Abstract

Carica papaya is a fruit known for its great economic values in tropical Africa due to its diverse industrial, medicinal and nutritional benefits. In this study, oil was extracted from dried powdered C. papaya seeds using n-hexane as extraction solvent. The physiochemical characterization of C. papaya seed oil extract was investigated using AOAC standard procedures. Acute toxicity test was carried out to determine the toxicity of the oil. Rats were randomly divided into four groups with five rats per group. Groups B, C and D were given 200, 400 and 800 mg/kg body weight of the seed oil thrice in a week for 28 days while group A rats were not administered with the oil. The results obtained from the physical properties of the Carica papaya seed oil include: oil yield (30.31±2.38%), colour (golden yellow), specific gravity (0.9162±0.012), refractive index (1.468±0.22), viscosity (22.45±2.00 mms-1), melting point (42.30±3.0°C), smoke point (212.13±9.0°C) and flash point (274.74±12°C). The chemical properties indicate the presence of acid value (2.848±0.28%), free fatty acids (1.29±0.16%), saponification value (mg KOH/g) (192.06±1.62), iodine value (70.78±1.69 gI2/100 g) and peroxide value (5.079±0.079 meq/kg). The fatty acid profile of the seed oil shows that it contains: oleic acid (73.36±1.07%), palmitic acid (14.36±0.96%), stearic acid (5.09±0.5%) and linoleic acid (4.56±0.20%). The total composition of unsaturated and saturated fatty acids in the seed oil was 79.52 and 20.48%, respectively. The oil exhibited viable potentials for biodiesel feedstock based on the results of the physicochemical parameters. The biochemical parameters show that the oil is hematotoxic and it causes significant (P<0.05) increase in total cholesterol, triglyceride and low density lipoprotein-cholesterol values. The high density lipoprotein-cholesterol and catalase did not show any significant (P>0.05) difference among all groups. The oil has slight effect on the kidney and the heart architecture.

Key words: Biodiesel, biochemical parameters, Carica papaya seed oil, histopathology.