EVALUATION OF PHYSICOCHEMICAL CHARACTERISTICS, ANTIMICROBIAL PROPERTIES, FATTY ACIDS AND ALPHA-TOCOPHEROL CONTENT OF MORINGA OLEIFERA SEED OIL [MOSO] GROWN IN SOUTHWEST NIGERIA.

Abstract

The present investigation evaluated the physicochemical, alpha tocopherol content, fatty acid composition, and antimicrobial properties of Moringa oleifera seed oil [MOSO] extracted from M. oleifera seed indigenous to South-Western Nigeria. The oil yield obtained after Soxhlet [n-hexane] extraction of M. oleifera seeds was 37.35 ± 1.13%. The saponification value [mg of KOH g−1 of oil] of the extracted MOSO was 252.90 ± 2.78 while the acid value [mg KOH g−1 of oil] was 2.34 ± 0.23. The peroxide value [mequiv O2 kg−1] and iodine value [g of I2 100 g−1 of oil] were 4.89 ±0.42 and 67.68 ± 1.34 respectively. The specific gravity [@ 25 °C], refractive index [@ 40 °C], and viscosity [mpa.s @40 °C] were 0.90 ± 0.01, 1.464 ± 0.01, and 58.90 ± 3.52 respectively. Alpha-tocopherol [mg 100 g−1 of oil] content of the n-hexane extracted MOSO was 1.44 ± 0.01, and its corresponding mg/serving and percentage daily value [%] were 0.202 and 1.35 respectively. Chemical compounds identified by GC-MS analysis include Ethanol, 2-butoxy [7.56 %], Benzene-1-ethyl-4-methyl-[6.34 %], Benzene-1,2,3-trimethyl-[7.65 %], Benzene-1,2,4-trimethyl- [17.39 %] Isophorone [10.71 %], n-hexadecanoic acid [Palmitic Acid] [12.17 %], Oleic Acid [35.97 %], and Butyl- 9-octadecenoate [2.21 %]. The observed antimicrobial activity was concentration dependent. At 50 and 100 mg/ml, MOSO demonstrated intermediate antimicrobial activity against Escherichia coli, Candida albicans, Aspergillus niger, and Penicillum notatum while no activity was observed below 50 mg/ml. The examined MOSO exhibited good quality characteristics and could be utilized as alternative vegetable oil for food, industrial and pharmaceutical applications.