Differential Scanning Calorimetric Analysis of Virgin Coconut Oil, Palm Olein, and their Adulterated Blends
Abstract
Virgin coconut oil (VCO) is a premium product with a high market value. Its authenticity and quality assurance are important to safeguard consumers from fraudulent practices. The aim of this study was to investigate the effect of adulteration by palm olein (PO) on differential scanning calorimetric (DSC) heating and cooling profiles of VCO. Pure samples of VCO, PO and their adulterated blends (5 to 30%, w/w) were subjected to thermal analysis by DSC according to a specified temperature program. DSC thermal analysis system software and SAS statistical system were used subsequently to analyze thermal data. Both cooling and heating curves of VCO were found to be vivid for fingerprint comparison of qualitative identification at 5% level of adulteration.
References
Dyszel, S. M., and Baish, S. K. 1992. Characterization of tropical oils by DSC. Thermochim. Acta 212: 41–49
Jayasundera, M., Yalegama, C., Dharmasena, A. and Jayathilake, S. 2003. Dry processing of virgin coconut oil. In: Report of the Coconut Research Institute of Sri Lanka for 2003, Jayasekera, C. and Jayamanne, J.M.T.D. (Eds.) pp. 168–169, Lunuwila.
Marina, A. M. Che Man, Y. B. Nazimah, S. A. H., and Amin, I. 2009. Monitoring the adulteration of virgin coconut oil by selected vegetable oils using differential scanning calorimetry. Journal of Food Lipids 16: 50–61.
Manaf, M. A., Che Man, Y. B., Hamid, N. S. A., Ismail, A. and Abidin, S. Z. 2007. Analysis of adulteration of virgin coconut oil by palm kernel olein using Fourier transform infrared spectroscopy. Journal of Food Lipids 14: 111–121.
Marikkar, J.M.N. 2015. DSC as a valuable tool for the evaluation of oils and fats adulterations. In: Differential Scanning Calorimetry: Applications in Fat and Oil Technology, Emma Chiavaro (Editor). CRC Press, Taylor & Francis Group, Florida, USA. pp. 159–178. ISBN: 9781466591523
Marikkar, J. M. N., Saraf, D. and Dzulkifly, M. H. 2013. Effect of fractional crystallization on composition and thermal behavior of coconut oil. International Journal of Food Properties 16: 1284–1292.
Nevin, K.G. and Rajamohan, T. 2004. Beneficial effects of virgin coconut oil on lipid parameters and in vitro LDL oxidation. Clin. Biochem. 37, 830– 835.
Nagao, K. and Yanagita, T. (2010). Medium-chain fatty acids: Functional lipids for the prevention and treatment of the metabolic syndrome. Pharmacological Research. 61 (3): 208–212.
SAS Statistical Analysis System User’s Guide: Basic Statistics 1998. SAS Institute Inc. Cary, NC.
Xu, B., Li, P., Ma, F., Wang, X., Matthäus, B., Chen, R. and Zhang, Q. 2015. Detection of virgin coconut oil adulteration with animal fats using quantitative cholesterol by GC× GC–TOF/MS analysis. Food Chemistry 178:128–35.