The researchers from the Department of Analytical Chemistry at the University of Granada say the method could be used by both governments and industry, responding to a growing consumer demand for proof of palm oil origin.
“Palm oil is cheap, easy to obtain and has low production costs so the number of industrial palm plantations has recently been increasing. This increase in the number of plantations, however, has brought with it the destruction of the rainforest, the expulsion of the indigenous population and serious environmental problems such as deforestation and air pollution,” the write, and while certified sustainable palm oil is one solution, it can fall foul to fraud.
“The term 'sustainable palm oil' has sometimes been used to make an illicit profit. The labels of some products state that they contain 'certified sustainable palm oil' when in fact the oil used comes from unknown forest plantations. Consequently, customers are increasingly demanding some sort of proof of the geographical origin of products.”
According to this novel method they first analysed palm oil samples by liquid chromatography and then applied chemometric and data fusion strategies.
By combining these methods - the first time this has been carried out, they claim - they were able to extract the information required to determine the geographical origin of the sample with a low margin of error of around 5%.
Fusing the data "optimises the information obtained and exploits the synergies of information provided by different techniques", they write, and is also quicker and more accurate than current methods.
However, using more than one measuring technique can be more expensive, they add.
The scientists gathered 100 crude oil samples, supplied by Wageningen University’s Institute of Food Safety from the main palm-oil producing countries, with 56 samples from South-East Asia (Malaysia, Indonesia, Papua New Guinea and the Salomon Islands), 30 samples from West Africa (Ghana, Guinea, Ivory Coast, Nigeria and Cameroon) and 16 samples from Brazil in South America.
“This study shows the advantages of applying data fusion strategies that provide complementary information. All three data-fusion methodologies were better at authenticating the geographical origin of palm oil than the individual models (HPLC-UV and HPLC-CAD), which shows that the information obtained from both chromatograms (HPLC technique coupled to two different detectors) has a synergistic effect.”
“HPLC-UV and HPLC-CAD chromatographic data fusion for the authentication of the geographical origin of palm oil”
Published online ahead of print, DOI: https://doi.org/10.1016/j.talanta.2017.04.035
Authors: K.A. Obisesan, A.M. Jiménez-Carvelo, L. Cuadros-Rodríguez, I. Ruisánchez and M.P. Callao