Multi-marker UPLC-MS/MS detection of sesame, soybean, and peanut oil adulteration in camellia and olive oils: a high-sensitivity approach for food authenticity

This study developed a rapid and sensitive ultra-performance liquid chromatography-tandem triple quadrupole mass spectrometry (UPLC-MS/MS) method to detect adulteration of high-value camellia oil and olive oil with lower-cost sesame, soybean, and peanut oils. Four characteristic markers-sesamin and sesamolin (sesame oil), 4′,7-dimethoxyisoflavone (soybean oil), and sativanone (peanut oil) were identified and quantified with high specificity. Method validation demonstrated excellent linearity ( r  > 0.997), recoveries (70%–110%), and precision (RSD < 6.1%). The limits of detection were 0.025%–0.10% for sesame oil, 1.0%–5.0% for soybean oil and peanut oil. Adulteration model experiments and method comparison analysis confirmed reliable multi-component adulteration detection in complex matrices. Analysis of 106 commercial samples revealed adulteration rates of 16.0%(camellia oil) and 25.0%(olive oil), primarily with soybean oil. Notably, the analysis of two law enforcement samples confirmed adulteration with soybean oil, consistent with the official regulatory findings. This approach overcomes limitations of traditional methods, offering a robust tool for safeguarding oil authenticity and consumers' rights.