Synthetic antioxidants and metallic elements as additives/contaminants in virgin palm oil
Oladunni Bola Olafisoye1, Oluwafemi Omoniyi Oguntibeju2*, Otolorin Adelaja Osibote3
1Faculty of Applied Sciences, Department of Chemistry, Cape Peninsula University of Technology, Cape Town, South Africa
2Faculty of Health and Wellness Sciences, Department of Biomedical Sciences, Phytomedicine & Phytochemistry Group, Cape Peninsula University of Technology, Bellville, South Africa
3Faculty of Applied Sciences, Department of Mathematics and Physics, Cape Peninsula University of Technology, Cape Town, South Africa
Abstract
This study evaluated the quantitation of synthetic phenolic antioxidants and trace elements in virgin palm oil. A Reverse Phase High Performance Liquid Chromatography coupled with Ultra Violet Visible detection spectrophotometry was employed for the analysis of synthetic antioxidants. The synthetic antioxidants studied were Butylatedhydroxyanisole (BHA), Butylatedhydroxytoluene (BHT), 2-ethylhexyl 4 methoxycinnamate (EEMC) and Propyl gallate (PG). A proposed ICP-OES using oil-water micro emulsion as sample preparation method was used for metallic element analysis because it is not only reproducible, accurate and reliable but also convenient because it provided a sample extraction capable of breaking down the complex matrix in virgin palm oil. The limits of detection for BHA, BHT, EEMC and PG were found to be 0.041, 0.057, 0.06 and 0.03 mg/L respectively while the limits of quantification values were 0.56, 0.49, 0.05 and 0.04 mg/L respectively. None of the synthetic antioxidants was detected in the samples studied. This was an indication that local farmers probably preserved the oil samples prior to storage by traditional methods. The elemental analysis of virgin palm oil is necessary to decide if the oil is suitable for food, fuel or raw materials for the chemical industry. The concentrations of metallic elements found in the oil samples analysed in this study ranged between 0.006 mg/kg in Ubiaja plantation and 161.576 mg/kg in Benin City plantation respectively. Tin recorded high concentration in Benin City plantation and Pb a low concentration in Ubiaja plantation. The concentrations of metallic elements were rather high in most samples hence the oil is best suitable for use as raw material for the chemical industry. It can therefore be concluded that the level of environmental pollution on the plantation be eradicated or reduced to the barest minimum to improve the quality of the virgin palm oil for human consumption.
