Pectin is a natural polysaccharide that forms a colloidal gel in plants to confer rigidity and to help regulate water transport between cells. It is used as an additive in cooking to "set" jams. Pectinase is an enzyme that breaks pectin down and prevents it from gelling.
The presence of pectin in fruit can retain liquids, so pectinase is often used in commercial processes to improve the juice yield.
SOURCE: Aspergillus niger