Isolation and identification of polysaccharides from Pythium arrhenomanes and application to strawberry fruit (Fragaria ananassa Duch.) preservation

In this study, we extracted exopolysaccharides from Pythium arrhenomanes and purified them to obtain three polysaccharides (PEPS-1, PEPS-2, PEPS-3). The composition of these polysaccharides was determined. PEPS-2 and PEPS-3 showed outstanding antioxidant activities. PEPS-2 was chosen as a polysaccharide-based coating for strawberry fruit, and its effects on postharvest preservation of the fruit were determined. Strawberries coated with PEPS-2 exhibited significant delay in decay index and lower malondialdehyde, higher soluble solids content, anthocyanin content and vitamin C content, and greater DPPH radical-scavenging activity than uncoated control fruit. The developed method could be beneficial for improving the shelf-life of strawberries.