Proximate composition, cyanide contents, and particle size distribution of cassava flour from cassava varieties in Zambia

Abstract

The utilisation of cassava in the food industry is on the rise in Africa. However, information about the quality traits of raw material derived from new cassava varieties is limited. Cassava flours processed from six cassava varieties (Bangweulu, Katobamputa, Mweru, Kariba, Kampolombo and Chila) were assessed for particle size distribution, dry matter, starch yields; proximate contents, cyanides and whiteness index. The variety effect was analysed. The moisture, protein, lipid, ash, and fibre contents were in the range 10.43–11.18, 1.21–1.87, 0.15–0.63, 1.21–1.78, and 0.03–0.60%, respectively. The average particle size distribution at D90 (250.44–334.34 μm) and D10 (35.56–48.52 μm) varied (p < 0.05) among varieties. The bulk and packed density ranged 0.40–0.47 and 0.62–0.67 g/cm3, respectively. Bulk density correlated positively (p < 0.05) with moisture content. The cassava root dry matter contents varied in the range 40.04–47.25%, and correlated negatively with lipid (p < 0.01), ash content (p < 0.05) and positively with fibre (p < 0.01). Starch yield ranged between 20.76 and 28.31%. The cassava cyanide contents were in the range 23.60–238.12 and 8.62–15.48 mg HCN/kg for roots and flours, respectively. The cyanide reduction was in the range 60.76–93.86%. Degrees of lightness (L*) were in the range between 93.65 and 94.55, yellowness (b*) 6.52–8.15 with greenness in the range −0.03 to 0.44. The whiteness index of flours was in the range 89.90 to 91.46. Whiteness index negatively correlated with fibre content (p < 0.01). The quality traits varied among the cassava varieties, and source of variations were due to differences in flour particle size, fibre and ash contents.