Oil produced from Ghana cocoa bean for potential industrial applications

Abstract

Cocoa bean (Theobroma cacao) oil is a promising intermediate cocoa product with few research demonstrating its potential for the direct production of industrial cocoa products. The liquefied form could be utilised as an intermediate cocoa bean product to manufacture industrial cocoa products with a controllable yield and low cost. This study highlights the extraction and characterisations of oil obtained from the Ghana cocoa bean crop to evaluate its suitability for industrial applications. A solvent extraction method was employed to extract the oil at variable extraction temperatures and times. Kinetic and thermodynamic models were adopted to study the oil's extraction at varying temperatures and times. The maximum yield of the oil (21.62%) was reached at the highest temperature and time at 333 K and 130 min, respectively, following first-order kinetics. The thermodynamic studies indicated that the extraction process is a forward, irreversible, endothermic, and spontaneously favourable process with activation energy 15.57 kJ mol-1. Next, the physicochemical properties were below the recommended values and acceptable for industrial and commercial applications. For instance, the oil's iodine, peroxide, saponification, unsaponification, and free fatty acids were below the recommended standards acceptable for industrial applications. The gas chromatography identified stearic acid (37%), oleic acid (34%), and palmitic acid (26%) as the major fatty acids in the oil. Differential scanning calorimetry “thermal gravimetric studies showed that the oil was thermally stable at high temperatures until thermal decomposition occurred around 260°C. Likewise, computational modelling and Fourier infrared red spectroscopy analysis revealed that the oil was highly stable to thermal oxidation despite the high temperatures employed for the extraction process. All in all, the results indicate that the extraction process can be optimised to maximise the oil's yield and reduce production costs. The oil's chemical and physical properties make it a suitable intermediate cocoa product for industrial applications.