6种中非不同紫芽茶品质特性及其抗氧化活性研究

Study on quality characteristics and antioxidant activities of 6 kinds of China-Africa different purple-bud tea

中文关键词:  紫芽茶  品质特性  抗氧化活性  加工工艺  生化成分

英文关键词:purple-bud tea  quality characteristics  antioxidant activity  processing technology  biochemical components

中文摘要:

      目的 比较中国与非洲肯尼亚不同紫芽茶品质特性及抗氧化能力。方法 对来自中非的6种紫芽茶进行感官审评, 并比较其生化成分含量, 通过测定1,1-二苯基-2-三硝基苯肼自由基(1,1-diphenyl-2- picrylhydrazyl radical, DPPH·)、2,2’-联氮-二(3-乙基-苯并噻唑啉-6-磺酸)二铵盐阳离子自由基[2,2’-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt cationic radical, ABTS+·]的清除率和总抗氧化能力, 评价6种不同紫芽茶体外抗氧化活性, 并分析体外抗氧化活性与生化成分间的相关性。结果 感官审评结果表明, 6种茶样的感官品质综合得分由高到低的顺序为: 赤道富硒紫毫>紫娟绿茶>紫娟白茶>紫娟红茶>赤道富硒紫茶一级>赤道富硒紫茶二级。生化成分分析表明, 以云南‘紫娟’品种为原料加工成的紫芽茶随着茶叶发酵程度的加深, 儿茶素、茶多酚和花青素含量都显著降低, 水浸出物含量逐渐增加, 其中, 紫娟绿茶的花青素和儿茶素总量最高。不同原料等级制成的3种赤道富硒紫茶中, 茶多酚、咖啡碱及儿茶素总量随着原料嫩度的降低而逐渐降低, 其中, 赤道富硒紫毫茶的茶多酚和游离氨基酸含量最高。抗氧化能力测定结果显示, 中非紫芽茶均具有抗氧化活性, 其中赤道富硒紫毫茶的抗氧化能力最强, 具有较强的DPPH·、ABTS+·清除能力和总抗氧化活性, 紫娟红茶较低。相关性分析表明6种紫芽茶的抗氧化活性与茶多酚和儿茶素含量均呈极显著正相关(P<0.01), 相关系数分别为0.842和0.752; 与水浸出物含量以及咖啡碱含量呈显著的负相关性(P<0.05), 相关系数分别为?0.532和?0.803。结论 本研究的6种中非不同紫芽茶中, 白茶和绿茶的抗氧化性较好, 红茶的抗氧化性最弱。其中, 赤道富硒紫毫的感官品质优良, 品质化学成分含量丰富, 抗氧化能力最强。

英文摘要:

      Objective To compare the quality characteristics and antioxidant capacities of different purple-bud tea from China and Africa Kenya. Methods The sensory evaluation of 6 kinds of purple-bud tea from Yunnan and Kenya was carried out, and their biochemical components were compared. The antioxidant activities of 6 different of purple-bud tea varieties in vitro were evaluated by measuring the clearance rates of 1,1-diphenyl-2- picrylhydrazyl radical (DPPH·), 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ammonium salt cationic radical (ABTS+·) and total antioxidant capacity, the correlation between antioxidant activity and biochemical components in vitro was analyzed. Results The sensory evaluation results showed that the sensory quality comprehensive scores of 6 kinds of tea samples ranked from high to low was follows: Equatorial-selenium-rich-purple-tip tea>Zijuan green tea>Zijuan white tea>Zijuan black tea>equatorial-selenium-rich-purple tea grade I>equatorial-selenium-rich-purple tea grade II. Biochemical component analysis showed that the content of catechin, tea polyphenols and anthocyanins in different kinds of tea processed with Yunnan ‘Zijuan’ variety as raw material decreased significantly, and the content of water extract gradually increased with the deepening of tea fermentation. Among them, the total amount of anthocyanin and catechin in Zijuan green tea was the highest. In 3 kinds of equatorial-selenium-rich-purple tea made of different raw material grades, the total amount of tea polyphenols, caffeine and catechin gradually decreased with the decrease of raw material tenderness. Among them, the content of tea polyphenols and free amino acids in equatorial- selenium-rich-purple -tip tea was the highest. The results of antioxidant capacity test showed that both Chinese and African purple-bud tea had antioxidant activity among which equatorial-selenium-rich-purple-tip tea showed the highest antioxidant capacity with strong DPPH·, ABTS+· scavenging ability and total antioxidant activity, while Zijuan black tea was lower. Correlation analysis showed that the antioxidant activities of 6 kinds of purple-bud tea showed a highly significant positive correlated (P<0.01) with the content of tea polyphenols and catechin, with correlation coefficients of 0.842 and 0.752, respectively; and a significant negative correlation (P<0.05) with the content of water extracts and caffeine, with correlation coefficients of ?0.532 and ?0.803, respectively. Conclusion Among the of 6 kinds of purple-bud tea from China and Kenya in this study, white and green tea has better antioxidant ability, black tea has the weakest antioxidant property. Among them, equatorial-selenium-rich-purple-tip tea has excellent sensory quality, rich chemical components and the strongest antioxidant capacity.