Extraction, Physicochemical and Phytochemical Characterization of Oil from Sesame Seed

Abstract

The objective of this research was to extract (using cold press and soxhlex extraction method), determine the physicochemical characteristics and characterization of the oil from Sesame indicum seed by GC-MS analysis. Output yield gave an average of 28.23 and 46.60 % oil yield for cold and hexane solvent extraction method respectively. The extracted oil had a pH value of 5.34 and 5.87; viscosity of 32.45 and 29.50 mpa.s; refractive index of 1.4689 and 1.4684 and specific gravity of 0.9183 and 0.9182 for cold press and hexane solvent extracted oil respectively. The data indicated that there was a marked variation in iodine value, saponification value, free fatty acids, and peroxide value between the sesame oil from cold press and hexane solvent extraction method. There values were:  Peroxide value which is an indication of the ability of oil to get rancid was 5.84 and 5.61 meqO2/kg oil; Iodine value was 83.73 and 92.38 I2g/100goil; acid value was 6.09 and 5.87 mgKOH/goil, while the free fatty acid value was 3.04 and 2.92% respectively. Saponification values obtained were 212.45 and 214.53 mgKOH/goil respectively. The data revealed that cold press oil recorded higher L, a and b values than that of hexane solvent extracted oil. According to the Gas chromatography-Mass spectrometry (GC-MS) results of the phytochemical analysis cold press sesame seed oil extract contains six (6) bioactive compounds namely; 9-Methyl-Z,Z-10,12-hexadecadien-1-ol acetate (1.00%), 6-Methyltetrahydro-1,3-oxazine-2-hione Z,Z- (0.57%), Z,Z-4,16-Octadecadien-1-ol acetate (0.36%), 9,12-Octadecadienoic acid (Z,Z) (97.83%), 2-Pentadecanol (0.10%) and 2-Pentadecanol (0.13%) and hexane solvent extracted sesame seed oil also contain six (6) bioactive compounds from which includes limonene (0.93%) Carbonic acid, prop-1-en-2yltridecyl ester (0.14%), 9, 12-Octadecadienoyl chloride (Z: Z) (Linoleoyl chloride) (0.39%), 2-piperidinone, N-(4-bromo-n-butyl) - (0.20%) 17-pentatriacontene (1.12%) and Hexadecanoic acid (palmitic acid) (97.21%); of which 9,12-Octadecadienoic acid (Z,Z) (97.83%), and Hexadecanoic acid (palmitic acid) (97.21%) were the major constituent with the biological activities like antimicrobial, antifungal and antioxidant activity present in the oils.