Modelling the pasting properties of Brachystegia eurycoma (Achi) flour as influenced by sodium chloride and palm oil

Abstract

Sodium chloride and palm oil were mixed with Brachystegia eurycoma (achi) flour following the three factor three level Central Composite Rotatable Design (CCRD) in order to investigate their effects on the pasting properties of the flour and to generate model equations for predicting their interactions. The quantities of sodium chloride (common salt) and palm oil used were based on experimental design matrix of Response Surface Methodology (RSM) following a preset investigation. The pasting properties of the samples were analysed using a Rapid Visco Analyzer (RVA). The peak viscosity (PV) obtained ranged from 50 to 3679 RVU, the final viscosity ranged from 60 to 4000 RVU and the break down viscosity ranged from 8 to 1501 RVU. The statistical analysis as prescribed by the RSM showed that were significant differences (p < 0.05) among the pasting properties. The study also showed that sodium chloride and palm oil significantly affected the pasting properties of the achi flour. The regression analysis also revealed that the R² were higher than 0.75 and the lack of fits were not significant, meaning that the model adequately predicted the effects of common salt and palm oil interactions on the pasting behaviour of achi flour. The developed regression models would enable commercial food caterers to understand the effect of salt and palm oil on the rheological behaviour of achi flour and how to manipulate the quantities of sodium chloride and palm oil during soup preparation. The models would also be useful to food processors in predicting rheology of fabricated food where the ingredient mix includes sodium chloride and palm oil.

Keywords: Soup thickener, peak viscosity, pasting time, breakdown viscosity, response surface methodology