COMPARATIVE ANALYSIS OF THE CHEMICAL AND PHYSICAL PROPERTIES OF SEEDS AND OIL FROM TWO VARIANTS OF CASTOR PLANT (Ricinus communis L.)

Abstract

A need exists to bring to the attention of Nigerians some important plants whose seed and oil has been neglected. A typical example is the castor seed and oil and this could be achieved by generation and transmission of information. This study seeks to evaluate some chemical and physical properties of two variants of castor seed and oil that is the Black Big Size (BBS) and Grey Small Size (GSS). Using standard laboratory methods and conditions, the experiments were conducted and the results of the experiments showed that ‘BBS’ variety of castor seed has the following chemical properties: ash (3.43%), crude oil (46.58%), crude fiber (8.43%), crude protein (22.06%) and carbohydrate (9.43%) and physical properties: moisture content (8.0%), length  (l.57cm), width (1.18cm), thickness (0.71cm), weight (0.691g), slenderness ratio (1.331) sphericity (0.643cm³), and bulk density (0.4565g/cm³), while the oil has the following chemical properties : acid value (1.54mgKOH/g oil), iodine number (79.10), peroxide value (7.6meq/Kg oil), saponification value (172.51mgKOH/g oil), unsaponifiable matter (0.62) and physical properties: viscosity at 25^oC (7.8), specific gravity (0.9540) and refractive index (1.4790). The “GSS” variety of castor seed has the following chemical properties: ash (2.9%), crude oil   (33.2%), crude fiber (0.5%), crude protein (18.1%), carbohydrate (33.0%) and physical properties: moisture content (12.3%), length (1.32cm), width (0.82cm), thickness (0.56cm), slenderness ratio (1.605), bulk density (0.5433g/cm3), and sphericity (0.774 cm3). The oil has the following chemical properties: acid value (2.0mgKOH/g oil), iodine number (84.0), peroxide value (3.4meq/kg oil), saponification value (178.12mgKOH/g oil), unsaponifiable matter (0.6) and physical properties: viscosity at 25^oC (8.3), specific gravity (0.9651), refractive index (1.4761). From the results obtained from this study, which falls within the Codex standard for crude vegetable oil, Castor seed and oil plays a key role in both domestic and industrial applications especially the Black Big Size (BBS) and Grey Small Size (GSS) and this could be exploited by Nigerian Agriculturists.