Effect of predrying treatment and drying temperature on proximate composition, mineral contents, and thermophysical properties of anchote (Coccinia abyssinica (Lam.) Cogn.) flour

Anchote (Coccinia abyssinica (Lam.) Cogn.) is an indigenous underutilized but valuable root crop solely consumed in Ethiopia. It is commonly used as occasional food during holidays and as therapeutic food to treat fractured bone or develop strong bone. So far, different studies conducted related to its variety development, nutrition, and anti‐nutrition contents. In this study, attempts were made to investigate the effect of predrying treatments and drying temperature on nutritional composition and thermophysical properties of its flour. A general full factorial experiment with two factors each at three levels used to run the experiment. The proximate compositions, thermophysical properties, and mineral contents were determined using AOAC standard methods; well‐developed model equations; and atomic absorption spectrophotometry, respectively. The ranges of nutrients in mg/100 g DB were as follows: moisture content (MC) 7.37–10.10; protein 3.26–4.80; total fiber (TF) 7.24– 10.76; ether extract (EE) 0.49–0.70, ash 2.96–4.74, total carbohydrate (TC) 80.01–83.66; calcium (Ca) 357.07–482.89; magnesium (Mg) 138.87–222.38; iron (Fe) 10.87–16.00; zinc(Zn) 2.07–2.80; and copper(Cu) 1.90–2.25. The bulk density, specific heat capacity, thermal conductivity, and thermal diffusivity of the flours ranged in 0.72–0.82 (g/cm(3)), 1.710–1.780 KJ/kg°C, 0.263–0.273 W/m(2)°C, and 1.88 x 10–4– 2.12 × 10–4 m(2)/s, respectively. The predrying treatment and drying temperature significantly affected (p < .05) MC, protein, TF, EE, ash, TC, Ca, Fe, and Zn contents. The thermophysical properties were also affected by the same factors. The flour made from raw anchote dried at 100°C was better in preserving the nutrients and improving its cooking property.