Development of biscuits made with wheat, soybean and cassava flour blends using mixture design
Emeka F Okpalanma, Charles N Ishiwu, Catherine Chukwu
Composite flour was made with various blends of wheat, soybean and cassava flours to determine their nutritive potential and sensory acceptability in biscuit manufacture. Numerical optimization of the protein contents of the biscuits was performed using the response optimizer of the Design – Expert software. All the variables’ goal were set in range to generate 39 solutions at desirability of 1. The study revealed that most of all the parameters studied were significant in producing high quality biscuits. The results obtained from the contour and 3D – Surface plots for protein show that increasing the quantity of cassava in the flour blends decreases the protein contents of the biscuits. Also increasing both the soyabean and wheat contents of the flour blends increases protein content of the biscuits, with soyabean contributing more to the effect. Proximate composition ranges of the biscuit samples were; protein (2.10 - 28.50 %,) ash (0.16 -4.20 %), fibre (0.09 -0.31 %), fat (22.40 – 34.40%), carbohydrate (27.84-67.44%) and energy (463.60 – 538.70 Kcal/100g). Energy contents increases with addition of soyabean and cassava flours. Biscuit produced with composite blend 66.70 % soyabean: 16.70% wheat: 16.70% cassava contained 515.43 Kcal/100g when compared with 487.08Kcal/100g in 100% wheat. Sensory ratings revealed that biscuits containing 9.73% protein and produced from flour blend; 16.70% soybean: 66.70% wheat: 16.70% cassava were generally accepted as that of wheat biscuit.