In vitro digestibility, physicochemical, and sensory properties of a gluten-free biscuit from blends of cassava and African walnut flour

The study assessed the nutritional and sensory properties of a gluten-free biscuit from blends of high-quality cassava flour (HQCF) and walnut flour (WF). Design expert software was used to determine the compositing level with HQCF (minimum of 70 g and maximum of 80 g) and WF (minimum of 15 g and maximum of 30 g). Supplementation of HQCF with WF significantly influenced the water absorption capacity of the flours. Carbohydrate content (58.04–67.72%), diameter (2.98–3.70 mm), and thickness (0.54–0.79 mm) of the biscuit decreased with increasing WF substitution, while protein (7.04–10.50%), in vitro protein digestibility (16.99–18.61%), and fat (17.00–22.33%) of the biscuit samples increased with increasing levels of WF. Antinutrient content including oxalate (0.15–0.25 mg/g), phytate (0.07–0.25 mg/g), cyanide (0.03–0.11 mg/g), and tannin (0.10–0.36 mg/g) of the biscuits were within recommended safe limits. Novelty impact statement: In this study, high-quality cassava flour was composited with African walnut (Tetracarpidium conophorum) flour to increase its protein and overall nutrient composition. Consumption of biscuits from this composite flour may improve the consumption of protein-rich products and reduce prevalence of PEM. Also, this can improve the utilization of indigenous crops such as African walnut beyond their current level of usage.