Abstract:
The use of composite flour for commercial bread baking purposes and consumption is increasingly gaining much attention in Nigeria. This study investigated and optimized the impact of baking temperature, time, moisture content and mix ratios on bread quality by mixing wheat with composite cassava-soybean flour at ratios; (100:0, 90:10, 80:20, 70:30, 60:40, and 50:50 respectively). Dough of different mix ratios were kneaded and allowed to proof at room temperature and baked at varying temperature and time in order to ascertain the optimal Thermophysical properties. Linear programming model was employed to optimize cost of resources used in baking. Sensory attributes (Taste, Aroma, Aftertaste, Mouthfeel, Crumbcolour, Crustcolour, Texture, Appearance and Overall acceptability) were evaluated, samples were significant at (P<0.05). Increase in cassava-soybean flour substitution level up to 50% wheat replacement produced acceptable bread at 63.22% acceptability. Crumb hardness and crust colour was affected with increased baking temperature and time. Decreases, however, were noted in all sensory attributes as substitution level increased. Baking was carried out at temperature range of 195 to 245oC. Analysis of variance was carried out using SPSS Software Version 16, to determine acceptance level. Central composite design was carried out using Design-Expert Software Version 8, to determine optimal baking temperature, time, moisture content, weight and volume of loaves at various mix ratios, the following results for ≤ 100g mix were deduced; 220oC, 15.06 minutes, 8.87%, 85.45g and 707.15cm3 for 90:10 mix ratio; 220oC, 16.33 minutes, 6.46%, 87.20g and 624.85cm3 for 80:20 mix ratio; 222.50oC, 17.16 minutes, 6.06%, 94.96g and 573.80cm3 for 70:30 mix ratio; 222.50oC, 17.35 minutes, 7.12%, 87.4g and 558.18cm3 for 60:40 mix ratio respectively. This study optimized relevant variables using experimental and analytical procedures. This study has shown the role of thermophysical properties in increased and sustainable food production in Nigeria.
