Preparation, deproteinization, characterisation, and antioxidant activity of polysaccharide from cucumber (Cucumis saticus L.)

Preparation, deproteinization and antioxidant activity of polysaccharide from cucumber (Cucumis saticus L.) were investigated. The crude cucumber polysaccharide was extracted by hydrothermal method. It showed that the trichloroacetic acid (TCA) method had the higher deproteinization percentage, but a little higher polysaccharide loss percentage than the CaCl2 method. The cucumber polysaccharide is linked by the β-glycosidic linkage. It consisted of d-glucose, d-mannose, d-galactose, l-rhamnose, d-xylose, l-arabinose, d-glucuronic acid, and d-galacturonic acid. Their mole ratio was 6.00:4.03:8.31:2.82:2.75:6.60:1.05:5.79. Moreover, it proved that the cucumber polysaccharide had high scavenging ability to superoxide anions.