Development, Nutrient Composition and Sensory Properties of Biscuits Produced from Composite Flour of Wheat and African Yam Bean

Abstract

The aim of the study was to improve the protein content of biscuit; a low protein but widely consumed snack by school-aged children. The study was carried out at the Department of Crop Utilization; International Institute of Tropical Agriculture (IITA), Ibadan between March, 2012 and December, 2012. Composite flour was produced from African yam bean (a nutrient-dense but underutilized legume) flour (AYBF) and wheat flour (WF).The composite flour was prepared at various ratios WF/AYBF 100:0, 80:20, 70:30 and 60:40.and used to produce biscuits. These biscuits samples were analysed and the 100/0 WF: AYBF biscuit served as control. Proximate analysis, crispness (breaking force) and sensory evaluation of the biscuit samples were determined using standard methods. Proximate analysis showed significant increase (P=.05) in protein (9.61-14.71%), ash (1.37-2.42%) and sugar (14.11-21.29%) and significant decrease in starch (76.66-51.15%) and fat (12.53-8.13%) contents with increase in AYBF in the biscuits. There was no significant difference in the moisture contents of the test samples. Crispness of the biscuit increased with increase in percentage of AYBF in the flour blend. The breaking force values reduced from 8.5kg (for 100/0 WF: AYBF biscuits) to 3.0kg (60/40 WF: AYBF biscuits). Lower breaking force was found to correspond with higher crispness. Sensory evaluation results showed that all biscuit samples had high rating for all evaluated attributes. The closeness of values obtained for all biscuit samples to the control sample indicate a high level of acceptance of the AYBF-WF biscuits. Hence, suggesting a way of obtaining biscuits with higher protein content.