Authors: Akinoso R., J.C. Igbeka,T.M.A. Olayanju, L.K Bankole
Agricultural Engineering International: the CIGR Ejournal. Manuscript FP 05 016. Vol. VIII. October, 2006
Abstract
Moisture content , duration and temperature of roasting are some of the critical parameters influencing oil expression. Effects of these parameters on palm kernel (Elaeis guineensis Jacq.) were determined to develop model equations. A 4 x 4 x 4 factorial design was used in the test resulting in a total of 64 samples.
Each sample at moisture content 4.5, 5.9, 10.4, and 15.2 % all on wet basis (wb) and were roasted for 5, 10, 15 and 20 minutes each of which was carried out at temperatures of 70, 90, 110 and 130 oC . Data were analyzed, employing multiple regression technique to generate mathematical model. Adequacy of the model was authenticated by coefficient of determination R2 , F test and residual analysis criteria. The results obtained showed that oil yields decreased steadily with increase in moisture content . Increase in duration and temperature of roasting produced un-steady rise in oil yields . The maximum oil yield recorded was 47.0 % of the raw material equivalent to 94.7 % efficiency of oil expressed. This was achieved at kernel moisture content of 4.5 % wb, 5 minutes roasting duration and 130 oC roasting temperature. Mean oil yield was 25.8 % of the raw material. Coefficient of determination R2 at 95 % confidence level of the predictive model was 86 %, probability of prediction F, was 37.2 %. Moisture content influence is the most significant.