Pectins

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.