Quality of cassava flour as affected by age at harvest, cropping system and variety

Pre-harvest operations affect the quality of food products. This study evaluated the impact of age at harvest (AH), cropping system (CS) and variety on the chemical and functional properties of high quality cassava flour (HQCF). Two white-fleshed (TMS 30572 and TMS 98/0505) and three yellow-fleshed (TMS 97/JW2, TMS 01/1371 and TMS 01/1368) cassava varieties planted either as sole crop or intercropped with maize were harvested at 12, 15 and 18 months after planting, and processed into HQCF. Chemical composition (proximate, mineral), physico-chemical properties (pH, total titratable acidity and colour) and functional properties (bulk density, water absorption index, dispersibility, swelling power, solubility index and pasting properties) of HQCF were determined. Data obtained were analysed using general linear model (GLM). AH had a significant (P < 0.05) effect on proximate and mineral composition, functional and physico-chemical properties, peak and breakdown viscosities, and peak time of HQCF. CS significantly (P < 0.05) affected the crude fibre, fat, bulk density, swelling power, mineral composition, and physico-chemical properties (except L* and b*) of HQCF. Variety significantly (P < 0.05) affected the proximate (except moisture) and mineral composition, functional properties, and breakdown viscosity of HQCF. The interactive effect of AH, CS and variety was significant (P < 0.05) on fat, dispersibility, mineral composition, and physico-chemical properties. In terms of carbohydrate content, it is desirable to harvest cassava at 12 months after planting, with TMS 98/0505 being the choice variety. Recommendation of the desirable AH, CS and variety will vary according to the desired quality of the end-products. Age at harvest is the most important single factor affecting the proximate composition and functional properties of HQCF.