Physicochemical Characterisation and Potential Uses of Oils From the Entrails of Nile Tilapia From Different Farming Sites in Ghana

Abstract

The Nile tilapia, a fish of the Teleost group, is economically valuable due to its ease of cultivation, high growth rates and resistance to environmental conditions and is increasingly used for waste conversion. The aim of this study was to evaluate the physiochemical properties and potential applications of oils derived from the entrails of Nile tilapia obtained from four different farming sites in Ghana. The tilapia fish oil (TFO) was extracted by the wet rendering method. The refractive index, fatty acid profile, colour and cholesterol content of the TFO samples (TFS1, TFS2, TFS3 and TFS4) were determined using a refractometer, GC–MS, chromameter and UV spectrophotometer, respectively. More than 65% of fatty acids present in TFS1 to TFS4 were unsaturated fatty acids (UFAs). Oleic acid and its isomer were present in the oils as follows: TFS2 (58.37%), TFS3 (57.28%), TFS1 (43.89%) and TFS4 (41.71%). The following physicochemical properties of TFS1 to TFS4 were determined: vitamin A (0.70–2.15 mg/100 g), vitamin E (0.03–0.009 mg/100 g), acid value (0.27–0.66 mg KOH/g), peroxide value (0.009–4.488 meq/kg), iodine value (77.87–74.62 mg/g), saponification value (247.93–592.27 mg KOH/g), cholesterol content (162.33–438.33 mg/100 mL) and moisture content (1.08%–3.25%). These findings indicate that TFOs have potential applications in the food and pharmaceutical industries. However, the differences in physicochemical properties must be considered during product development to ensure optimal quality and marketability of the final product.