Abstract:
Plant cell wall is predominantly composed of complex structural polysaccharides such as celluloses and hemicelluloses. Polysaccharides of the primary cell wall components of plant are cellulose, hemicelluloses such as xyloglucans, mannans, galactomannans, glucomannans, laminarin, glucoronoarabinoxylans, arabinoxylan, etc. Mannans are the polysaccharides with a backbone chain of β- (1-4)- linked mannose units. They constitute a major portion of hemicelluloses in hardwoods. The major distribution of mannan polysaccharides substituted with galactose and glucose units in plant hemicellulose reservoir is abundant in nature. Carob galacomannan from Ceratonia silique plant contains β-(1-4)-D-mannan backbone (78%) and α-(1-6)- linked galactose (22%) single units, whereas guar gum (from endosperm of guar seeds) backbone is a linear chain of β-(1-4)- linked mannose residue to which galatose residues are (1-6)-linked at every second mannose forming short side –branches. Glucomannan from Amorphophallus konjac is a water soluble polysaccharide that is considered as a dietary fiber. The component sugar units in kojac glucomman are β-(1-4)-linked D-mannose and D-glucose residues in a molar ratio of 1.6:1.
