Extraction and Comparative Characterization of Oils from Edible Seeds of Glycine max and Sesamum indicum

Abstract

Aim: The incidence of heart-related disease conditions due to consumption of cholesterol containing oils and the increasing global demand for oil for domestic and industrial purposes have necessitated the need for scientific evaluation of other neglected indigenous plants for potential quality oil yield. This study thus aimed at extracting and comparing physicochemical and nutritional properties of seed oils from Glycine max and Sesamum indicum with a view to diversifying alternative sources of oil to meet teeming industrial and health needs and for food security.
 Methodology: Solvent extraction method was employed to extract oil from seed samples which were further subjected to estimation of physicochemical indices such as free fatty acid, saponification value, iodine value, peroxide value, specific gravity, refractive index, density, pH, melting temperature and viscosity according to methods described by using titration method.
 Results: Findings indicated higher saponification (412.33 mgKOH/mg), acid (2.99 mgKOH/g), free fatty acid (1.49 mgKOH/g), viscosity (0.13 Pas) and melting point (5.66 oC) values for sesame seed oil than for soybean seed oil. However, soybean seed oil showed higher density (0.837 g/ml), specific gravity (0.842 Kg/m3), pH (6.21), iodine (47.25 wij’s or g/iodine/g) and peroxide (40.80 mEq/Kg) indices than that obtained for sesame seed oil though mean values were not significantly different.
 Conclusion: From observed measured parameters, sesame seed may be suitable for industrial purposes such as the production of soap and paint owing to its high saponification, free fatty acid, viscosity and melting point values while soybean seed oil may be excellent source for domestic and nutritional consumption in addition to industrial use.

Chemical Composition, Quality Indices and Viscosity of Edible Oils from Blends of African Oil Bean Seed Oil and Sesame Seed Oil

“…The acid value obtained in this study was lower than 19.21 mg KOH/100 g reported for soybean oil but higher than the value (4.63 mg KOH/100g) reported for groundnut oil (Amos-Tautua et al, 2013). More so, the acid value of sesame seed oil (SS100) of the present study is 5.76 mg KOH/100 g which is higher than 2.99 mg KOH/g and 4.44 mg KOH/g reported by Enemor et al (2021) and Benítez-Benítez et al (2016) respectively, while the acid value of African oil bean seed oil (AB100) of the present study is 8.08 mg KOH/g which is higher than 1.40 mg KOH/1g, 5.84 mg KOH/g and 1.23 mg/KOH/g reported by Enemor et al (2021), Benítez-Benítez et al (2016 and Okoye (2016) respectively but lower than 8.18 mg KOH/g reported by Akinlabu et al (2019). Furthermore, the acid values of the oils except control exceeded the CODEX standard for acid value of edible oil (<1.0 mg KOH/100 g) (Codex, 2011), thus, inferring high amount of FFA and recommendation for refining process.…”

“…Higher saponification value of oil blends is an indication that the oil blends may contain higher concentration of short chain fatty acids that favours stability as well as low level of impurities and adulteration and could be useful for industrial applications such as soap making. Findings from this study for sesame seed oil (SS100) corresponds with 189.80 mg/100 g -195.3 mg/100 g reported by El-Beltagi et al (2022), 193.01 mg KOH/g reported by Benítez-Benítez et al (2016), 190.00 mg KOH/g reported by Chakraborty et al (2017), 190.74 mg KOH/g reported by Dim et al (2012) and 190.80 mg/100 g -201.3 mg/100 g reported by Rizki et al (2014) for sesame seed oils but lower than 412.33 mg KOH/g reported by Enemor et al (2021). More so, the SV of African oil bean seed oil (AB100) (208.67 mg KOH/g) was higher than 193.120 mg KOH/g reported by Ordu & Yingobo (2021), 152.72 mg KOH/g reported by Okpo & Evbuomwan (2014) but corresponds with 207.54 mg KOH/g reported by Okoye (2016).…”