Abstract

TO IMPROVE THE QUALITY OF BLACK TEA BY TANNASE ENZYMATIC TREATMENT USING ENTEROBACTER CLOACAE

Dr. Y. Thangam*, K. Jaisankar, M. Aruna and Dr. R. Sowdeshwari

Abstract

The word tannin is very old and reflects a traditional technology. "Tanning" (waterproofing and preserving) was the word used to describe the process of transforming animal hides into leather by using plant extracts from different plant parts of different plant species. Plant parts containing tannins include bark, wood, fruit, fruit pods, leaves, roots, and plant galls. Tannins are phenolic compounds that precipitate proteins. Tannase hydrolyses tannic acid completely to gallic acid and glucose through 2, 3, 4, and 6, tetragalloyl glucose and two kinds of monogalloyl glucose. Tannase has catalytic activity to remove gallic acid moieties from tannins and the polyphenols from tea extracts which results in coldwater soluble products. The treatment of tea with tannase enhances the natural levels of epicatechin and gallic acid which in turn favours the formation of epicatechin flavic acid.

Keywords: Black tea, Tanin, Tannase enzyme, Gallic acid, Enterobacter cloacae.