Evaluations of Seed Oil from Nigerian grown Sweet Orange for its Nutritional quality and Industrial Applications

Abstract

Oil was extracted from the dried, powdered seeds of orange (citrus sinensis) by cold extraction in n-hexane. 5 g of ground seed sample was used to determine the Oil content using Soxhlet extractor at 60 ^oC. The seed yielded 35.00 ± 0.54 % of the oil. The physicochemical properties of oil, such as specific gravity (0.8695 @ ^oC), viscosity (1.3008 ± 0.006 @ 26 ^oC), refractive index (1.453 @ 25 ^oC), free fatty acid (2.31  ± 0.01 %), acid value (3.14  ± 0.05 mgKOH/g), saponification value (192.56  ± 0.39 mgKOH/g), iodine value (108.03 ± 0.16 g/100g), and peroxide value (9.38 ± 0.07 meq/kg) were determined. The oil was also subjected to gas chromatography – mass spectrophotometric (GC-MS) analysis which revealed that the oil was rich in Linoleic acid (C18: 2) 89.25 % and contain other fatty acids at different percentages as follows:  Palmitic acid (C16:0) 1.57 %; Oleic acid (C18:1) 7.96 %; Linolenic acid (C18: 3) 1.21 %. There was a strong correlation between the parameters examined which was statistically significant at the 0.01 level (2-tailed) (r = 0.994, N = 3). This shows the physicochemical parameters examined are interdependent. The results obtained from the physicochemical characterization of the oils also show that the property of  orange seed oil compares with the other seed oils and has high potentials for use both as domestic (edible as nutritional source) and industrial oil (Cosmetics production, pharmaceutical use as Omega 3 precursor).