Physical properties of cassava mash

Summary Sorption and thermophysical properties (desorption curves, density and specific heat) of native and gelatinized cassava mash and of cassava starch were determined, in order to gain a better understanding of the heat and mass‐transfer phenomena involved in gari cooking and drying. Desorption isotherms of native cassava mash are given at four temperatures from 40 to 90°C; the experimental data were described using the GAB model with a maximum root mean square error (RMS) of 5%. The net desorption enthalpy, calculated from the desorption data, decreases from 902.0 to 80.2 kJ/kg when the moisture content increases from 0.04 to 0.24 kg of water/kg dry matter. Desorption curves are not significantly affected by the degree of gelatinization of the starch, but at constant water activity, native cassava mash has a higher equilibrium moisture content than the other samples. The density of cassava mash increases from 1239 to 1509 kg/m3 when it is dehydrated from 51.8 to 6% (wet basis), and the specific heats of dry cassava starch and dry cassava mash, determined by differential scanning calorimetry, vary linearly over the temperature range ‐20°C to 96°C from 1.128 to 1.760 and from 0.979 to 1.591 kJ/kgxK.