Qualitative and Quantitative Analysis of Β-Sitosterol Marker in Virgin Camellia Oil and Virgin Olive Oil

Camellia oil and olive oil with superior economic value are easily adulterated with other, cheaper oils. It is difficult to identify both oils by traditional methods because of their similar fatty acid profiles. In the present study, a novel method for qualitative and quantitative analysis of ss-sitosterol using GC/MS and GC/FID was developed to identify camellia oil and olive oil. The method validation of ss-sitosterol analysis showed good linearity and satisfactory values for recovery, accuracy, precision, and repeatability. The linear regression coefficient (R2) of the calibration curve was 0.9985. An acceptable limit of detection (0.36 mg/100 g) and limit of quantification (1.20 mg/100 g) were achieved. The spiked recoveries were 95.0% to 100.3%. The relative standard deviation (RSD) of within-day precision was less than 3.26%, and the RSD of retention times and peak areas for repeatability were within 0.03% and 1.08%, respectively. The contents of ss-sitosterol in virgin camellia oil and virgin olive oil were in the range of 14.1-30.2 mg/100 g and 94.3-173.2 mg/100 g, respectively, indicating that the ss-sitosterol content in the former is seven times that in the latter, and ss-sitosterol could be a potential marker for the authentication and adulteration detection of both oils.