Differentiation of vegetable oils and determination of sunflower oil oxidation using a surface acoustic wave sensing device

Abstract

A small portable electronic sensing device, utilizing the principle of surface acoustic wave (SAW), was used to differentiate between olive and sunflower oils of various brands. The oils were oxidized to determine if the sensing device could distinguish between fresh and oxidized oils. Good results were obtained, when adjusted total peak signal magnitude and sensor frequencies were plotted against oxidation time. The R 2 value of the sunflower oils was better than that of the olive oils. Hence, they were considered for analysis by headspace solid phase microextraction-gas chromatography/mass spectrometry (SPME-GC/MS) for comparison of results between the two methods (SAW sensing device (SSD) and SPME-GC/MS). SPME-GC/MS showed the presence of a number of compounds in the oils. However, acetic acid showed a consistent increase in terms of area count as compared to other compounds of the oils. Hence it was considered for a plot of response versus time. Pearson’s correlation was calculated using MINITAB statistical software. A high correlation was observed when responses from both methods were calculated. This led us to conclude that SSD could prove to be a valuable tool in quality control measurements in food industry.