title: Influence of different fermentation raw materials on pyrolyzates of Pu-erh tea theabrownin by Curie-point pyrolysis-gas chromatography-mass spectroscopy.
abstract: METHODS
  In this study, Pu-erh tea was prepared by solid-state fermentation of the sun-dried green tea, short-fermentation black tea, and black tea. Ultraviolet-visible spectroscopy, infrared spectroscopy and Curie-point pyrolysis-gas chromatography-mass spectroscopy (CP-Py-GC/MS) were used to study the characteristics and chemical compositions of the TB formed in these Pu-erh teas.
  
  
  RESULTS
  The pyrolysates of the Pu-erh teas' theabrownin (TB1, TB2, TB3) were analyzed at 386°C using a Curie point pyrolysis instrument. TB1, TB2, and TB3 produced 158, 135 and 148 pyrolysis products, respectively. These compounds could be grouped as follows: alkaloids, 25.23% (TB1), 25.67% (TB2), and 21.91% (TB3); phenols, 24.19% (TB1), 23.08% (TB2), and 29.91% (TB3); nitrogen-compounds, 11.79% (TB1), 11.25% (TB2), and 13.39% (TB3); hydrocarbons, 10.96% (TB1), 10.37% (TB2), and 11.37% (TB3); ketones, 10.34% (TB1), 6.58% (TB2), and 8.22% (TB3); furan, 5.40% (TB1), 4.06% (TB2), and 2.33% (TB3); alcohol, 3.30% (TB1), 4.16% (TB2), and 3.34% (TB3); fatty acids, 2.80% (TB1), 4.03% (TB2), and 1.42% (TB3); esters 2.17% (TB1), 0.99% (TB2) and 2.35% (TB3); and amines 1.61% (TB1), 2.81% (TB2), and 0.86% (TB3).
  
  
  CONCLUSIONS
  Theabrownin mainly contains alkaloids (caffeine), tea pigments, polysaccharides, proteins and lipids. Its precursors include various polyphenols, tea pigments, alkaloids, polysaccharides, proteins and lipids. These compounds in the raw materials impact the chemical composition of theabrownin, and black tea is not a suitable raw fermentation material for Pu-erh tea.
authors.affiliation: Horticultural Department, Yunnan Agricultural University, Kunming, Yunnan 650201, China.
authors.forename: Chun-xiu
authors.initials: CX
authors.lastname: Peng
authors.forename: Jian
authors.initials: J
authors.lastname: Liu
authors.forename: Hua-rong
authors.initials: HR
authors.lastname: Liu
authors.forename: Hong-jie
authors.initials: HJ
authors.lastname: Zhou
authors.forename: Jia-shun
authors.initials: JS
authors.lastname: Gong
mesh_terms: D002392:Catechin / Q000031:analogs & derivatives* / Q000737:chemistry; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D010636:Phenols / Q000032:analysis; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D013662:Tea / Q000737:chemistry*; D013696:Temperature
chemical_list: D010636:Phenols; D013662:Tea; C569455:theabrownin; D002392:Catechin