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Post harvest treatment effects on the quality of green tea extract

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It has been reported that green tea extracts have many beneficial properties including antibacterial, antiviral, antioxidative, antitumor and antimutagenic activities. The protective effects of green tea have been assumed to be due to the powerful scavenging and antioxidative property of unpolymerised catechins and their gallates. The purpose of this thesis is to test the effects of a simple post harvest treatment method that can preserve the catechin content of green tea. The effects studied were the effects of waiting time between tea leaves picking and the steaming process designed to deactivate the polyphenol oxidase enzyme that could reduce the activity of the catechins. The waiting times tested were 1 hour, 12 hours, 24 hours and 36 hours. The effects of drying through a spray dry process were also tested. The effects studied were the decline of antioxidant activities using DPPH (2,2--1-hydracyl) which is a free-radical, and total catechin concentrations. The result shows that longer waiting time between leaves picking & the steaming process would lead to lower catechin total content and antioxidant activity. In addition, spray drying process also yielded the lowering of catechin content, which leads to lower antioxidant activity.

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Availability

B00436

(wh)

Available

Detail Information

Series Title

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Call Number

436

Publisher

: Swiss German University., 2008

Collation

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Language

English

ISBN/ISSN

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Classification

NONE

Content Type

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Media Type

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Carrier Type

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Edition

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Subject(s)

FT

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