Abstract: The glycerides compositions of pressed and extracted camellia oil were comparatively investigated by lipidomic ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry (UPLC-QTOF-MS). A total of 55 glycerides, including 43 triacylglycerols (TAGs) and 12 diacylglycerols, were detected utilizing information dependent acquisition (IDA). TAG 54:3 was the most predominant triacylglycerol found in both pressed and extracted camellia oil, accounting for more than 30% of the total triacylglycerols, and its content differed but not significantly between the oils (P > 0.05). Unsupervised principal component analysis (PCA) was performed with 55 glycerides as variable parameters. The two-dimensional PCA score plot showed clear separation between the oils. Furthermore, a predictive model was established using supervised orthogonal partial least squares discriminant analysis (OPLS-DA) for distinguishing the oils. The validation results showed that model could accurately distinguish the pressed oil from the extracted camellia oil with good recognition ability and prediction ability. This study provides a new research idea for identifying high-value edible oils produced by different processing methods.

Key words: ultra-high performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry; pressing; extraction; camellia oil; chemometrics