Abstract:

The extraction and antioxidant activity of polysaccharides from Guichang kiwifruit pulp or pericarp were
investigated in this work. The optimization of the extraction parameters was investigated by using orthogonal array design.
Polysaccharide content was determined by the anthranone-sulfuric acid method. The antioxidant activities of Guichang kiwifruit
polysaccharides were tested by pyrogallol autoxidation and Fenton’s oxidation reaction. The results showed that the optimum
extraction conditions for kiwifruit pulp polysaccharides were found to be 2 h extraction at 80 ℃ with a solid-to-solvent ratio of
1:35 (g/mL) performed three times, and those for kiwifruit pericarp polysaccharides were determined as follows: three extraction
cycles at 70 ℃ each for 2 h at a solid-to-solvent ratio of 1:25 (g/mL) . Under the optimized conditions, the yield of polysaccharide
extracted from kiwifruit pulp and pericarp reached 1.74% and 1.16%, respectively. The polysaccharides from kiwifruit pulp and
pericarp both had strong scavenging effects on superoxide anion and hydroxyl radicals with half inhibitory concentration (IC50) of
12.4 and 41.3 μg/mL for pulp polysaccharides and 84.1 and 50.8 μg/mL for pericarp polysaccharides, respectively.

Key words: Guichang kiwifruit, pulp, pericarp, polysaccharide, extraction process, antioxidant activity