Structural characterisation, physicochemical properties and antioxidant activity of polysaccharide from Lilium lancifolium Thunb.

A novel polysaccharide fraction (LP2-1) was isolated and purified from the edible bulbs of Lilium lancifolium Thunb. by DEAE cellulose chromatography and Sephacryl S-400 size-exclusion chromatography. The structural characterisation, physicochemical properties and antioxidant activity of LP2-1 were investigated. The results showed that LP2-1 had an average molecular weight of approximately 8.52×10(3)kDa and was mainly composed of l-rhamnopyranose, d-arabinofuranose, d-glucopyranose and d-galactopyranose in the molar ratio of 1.88:2.13:1.00:2.50, and major functional groups of LP2-1 were COO and OH. The viscoelastic properties of LP2-1 systems exhibited a gel-like behaviour, with storage modulus higher than loss modulus, and both moduli increased with increasing Ca(2+) concentration. In addition, LP2-1 had DPPH and hydroxyl radicals scavenging activities, and also had the strong reducing power and chelating activity on ferrous ion. These results suggest that LP2-1 has good antioxidant activity and can be used in food industry.