Comparative Study On Antioxidant Activities Of Oolong Tea New Cultivars

Four direct evaluation methods on the antioxidant activity of Oolong tea was used firstly in this study.The designer took 6 kinds of tea leaves in progress as the subjects of the experiment,including Jinguiguanyin,Jinmeigui,Zimeigui,Zimudan,Ziguanyin,Chuntaoxiang.A comparative study on the antioxidant activity of Oolong tea for.different processing techniques and cultivars has been carried out,as well as the correlation with main biochemical composition.Comparative study on the antioxidant activity of Jingui guanyin showed that:dealing with different processing techniques the antioxidant activity of Jingui guanyin are presented as follows:fresh leaves>Made tea,including DPPH radical scavenging ability,reducing power,antioxidant capacity(for FRAP),inhibition of lipid peroxidation;Repeated fine manipulation with lesser extent is better than heavy extent fine manipulation with less times.The main results indicate that:(1)The scavenging rate of DPPH radical for fresh leaves was 63.10%,DPPH radical scavenging of made tea:processing B(61.30%)>processing C(50.00%)>processing A(44.68%);DPPH radical scavenging capability of Jinguiguanyin changed drasticly during fine manipulation process;(2)The antioxidant capacity of fresh leaves:803mg/g.Under the different processing process,the antioxidant capacity of made tea were:processing B(715mg/g)>processing A(740mg/g)>processing C(690mg/g);(3)The reducing capacity of fresh leaves:242mg/g;with the different process techniques,the reducing capacity of made tea were:C(231mg/g)>B(220mg/g)>A(205mg/g);(4)The inhibition rate of fresh leaves:65.70%with the different process techniques,the lipid per-oxidation inhibition of made tea were:C(52.06%)>B(50.50%)>A(44.37%).There is a significant distinction on the antioxidant activity Oolong tea fr esh leaves among different cultivars,and the change range is aslo obviously different during processing.The main results are as follows:(1)The DPPH radical scavenging rate of fresh leaves in different new cultivars were:59.04%? 77.63%,Ziguanyin>Chuntaoxiang>Zimudan>Zimeigui>Jinmeigui.After the same processing technique,the decline range of made tea as follows:6.11%?24.23%,Jinmeigui>Zimudan>Chuntaoxiang>Ziguanyin>Zimeigui;(2)T he antioxidant capacity of fresh leaves in different new cultivars were:833mg/g? 1094mg/g,Chuntaoxiang>Zimeigui>Ziguanyin>Jinmeigui>Zimudan.After the same processing technique,the decline range of made tea as follows:29m g/g-169mg/g,Chuntaoxiang>Ziguanyin>Jinmeigui>Zimudan>Zimeigui;(3)Th e reducing capacity of fresh leaves in different new cultivars were:266mg/g-315mg/g,Zimeigui>Ziguanyin>Chuntaoxiang>Zimudan>Jinmeigui.After th e same processing technique,the decline range of made tea as follows:15mg/g-72mg/g,Ziguanyin>Chuntaoxiang>Zimeigui>Zimudan>Jinmeigui;(4)The inhibition rate of the fresh leaves in different new cultivars were:43.33%? 58.50%,Ziguanyin>Zimeigui>Jinmeigui>Chuntaoxiang>Zimudan.After the same processing technique,The decline range of made tea as follows:1.67%-24.64%,Zimeigui>Ziguanyin>Zimudan>Jinmeigui>Chuntaoxiang.The main substance were water soluble matter,flavonoids,tea polyphenols and its oxidation products,such as TF and TR,.There existed some differences during different processing techniques and tea cultivars.