pectin

A polysaccharide extracted from the cell walls of plants, especially of fruits; under acidic conditions it forms a gel. It is often used in processed foods, especially jellies and jams where it causes thickening (setting).

Pronounced as (IPA)

/ˈpɛktɪn/

From French pectine, coined in the 1830s by Henri Braconnot, from acide pectique "pectic acid", from Ancient Greek πηκτικός (pēktikós, “curdling”), from πηκτός (pēktós, “curdled”), from πήγνυμι (pḗgnumi, “stiffen”).