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%w/v) 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%w/v COP were the same for the proximate composition of cassava flour from all experimental groups.