Sensory and physicochemical properties of biscuit produced from blends of whole wheat, soy okara and tigernut residue flours

Abstract

Biscuits are popular ready to eat, cheap and convenient food products that are consumed globally. Supplementation of wheat flour with inexpensive staples from other cereals, legumes, roots and tubers will help in improving the nutritional quality of wheat products. Therefore, this study investigated the sensory and physicochemical properties of biscuits produced from blends of whole wheat, soy okara and tigernut residue flours. The sensory qualities of the twelve whole wheat, soy okara and tigernut residue flour biscuits at p < 0.05 ranged from 5.36 to 7.68 (color), 5.60–7.64 (appearance), 4.48–7.96 (mouthfeel), 4.28–7.76 (aroma), 3.96–8.32 (taste), 3.64–8.20 (crunchiness), 3.56–7.56 (crispiness), and 5.08–8.36 (overall acceptability). Physical, proximate and mineral analysis were carried out on the best five biscuit samples containing 100:0:0 (MVP), 60:20.98:19.02 (ISP), 50.75:39.25:10 (JAR), 53.79:22.57:23.64 (GEN) and 56.32:27.39:16.29 (XEC) whole wheat, soy okara and tigernut residue flours respectively. The physical analysis showed that diameter (38.13–38.17 mm), height (37.73–37.76 mm) and thickness (6.10–6.17 mm) were not significantly different, but the weight (7.30–7.73 g), spread ratio (5.73–6.10 mm) and breaking strength (600–643 g) significantly (p < 0.05) differed among the biscuit samples. The proximate composition of the biscuits ranged from; ash (1.70–1.90%), moisture (4.00–5.70%), fiber (7.00–11.30%), fat (16.20–17.30%), protein (6.50–12.00%), carbohydrate (56.94–59.20%) while mineral content ranged from; magnesium (122.00–134.00 mg/100 g), sodium (16.00–28.00 mg/100 g), calcium (12.00–24.00 mg/100 g), iron (2.30–3.50 mg/100 g) and phosphorus (100.00–121.00 mg/100 g). The study showed that substitution of wheat flour with soy okara and tigernut residue flour at a ratio of 60:20.98:19.02 yielded the most acceptable biscuits in all the sensory attributes assessed. This implies that biscuits produced from this composite blend contain sufficient amounts of protein, fat, fiber and carbohydrate. Hence, they can serve as relief for malnutrition.