Quality Parameters of Palm Olein, Palm Kernel Oil and its Blends Subjected to Thermal Stress using Photometric Technology

Abstract

There is no much information regarding the partial replacement of palm olein with palm kernel oil. Palm olein mixed with palm kernel oil is commonly sold in Nigeria market today without proper blending and without determination of their suitability to consumer also ignorant of what ratio to be blended. Therefore, blends of palm olein (POL) and palm kernel oil (PKO) were formulated to assess their stability under elevated temperature using a fast, simple and reliable CDR palm oil tester photometric technology. The results were then compared with those obtained in POL. The blends studied were to investigate the effects of palm kernel oil partial replacement on the chemical stability of palm olein. the blends as partial replacement were missed in the ratio of PKO:POL(100:0), PKO:POL(80:20), PKO:POL(60:40) and POL:PKO(100:0), POL:PKO(80:20), POL:PKO(60:40). The POL, PKO and its blends were heated at 100, 150 and 200ᵒC. The time of heating were 20, 40 and 60mins respectively, making a total of 1 hour for heating without any frying operations. The physicochemical properties of the oil samples were fatty acid composition, free fatty acid, peroxide value, iodine value, anisidine value, cloud point, colour, melting point, viscosity and totox value were evaluated over heating time. Blending palm olein (POL) unsaturated oils with saturated (PKO) generally improved the parameters comparable to those demonstrated in palm olein (POL) and palm kernel oil alone. The result showed that as PKO was increased the concentration of saturated fatty acid also increased while unsaturated fatty acid decreased. Saturated oils were generally more stable to oxidation and less sensitive to thermal stress. Increase in the amount of PKO lead to reduction in FFA.