Citrus Seeds as a Potential Source of Oil for Domestic, Industrial and Medicinal Purposes

Abstract

Citrus sinensis seeds have a lot of nutritional values as well as biological effective compounds responsible for the treatment of various diseases in the human body. However, greater percentage of the oranges gets rotten and this brings about reduction in the market value and an economic loss to the farmers who are into orange farming. The orange seeds are discarded as waste after the juice has been extracted. This has contributed greatly to environmental pollution. Also, there is an increase in demand of vegetable oils which has led to an increase in prices of vegetable oils. Seeds of sweet oranges (Citrus sinensis) were analyzed for oil and fatty acid composition. The crude oil was extracted by the use of soxhlet extraction. The results showed that oil content is as high as 71 %. The physico-chemical assessment gave the following results: refractive index (1.457), saponification value (165 mgKOH/g), peroxide value (4.12 meq/kg), iodine value (34.06 Wijs), moisture (5.803 ±0.1%) and ash (0.23 ± 0.15%). Crude fat (89.251 ± 0.2) with energy contents in the oil (803.261 Kcal/100g). The ATR-IR spectrum of oil showed prominent bands which was characteristics of unsaturated fatty acid. GC-FID analysis of fatty acid composition of Citrus sinensis seed oil indicated dominant fatty acids: Palmitoleic acid (C16:1), Linoleic acid and Palmitic acid (C16:0) with percentages 56.39%, 39.82% and 2.06% respectively. The fatty acid with the highest percentage composition (56.39%) is Palmitoleic acid (C16:1) a monounsaturated fatty acid. The Citrus sinensis seed oil showed greater degree of unsaturation forming 96.97% of the total fatty acids and 3.088% of saturated fatty acids. The oil was screened for antioxidant activities using 2, 2-diphenyl-1-picrylhydrazyl (DPPH), 2, 2’- azino-bis (3-ethylbenzthiazoline-6-sulfonic acid (ABTS) and phosphomolybdenum assays. These results indicated that the seed oil of sweet orange is possible suitable for both human consumption and industrial importances. © University of Cape Coast https://ir.ucc.edu.gh/xmlui