Chemical Compositions and Antioxidant Activitiesof Teas in Fujian

Chemical compositions and in vitro antioxidantactivities of major types of teas in Fujian were analyzed. Twenty-five samplesof 4 classifications of the green, white, Fujian oolong (southern and northern varieties),and black teas were collected and extracted with boiling water for the chemicaldetermination. The analytical results on the aqueous extracts showed significantdifferences on tea polyphenols, free amino acids,soluble sugar, DPPH free radical scavenging activity, and the ferric reducingantioxidant power (FRAP) among the 4 types of tea (P<0.05). The distribution patterns of EGCG, ECG, andtotal catechins were basically identical to that of polyphenols in the teas. The chemical compositionsand antioxidant activities were similar between the green and the white teas,so were between the southern and the northern Fujian oolong teas. The teas undergoneless fermentation in processing were generally higher on their antioxidantcapacity, of which, polyphenols were the major responsible compound.