**1.2 Pectinase**

Pectinase is a complex group of enzyme that catalyzes the degradation of pectin polymer [23]. Pectinase has wide range of applications in fruit juices preparation, textile processing, papermaking, pectin containing wastewater treatment, degumming of plant's bast fibers, wine clarification, oil processing and coffee and tea industry.

### *1.2.1 Classification of pectinase*

On the basis of pectin degrading mechanism, the pectinase enzymes are classified into polygalacturonase, pectin lyase and pectin esterase (**Figure 3**).

#### *1.2.1.1 Polygalacturonase*

Polygalacturonase catalyzes the hydrolysis of pectin polymer into D- galacturonic acid monomer by addition of water molecules in α-1, 4 glycosidic linkages. Polygalacturonase is the most extensively studied enzyme among different pectinolytic enzymes and further classified into exo-polygalacturonase and endo-polygalacturonase by breaking of external and internal glycosidic bond of polymer chain, respectively.
