formulations to develop nutritionally enhanced couscous with improved functional and glycemic properties.