Physico-Chemical Properties, Chemical Composition, Biodiesel Production and Antibacterial Potential of <i>Terminalia catapa</i>Seed Oil

Abstract

Terminalia catapa (Almonds) are highly nutritional powerhouses full of healthy fats, fibres, phytochemicals, vitamins and minerals. Its usefulness includes food and for the production of some other desirable necessities to man. The aim of this study was to extract, characterize, determine the chemical constituents and investigate the antimicrobial potential of oil from almond seed, as well as biodiesel production. All analyses were done using established methods. The result obtained showed the proximate composition with moisture content (20.00%), crude fat (20.60%,) protein (25.60%,),carbohydrate (25.60%,), ash (4.80%) and crude fibre (3.40%). The physicochemical properties of the T. catapppa seed oil were moisture (0.20%), specific gravity (0.90g/cm³), viscosity at 40^oC (27.50 mPa.s), cloud point (15.00oC), pour point (11.00^oC), smoke point (170.00^oC), flash point (203.00^oC), fire point (265.00^oC), acid value (2.94 mgKOH/g), free fatty acid (FFA) (1.74 mgKOH/g), saponification value (326.08 mgKOH/g), Iodine value (131.37 gI2/100g) and Peroxide value (3.81meq/kg). The biodiesel produced had a percentage yield of 36.9% with the physicochemical properties including specific gravity (0.89g/cm³), viscosity at 40^oC (5.8 mPa.s), cloud point (7.0^oC), pour point (6.0^oC), smoke point (161.0^oC), flash point (215.0^oC), fire point (186.0^oC), acid value (0.76 mgKOH/g), FFA (0.38 mgKOH/g), saponification value (313.45 mgKOH/g), Iodine value (54.56 gI2/100g) and Peroxide value (4meq/kg). A total of 21 compounds were identified from the T. catapa seed oil by the GC-MS, with the major constituents being fatty acids; n-Hexadecanoic acid (17.96%), Oleic acid (22.42%) and 2,9-octadecadienoic acid (22.82%)by composition. The oil also demonstrated a good antibacterial potential at all concentrations (50, 75, 100 and 125 mg/mL) against all tested isolates (Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Bacillus sp). The results obtained revealed that the oil from almond seed may possibly find its useful application in the cosmetic industry, and could also be a promising source of renewable energy.