Main Article Content

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


I.E. Nwatu
O.C. Nwajinka
A.B. Muochebe

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 subsequently
baked 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


Journal Identifiers


eISSN: 2467-8821
print ISSN: 0331-8443