Volatiles, polysaccharides and total polyphenols in Chinese rose tea infusions and their antioxidant activities

Abstract

Rose tea is a kind of popular beverage in many Asian countries. In this study, the contents of volatiles, polysaccharides and total polyphenols in three species of Chinese rose tea infusions [Kuishui Rose (KSR), Pinying Rose (PYR) and Jinbian Rose (JBR)] were determined, respectively. Meantime, the volatiles from those three tea infusions were analyzed by GC-MS, and their antioxidant activities were tested by 1,1-diphenyl-2-picrylhydrazyl radical scavenging assay. As results, 17, 15, and 20 components were identified in their volatiles, respectively. The contents of volatiles, polysaccharides and total polyphenols, and the antioxidant activity of PYR tea infusion were higher than those of other two tea infusions. To elucidate the contributions of those main constituents in rose tea for its activity, correlation coefficients between them were analyzed, displaying that the polysaccharides and polyphenols are the main antioxidants in rose tea infusion, whose correlation coefficients were greater than 0.9. Practical applications As a kind of beverage with health care function, the activities and active ingredients of rose tea have mainly focused on polyphenols and their antioxidant so far. The current studies on the contents of volatiles, polysaccharides and total polyphenols and the antioxidant activities of rose tea infusions from three species in China could provide an useful comparison of the difference of antioxidant activities and constituents in those three rose teas and a basic data for quality control of rose tea.