Chemical compositions of theabrownin extract from Pu-erh tea during fermentation by different microorganisms.

The variation of contents of theabrownin(TB),protein,polysaccharide,theaflavins(TF) and thearubigin(TR) in TB extracts from different piled-up samples of Pu-erh tea during fermentation by different microorganisms were studied.The contents of TB,polysaccharide and protein from extracts were increased during fermentation.Comparied with increasing of the content of TB,the content of TF and TR were reduced during fermentation.Moreover,the reduced values of TF and TR are less than the increased value of TB.In the last piled-up samples fermented with Trichoderma reesei,Aspergillus niger,yeast,Aspergillus oryzae and Rhizopus,the mass fractions of TB in different TB extracts were 35.30%,43.50%,39.21%,44.83% and 39.56%,respectively;the contents of theaflavin were 0.85%,0.77%,0.75%,0.77% and 0.89%,respectively;the contents of thearubigin were 0.53%,3.49%,0.26%,4.00% and 3.30% respectively;while the contents of polysaccharide were 27.81%,23.35%,33.09%,21.11% and 27.14%,respectively,and the contents of protein were 28.57%,26.96%,26.44%,26.00% and 26.61%,respectively,suggesting that chemical compositions among TB extracts from tea samples fermented by different microorganisms had significant difference.