Altitude and regional differentiation of dark tea using non-targeted metabolomics based on UHPLC-Q-Exactive Orbitrap MS

Dark tea, being a fermented variety, is intrinsically linked to its regional provenance in terms of its quality and market value. Therefore, precisely verifying the geographical origin of dark tea is essential for guaranteeing its quality and establishing its market value. The study used a method called non-targeted metabolomics and ultra-high-performance liquid chromatography-quadrupole-electrostatic field Orbitrap mass spectrometry (UHPLC-Q-Exactive Orbitrap MS) to find out what chemicals are in dark tea from different parts of the world. Chemometric modeling was utilized to ascertain the origin of the tea. Through non-targeted metabolomics analysis of 47 dark tea samples, 12 principal metabolites were identified, predominantly determined by altitude. An orthogonal partial least squares-discriminant analysis (OPLS-DA) validation model was built utilizing these differential metabolites. Additionally, this study developed a method that integrates geographical characteristics, including altitude, and created OPLS-DA validation models for each region. Following model fitting, validation, and discrimination training, the findings indicated no overfitting, with accuracy rates for both the training and validation sets achieving 100%. This study’s method demonstrates considerable promise for identifying the geographical origin of dark tea and establishes a robust basis for origin identification in fermented foods.