Effect of period of harvest on Drying characteristics of Cowpea

Shattering loss and loss due to pest attack significantly reduce the quantity of cowpea that can be harvested from the field. This research work investigated the possibility of early harvest of cowpea, hence the main objective is to study the effect of period of harvest on drying characteristics of an improved variety cowpea (IT 97K-56S-IS. Cowpea samples were harvested at period of harvest of 60, 64, 68 and 72days and subjected to drying at 55, 65, 75, 85°C. Triplicate samples of cowpea grains of 200g were used for each drying experiment. The drying process was monitored by weighing the samples every 10mins for the first one hour; every 30mins for the next three hours and every 1hr for the next three hours till the end of drying. The data generated were applied to five drying models namely; Newton, Page, Modified page, Henderson and Pabis and Logarithmic. The models performance was tested by comparing the coefficient of determination (R2) and root mean square error (RMSE) through non linear regression analysis. The nutrients retained in the dried samples were determined by proximate analysis according to AOAC Standard and the results were subjected to analysis of variance (p<0.05)