Functional and Nutritional Properties of Biscuits Made from Refined Wheat and Mallotus subulatus Composite Flours

Abstract

Aim: Biscuit is one of the most popular snacks, mostly produced from wheat and consumed in many parts of the world, although its production is associated with a number of challenges including the inability of wheat to thrive well in tropical regions. The study aimed at evaluating biscuits produced from blends of refined wheat and Mallotus subulatus (MS) flours. Method: Refined wheat and Mallotus subulatus (MS) flours were blended into various proportions. The flour blends [100:0 (A), 95:05 (B), 90:10 (C), 85:15 (D), 80:20 (E), 75:25 (F), 70:30 (G)] were analysed for functional and pasting properties as well as proximate composition. Biscuits produced from the flour blends were analysed for physical properties, proximate composition, mineral components and organoleptic properties. Results: The water absorption capacity for sample G was 28.00% while that of the control sample (A) was 19.00%. The bulk density ranged from 0.66 g/ml for sample A to 0.74 g/ml for sample G.  Peak and trough viscosity values decreased with the increase in addition of MS flour. The addition of MS flour caused a significant increase in the total ash, protein and fibre content of the flour blends. There was a significant increase (P=.05) in the protein, ash and fibre content of the biscuit samples with increasing addition of MS flour. The protein, ash and crude fibre of the biscuits ranged from 6.13-17.07, 3.50-5.50 and 0.98-2.73%, respectively. There was a decrease in the spread ratio of the biscuits as the substitution of MS flour increased; sample A and G had a spread ratio of 9.40 and 8.93, respectively. The values of mineral elements ranged from 23.64-46.69, 0.18-1.90, 13.41-26.72 and 56.31-82.19 mg/100g, respectively, for Mg, Fe, Ca and P. Sample D with 15% MS flour had the highest overall acceptability. Conclusion: This study highlights the potentials of Mallotus subulatus flour as a nutritionally enhancing and sustainable ingredient in bakery formulations. Partial substitution of refined wheat flour with MS flour in biscuit production will widen the scope of consumption of this underutilised legume seed, reduce dependence on wheat and increase the availability of nutritionally important nutrients in biscuits produced from refined wheat flour, which hitherto are often referred to as junks.