Jumat, 19 Oktober 2012

biosynthesis of catechins from tea leaves

Tea polyphenols or catechins are often referred to as a unique substance because it is different catechins found in other plants. Catechins in tea are not tan and do not adversely affect the digestion of food. Tea catechins to be antimicrobial (bacteria and viruses), antioxidants, antiradiasi, strengthen blood vessels, launched urine secretion and inhibits the growth of cancer cells.
Catechins are the main groups of substances of green tea the most influential of all the components of tea. In processing, these colorless compounds, either directly or indirectly, are always associated with all product properties of tea, the flavor, color and aroma.
Catechins are the largest group of components of leaf tea, especially the catechins flavonoids. Tersitesis catechins in tea leaves through the melanic and sikimat acid. While galik acid derived from an intermediate product produced in sikimat acid metabolic pathways.


 
Biosynthetic pathways of leaf tea catechins

Catechin tea plant is divided into two main groups, namely proanthocyanidin and polyester. Green tea catechins are composed mostly or compounds - compounds catechin, epicatechin, galokatekin, epigalokatekin, epicatechin gallate, galokatekin error, and error epigalokatein. The concentration of catechins is highly dependent on the age of the leaf. Buds and first leaves of the richest catechins error. Catechin levels vary depending on the varieties of the tea plant. katekni extraction from tea leaves shown in this chart: 
 
Mechanical extraction of catechins from tea leaves