pectins, carbohydrate polymers made up of galacturonic acid units which have the important function of ‘gumming’ plant cells together. The group is diverse and includes pectic acid, hemicelluloses, and gums; the associated sugars are galactose, mannose, and arabinose. The pectin content of grapes increases steadily throughout ripening, reaching levels of about 1 g/l. Pectin is an important contributor to colloids. For the importance of pectin hydrolysing enzymes to winemaking, see enzymes.
