Development of optimized substitution ratio for wheatcassava-african yam bean flour composite for Nigerian bread industries

Abstract

An optimization study of the mix ratio for substitution of Wheat flour with Cassava and African Yam Bean flours (AYB) was carried out and reported in this paper. The aim was to obtain a mix ratio that would optimise selected physical properties of the bread. Wheat flour was substituted with Cassava and African Yam Bean flours at different levels: 80% to 100% of wheat, 0% to 10% of cassava flour and 0% to 10% for AYB flour. The experiment was conducted in mixture design which was generated and analysed by Design-Expert Software 11 version. The Composite dough was prepared in different mix ratios according to the design matrix and subsequentlybaked under the same conditions and analysed for the following loaf quality attributes: Loaf Specific Volume, Bread Crumb Hardness and Crumb Colour Index as response variables. The objective functions were to maximize Loaf Specific Volume, minimize Wheat flour, Bread Crumb Hardness and Crumb Colour Index to obtain the most suitable substitution ratio acceptable to consumers. Predictive models for the response variables were developed with the coefficient of determination (R2 ) of 0.991 for Loaf Specific Volume (LSV) while that of Bread Crumb Hardness (BCH) and Crumb Colour Index (CCI) were 0.834 and 0.895 respectively at 95% confidence interval (CI).The predicted optimal substitution ratio was obtained as follows: 88% Wheat flour, 10% Cassava flour, and 2% AYB flour. At this formulation, the predicted Loaf Specific Volume was 2.11cm3 /g, Bread Crumb Hardness was 25.12N, and Crumb Colour Index was 18.88.The study shows that addition of 2% of AYB flour in the formulation would help to optimise the LSV, BCH and the CCI of the Wheat-Cassava flour bread at the mix ratio of 88:10. Application of the results of this study in bread industries will reduce the cost of bread in Nigeria, which is influenced by the rising cost of imported wheat. This is a significant development because wheat flour was the sole baking flour in Nigeria before wheat substitution initiative.
 Keywords: Bread, wheat, Cassava, African Yam Bean, Flour, Dough, Loaf Specific Volume, Crumb Hardness, Crumb Colour Index

Evaluation of baking qualities, functional and physicochemical properties of wheat supplemented with cassava and mung bean flour blends for bread making

“…The physical characteristics were measured to determine the effect of the enrichment of cassava and mung bean flour on baked loaf weight, volume, and specific volume. Loaf volume and the specific volume of bread are good parameters used to measure bread quality and the ability of the gluten to retain gas released during fermentation and proofing (Nwatu et al, 2020). Gluten develops when wheat flour is mixed with water to form a matrix that retains gas.…”

“…The bread‐baking procedure was carried out as described by Nwatu et al (2020). Bread straight dough was produced and baked at 220°C for 20 min using the recipe in Table 2 (Figure 3).…”

“…A digital weighing balance (0.01 g accuracy India) was used to measure bread weight (g). The bread loaf volume (cm 3 ) was determined using the seed displacement method as described by Nwatu et al (2020) and calculated as $$$\text{Loaf volume}({\text{cm}}^{3})=\frac{{W}_{2}\times \,{V}_{1}}{{W}_{1}},$$$ where W 1 is the weight of seeds that filled the container (g), W 2 is the weight of seeds displaced by the loaf sample (g), and V 1 is the volume capacity of the container (cm 3 ).…”

“…A digital weighing balance (0.01 g accuracy India) was used to measure bread weight (g). The bread loaf volume (cm 3 ) was determined using the seed displacement method as described by Nwatu et al (2020) and calculated as…”

“…The domestic output of wheat flour is 60,000 metric tonnes, while the rest is imported (Ibirogba, 2021). Substituting cassava flour for wheat flour could help Nigeria save some foreign exchange (Nwatu et al, 2020). Efforts geared toward technological development, evaluation, acceptance, and provision of safe alternative formulations of flour for baked products if feasible in terms of inclusion levels and physical properties will revolutionize the bakery industry and enhance food product development.…”