Tannase enzyme: The most promising biocatalyst for food processing industries

Tannase (tannin acyl hydrolase, E.C.3.1.1.20) is an extracellular hydrolase enzyme that catalyzes the hydrolysis of aster and depside bonds in hydrolysable tannins or gallic acid esters, liberating glucose and gallic acid (GA). Tannase cleaves the ester linkages between galloyl groups present in various compounds such as epigallocatechin and epigallocatechin gallate that are present in green tea leaves. The enzyme could be obtained from many sources starting from prokaryotes to higher eukaryotes. Vital minutiae such as regulation pathways, catalytic characteristics and other properties remain unrevealed which limits its usage in large scale. This study essentially elicits the information on tannase substrates, mechanism, applications, and the recent trends in the purification of tannase.