ABSTRACT

This study was carried out to evaluate the effect of different storage methods pit with fresh river sand/soil layer, with soil/sawdust, with moist sawdust, coated sheabutter and coated paraffin wax on the quality and physicochemical composition of the tubers of two cassava cultivars (TME 419 and UMUCASS 38) tubers. The temperature and relative humidity of the storage shed ranging from 24.02 -31.78 ^oC and 46.36 – 82.86% respectively for the five months of storage. The highest percentage weightloss was recorded by the tubers stored in moist sawdust and the least was tubers coated with paraffin wax. The least percentage spoilage was recorded on tubers stored in pit while the highest spoilage rate was recorded by tubers coated with sheabutter. The starch yield was observed to significantly (p<0.05) decreased across the storage methods and periods. The mash samples of the two cultivars had proximate composition ranging from 59.21 % - 83.73 % moisture, 0.51 % - 1.03 % ash, 1.09 % - 1.29 % crude fibre, 0.22 % - 0.39 % fat, 1.19 % - 2.08 % protein and 11.79 % - 37.36 % carbohydrate. The flour samples had proximate composition ranging from 6.48 % - 11.88 % moisture, 1.27 % - 2.11 % ash, 1.16 % - 1.52 % crude fibre, 0.57 % to 0.99 % fat, 1.42 % to 2.61 % protein and 81.61 % to 87.37 % carbohydrate. The starch, amylose, amylopectin and sugar content of the flour samples ranged from 67.71 % - 73.93 %, 15.66 % - 18.36 %, 53.09 % - 57.22 % and 3.96 % - 5.26 % respectively. There was a significant (P<0.05) difference in the mineral content of the flour samples. Data from this study show that the flour sample had low mineral content and also decreased as storage period increased. The functional properties of both cassava cultivars ranged from 0.47 g/ml - 0.75 g/ml bulk density, 1.38 g/ml -1.73 g/ml water absorption capacity, 1.37 g/ml - 1.62 g/ml oil absorption capacity, 10.62 % - 14.27 % foam capacity, pH 6.26-6.80, swelling power 10.25 % - 11.53 %, and solubility 9.57 % - 10.64 %. The hydrogen cyanide content of the mash tubers and flour samples had values ranging from 7.45 mg/kg - 22.14 mg/kg and 7.01 mg/kg - 12.88 mg/kg, respectively. The pasting properties of the flour samples were significantly (P<0.05) different and had values ranges: for peak viscosity, trough, breakdown, final and setback viscosity from 98.50 RVU - 276.33 RVU, 67.70 RVU - 245.92 RVU, 6.67 RVU - 112.67 RVU, 126.50 RVU - 391.83 RVU and 37.00 RVU - 220.33 RVU respectively. This study showed that flours from stored cassava tubers from the different storage methods showed good and acceptable qualities. The flours from the tubers stored in the pit and paraffin wax for the two cultivars show a better nutrient retention and keeping quality than the rest though all the other methods of storage were still of good quality and can be properly utilized in the food industries.