Comprehensive investigation on non-volatile and volatile flavor compounds in different varieties of rose tea by UPLC-Q-TOF-MS/MS-based metabolomics and GC-IMS, GC-MS

Abstract

This study aimed to analyze the quality differences of different varieties of rose tea. Ultra-high-performance liquid chromatography-quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF-MS/MS) was used to detect the metabolites in different varieties of rose to find out the differential metabolites.Forty-four phenylpropionic acid and polyketone compounds were found to the main differential metabolites in 6 different varieties of roses. Gas chromatography ion mobility spectrometry (GC-IMS) results revealed the presence of 15 potential differential compounds among different varieties of roses, with 1-penten-3-one (monomer) and ethyl propionate being the two most significantly different substances among the six different varieties of roses. GC-MS analysis of volatile flavor compounds in different varieties of rose tea showed that the concentrations of aldehydes, alcohols, alkanes, and phenols in XS rose tea were the highest, being 4.133 µg/g, 14.873 µg/g, 3.039 µg/g, and 2.399 µg/g, respectively. The concentrations of ketones, heterocyclic compounds, and ethers in KS rose tea are the highest, being 4.344 µg/g, 0.752 µg/g, and 0.234 µg/g, respectively. Phenyl-ethanol, citronellol, octanoic acid ethyl ester, and decanoic acid ethyl ester are considered to be the main factors in the formation of characteristic aromas in different varieties of rose tea.