Interactive Effects of Chemical Pretreatment and Drying on the Physicochemical Properties of Cassava Flour Using Response Surface Methodology.

Calcium chloride and citric acid (0.6-3.4%/) were separately applied in the pretreatment of two South African cassava landraces (white and red) processed into flour at drying temperatures of 45-74°C. Optimisation using the response surface methodology showed ash (0.79-4.42%) and crude fibre (2.77-5.12%) increased as the drying temperature (DT) and concentration of pretreatment (COP) increased. Starch content (78.06-84.71%) was not influenced by the processing variables. Both pretreatments improved the lightness and whiteness index of cassava flour. Optimal processing conditions of 70°C DT and 3%/ COP were the same for the proximate composition of cassava flour from all experimental groups.