Authentication ofCamellia oleiferaAbel Oil by Near Infrared Fourier Transform Raman Spectroscopy

Adulteration of Camellia oleifera Abel. oil with other cheaper oil has been a long-term problem in Taiwan because the price of Camellia oleifera Abel. oil is much higher than that of other edible oils due to its distinguished physiological properties. To develop an efficient method for determining the authenticity of Camellia oleifera Abel. oil is of great importance. In previous study (Appl. Spectrosc. 2003, 57, 413), we showed that the Raman intensity ratio of ν1656/ν1439 was capable of reflecting precisely the degree of unsaturation in edible oils. Accordingly, we further present this Raman method to determine the authenticity of Camellia oleifera Abel. oil. It showed that the intensity ratio (Iν1656/ν1439) changed concomitantly with the magnitude of double bonds in the binary mixtures of Camellia oleifera Abel. oil blended with other edible oil. A linear relationship with a high correlation coefficient (R2 = 0.9938) between the Raman intensity ratio of ν1656/ν1439 and the percentage of Camellia oleifera Abel. oil was obtained, which could be used to determine the authenticity of Camellia oleifera Abel. oils collected from various markets. It shows that FT-Raman spectroscopy provides a direct, simple, rapid, and non-invasive method to probe the authenticity of Camellia oleifera Abel. oil.