galaktouronihappo

Galaktouronihappo, also known as galacturonic acid, is a uronic acid derived from galactose. It is a fundamental component of pectin, a polysaccharide found in the cell walls of plants. Pectin plays a crucial role in plant structure, providing rigidity and acting as a cementing agent between plant cells. Galacturonic acid is characterized by the presence of a carboxyl group (-COOH) at the C-6 position of the galactose molecule, whereas galactose itself has a primary alcohol group (-CH2OH) at this position. This oxidation of the terminal carbon atom is what distinguishes it as a uronic acid.

In its pure form, galacturonic acid is a white crystalline solid. It can exist in both alpha and beta anomeric forms, similar to other sugars. Its chemical structure allows it to form ester linkages with other galacturonic acid residues or with methanol, creating the characteristic highly branched structure of pectin. The degree of esterification, which refers to the proportion of carboxyl groups esterified with methanol, significantly influences the gelling properties of pectin. This property is widely utilized in the food industry, where pectin is used as a gelling agent, thickener, and stabilizer in products like jams, jellies, and yogurts. Beyond its role in pectin, galacturonic acid is also a component of other complex carbohydrates and has been investigated for its potential biological activities.