Production and Evaluation of Biscuits from Cocoyam and Soybean Flour blends

ABSTRACT

 Biscuits were produced from blends of cocoyam flour (Xanthosoma sagittfolium) and soybean flour (Glycine max). The Cocoyam and Soybean were blanched, processed into flour and used at different proportions in biscuit production. The flour samples were evaluated for proximate, functional and anti-nutritional composition. The Sensory characteristic and physical composition of the biscuits were also determined at different levels of substitution. The proximate composition of the six minutes blanched cocoyam flour (CF6),Eigh minutes blanched cocoyam flour (CFS) and blanched dehulled soybean showed varying values of 10.27 to 11.12% in their moisture contents while protein content had valying values ranging from 5.18% to 39.50%. The dehulled soybean flour had the highest fat content of 1 8.74%,then eight minutes blanched cocoyam flour (CF8) and lowest fat content was observed in six minutes blanched cocoyam flour (CF6).The highest ash content was recorded in blanched dehulled soybean flour (4.78%) while eight minutes blanched cocoyam flour (CF8) had the lowest ash content (3.28%). The carbohydrate content varied from 21.21% to 79.37%. The crude fibre of blanched dehulled soybean flour was the highest with a value of 4.66%, while CF6 had the lowest value of 1.27%. The functional properties of the flour samples showed significant differences (pamong th loose bulk density of the flour samples, while the pack bulk density ranged from 0.59% to 0.81%, the CF6 had highest value and the dehulled soybean flour with the lowest value.CF6 had the highest water absorption capacity of 3.17g/g and dehulled soybean flour with low water absorption capacity of 2.1 8g/g. The oil absorption capacity varied from 1.13 to 1.24g/g, the emulsion capacity value ranged from 18.39%to 21.67. The anti-nutritional composition of the flour sample ranged from 0.42 to 0.47% tannin, 0.19% to 0.28% oxalate, 0.58 to 0.68% phytates and 3.60% to 3.78% trypsin inhibitors.The physical properties of the biscuit sample at different levels of substitution ranged from 5.98cm to 6.04cm diameter, 17.31g to 18.lOg weight, 10.49 to 9.62% spread ratio and 2.88kg to 3.18kg break strength. The sensory evaluation shows that the biscuits increed in colour as well as the overall acceptability as the substitution increased. It can be concluded that wheat flour can be replaced with (70% cocoyam and 30% soybean) in biscuit production without affecting its sensory qualities.