Abstract: Pectic polysaccharides are a group of polysaccharides composed of D-galacturonic acid and neutral saccharides, and they widely exist in plant cell walls. Pectic polysaccharides are endowed with multifunctional properties such as direct effects on plant tissue integrity and firmness and the self-protection of plants against phytopathogens, gelling ability, emulsifying capacity and emulsion stability, thickening ability and health benefits including regulating the intestinal microbiota, alleviating hyperlipidemia and prevent colon cancer. The fine structures of pectic polysaccharides include pectic domains such as homogalacturonan, rhamnogalacturonan-I, rhamnogalacturonan-II and/or xylogalacturonan, which are covalently inter-linked to form pectin complexes. This review focuses on the depiction of the structural domains of pectic polysaccharides with the aim of providing the latest information on the structural models of pectic polysaccharides.

Key words: pectic polysaccharides, structural domain, fine structure, pectinase, covalent connection