A Study On Processing Technology Of Instant Tea With High Ester-catechin And EGCG Contents

In this study, using oolong tea, green tea, black tea as materials, the processingtechnique of instant tea with high ester-catechin and EGCG contents was investigated. Theresults were as followed:(1) The new processing technique of T-20and T-40improved the content ofester-catechin in instant oolong tea and green tea by13.58%～44.15%and25.71%～45.93%compared with that of control, respectively, meanwhile the content of EGCG was increasedby7.26%～46.47%and26.58%～47.25%respectively compared with that of control. Thecontent of ester-catechin in instant black tea was raised by14.08%～17.37%compared withthat of control. The technological effect of T-40was better than the one of T-20.(2) The new processing technique of LTSS improved the content of ester-catechin ininstant oolong tea, black tea, green tea, Jasmine tea by110.68%,269.21%,229.74%～308.23%and286.08%compared with that of control, respectively, meanwhile the content ofEGCG was increased by109.48%,267.31%,215.66%～306.41%,284.49%respectivelycompared with that of control. Statistical analysis showed that there was a significantdifference between the content of ester-catechin and EGCG in the instant tea processed byLTSS technique and the control.(3) Specific processing materials could improve the contents of ester-catechin andEGCG in the instant tea products. It was confirmed that the content of ester-catechin andEGCG in instant oolong tea (Dancong) processed by the material made in fall could beincreased than that in spring; the content of ester-catechin and EGCG in instant green tea(Meizhan) processed by the material made in summer could be increased than that in spring;there was significant difference in ester-catechin and EGCG content of instant tea made indifferent cultivars and the order followed Dancong>Maoxie>Tie Kuanyin.(4) As for the processing adjuvant, it was confirmed that the edible gallic-acid couldmarkedly raise the content of ester-catechin and EGCG in instant oolong tea produced by thevarieties of Dancong and Tie Kuanyin and black tea produced by the variety of Jinxuan, butdecrease the content of ester-catechin and EGCG in instant green tea produced by the varietyof Meizhan, as well as in instant black tea produced by the variety of Fuyun6; Edibleβ-cyclodextrin could significantly increase the content of ester-catechin and EGCG in instantgreen tea produced by the variety of Meizhan, but decrease the content of ester-catechin and EGCG in instant oolong tea produced by the variety of Dancong;L-ascorbic acid couldsignificantly improve the contents of ester-catechin and EGCG in instant oolong tea producedby the variety of Tie Kuanyin,but reduced the content of ester-catechin and EGCG in instantoolong tea produced by the variety of Dancong; Papain could significantly increase thecontent of ester-catechin and EGCG in instant green tea produced by the variety ofMeizhan,but different amounts of the addition had different effects on the contents ofester-catechin and EGCG in the instant oolong tea produced by the variety of Baxian.