Pectin is a polysaccharide starch that resides in vegetables and fruits. The apple dedicates up to 20% of its flesh to pectin. Apple pectin powder -- a vegan alternative to powdered gelatin – is used as a thickening agent in making jams, jellies and marmalades and to produce a clear sugary glaze for tarts and pastries. As one of the richest sources of soluble fiber, bulk apple pectin powder is also encapsulated as a dietary supplement.