Investigation on the Changes in Non-volatile Metabolites of Raw Pu-erh Tea during Manufacturing
Ultra-high performance liquid chromatography-high resolution mass spectrometry(UPLC-HRMS)was employed to comprehensively analyze the non-volatile compounds of raw Pu-erh tea(RPT)and their changes during the manufac-turing process.The results showed that a total of 141 compounds were identified or annotated in RPT samples.The con-tents of 25 compounds changed significantly and were screened as differential compounds(VIP>1,P<0.05).Among the four major processing stages,de-enzyming and autoclaving-compressing treatments were the key processes that caused the changes of these compounds.De-enzyming remarkably reduced the contents of most monomeric catechins and amino acid,while autoclaving-compressing dramatically increased the contents of monomeric catechins but significantly reduced the contents of alkaloids and amino acids.It is beneficial to explore the quality formation during the production of RPT through comprehensive analysis of the changes in non-volatiles.
raw Pu-erh teamanufacturing processnon-volatilesUPLC-HRMS