不同焙火程度对武夷岩茶品质和抗氧化活性的影响

Effect of Different Baking Degree on Antioxidant Activity and Quality of Wuyi Rock Tea

试验分析了在不同焙火程度下武夷岩茶(金观音、丹桂、梅占、雀舌、奇丹)主要生化成分、感官审评及抗氧化活性的变化情况。结果表明,随着焙火程度的升高,水浸出物、氨基酸、茶多酚、咖啡碱和黄酮含量相比毛茶样都有所减少,以金观音水浸出物(11.32%)、丹桂茶多酚(16.86%)、奇丹氨基酸(40.95%)、梅占黄酮(13.57%)和奇丹咖啡碱(22.31%)减幅最大。通过感官审评发现,随着焙火程度增加,5个品种武夷岩茶品质都有所提升,以中焙火武夷岩茶综合得分最高。不同焙火程度的武夷岩茶清除有机自由基(DPPH·)的能力随焙火程度升高而减弱,其清除能力依次为毛茶>轻火>中轻火>中火>高火;以丹桂清除率(13.02%)减幅最大,雀舌的清除能力最强。相关性分析表明,茶多酚、黄酮含量与DPPH·清除率呈极显著正相关(P<0.01),水浸出物、氨基酸和咖啡碱含量与DPPH·清除率呈显著相关性(P<0.05)。

Wuyi rock tea (Jin Guanyin,Dan Gui,Mei Zhan,Que She,Qi Dan) were tread with different baking times to evaluate it’s corresponding changes on main biochemical components,sensory quality and antioxidant activity.Results showed that,with the increase of baking time,the contents of water extract,free amino acid,tea polyphenols,caffeine and flavonoids decreased in the five rock tea species comparing to their material tea,and the greatest reduction was in water extract of Jin Guanyin (11.32%),polyphenols of Dan Gui (16.86%),amino acids of Qi Dan (40.95%),flavonoids of Mei Zhan (13.57%) and caffeine of Qi Dan (22.31%),respectively.Meanwhile,by sensory evaluation,all the five Wuyi rock tea species showed that sensory quality was improved,and among them,the rock tea treated by middle fire got the highest sensory score.The ability of Wuyi rock tea to scavenge organic free-radicals (DPPH) decreased as the degree of baking increased.The radical scavenging capacity order was material tea>light fire baked tea>medium light fire baked tea>medium fire baked tea>high fire baked tea.The greatest reduction was Dan Gui (13.02%) in clearance ability,and Que She’s scavenging capacity was the best.The correlative analyses showed that the scavenging capacity to DPPH was highly significant correlation with tea polyphenols and flavone contents (P<0.01),and significant correlation with water extracts,caffeine and free amino acid contents (P<0.05).