All rights reserved This work by Wilolud Journals is licensed under a Creative Commons Attribution 3.0 Unported License 36 Continental J. Engineering Sciences 9 (1): 36 - 49, 2014 ISSN: 2141 – 4068 © Wilolud Journals, 2014 http://www.wiloludjournal.com Printed in Nigeria doi:10.5707/cjengsci.2014.9.1.36.49 EFFECT OF VARIETY AND PROCESSING PARAMETERS ON OIL CONTENT AND OIL PROPERTIES OF CASTOR SEEDS * F. A. Oluwole 1 , N. A. Aviara 2 , B. Umar 2 and H. Umar 3 . 1 Department of Mechanical Engineering, University of Maiduguri, Maiduguri, Nigeria 2 Department of Agricultural and Environmental Resources Engineering, University of Maiduguri, Maiduguri, Nigeria, 3 Department of Chemical Engineering, University of Maiduguri, Maiduguri, Nigeria ABSTRACT This paper carried out experimental studies on determination of oil content of four varieties of castor seeds available in North Eastern Nigeria, namely: White Big Size (WBS), Black Big Size (BBS), Grey Medium Size (GMS) and Grey Small Size (GSS). Methanol was used as solvent for the extraction process. Mass of oil extracted from the four varieties revealed that the GMS gave the highest oil content of 54.5% followed by the GSS of 40.17%. The WBS gave oil content of 35.5% and the least of 29.67% was observed from the BBS. The results of the statistical analysis shows that the observed differences between means of the oil content from these four castor seeds are significant at 5% level. The characterization analysis showed that the tested parameters, which include specific gravity, refractive index, acid value, iodine value, saponification value, viscosity were within the ASTM standard specifications. KEYWORDS: Castor seed, soxhlet extractor, methanol, extraction, characterization, model equation Received for Publication: 14/10/14 Accepted for Publication: 07/12/14 Corresponding Author: engrfasiu@yahoo.com INTRODUCTION Castor plant, (Ricinus communist L.) is a member of the Euphorbiaceae, which contains a vast number of plants mostly native to the tropics (Akpan, et al. 2006 ). In Nigeria, castor is obtained in every part of the country. Its seed contains 40 to 60 % oil (Olaoye, 2000). The seed is referred to differently depending on the locality where it is found. The Yorubas call it ‘Lara’, the Hausas refer to it as ‘Zurma’, and the Kanuris call it ‘Kwolakwola’, while the Igbos refers to it as Ogilisi (Oluwole, 2010). The oil extracted from the seed is traditionally used as medicinal ointment, illuminant, and as raw material in the soap making industry. At present, the potential of castor oil is not fully explored in Nigeria. Figure 1 shows the pods of four common varieties of the crop that have been identified. These have been named as White Big Size (WBS), Black Big Size