Pasting Behaviour of Cassava and Maize Flour Containing Gum Arabic from Acacia senegal var. kerensis

The application of flour in food production and in the industry depends on various properties including texture and pasting. These properties of flour are influenced by their interaction with food hydrocolloids, especially gums. In the current study, the influence of replacing gum Arabic (GA) from Acacia senegal var. kerensis (Kenyan variety) at the levels of 0 %, 2%, 4%, 6% and 8% on the pasting behaviour of maize and cassava flour was investigated. Resistance to stirring was recorded as viscosity in Brabender Units (BU). Substitution of cassava and maize flour by GA reduced significantly (p < 0.05) the peak viscosity, final viscosity and setback viscosity for both flour pastes. Even though the breakdown viscosity of cassava flour pastes reduced significantly with increasing levels of the gum, maize flour pastes recorded a zero breakdown as the substitution level increased from 2 % to 8%. Pasting temperature (64.15-63.55oC) and (87.1-84.9oC) decreased with increasing gum content for cassava and maize flour pastes respectively though no significant difference was observed at lower levels and the control sample. Maize flour depicted low peak viscosity values (157 BU at 0% GA to 73 BU at 8% GA) as compared to cassava flour (645 BU at 0% GA to 384 BU at 8% GA). A significant decrease in final and setback viscosities were observed in both flour with the addition of GA. Maize flour did not however display significant difference in breakdown viscosity values as opposed to cassava flour which exhibited significant reduction in breakdown viscosity with increasing amount of gum. These results demonstrate that GA from A. senegal var. kerensis (Kenyan variety) could be considered in the preparation of various food products from cassava and maize flour to enhance binding potential, stability as well as preventing retrogradation.