Use and method of chitosan oligosaccharide in fresh preserving

The invention discloses the application of chitosan oligosaccharide in keeping fruits fresh. The invention also discloses a method which uses the chitosan oligosaccharide to keep fruits fresh. The fruits in the green ripe stage are put in the solution of the chitosan oligosaccharide with the concentration of 0.05-15g/L for 5 to 20min or put in the vacuum degree of 0.01-0.08 MPa for 2-15min, and then are dipped under ordinary pressure for 2-15min, later are taken out and dried, put in a refrigeratory for storage. The invention can, by using the chitosan oligosaccharide, obviously reduce the occurrence degree of plant diseases after the fruits are picked and prolongs the storage period and the shelf period of the fruits; secondly, the invention has the advantages of simple method, low cost, and easy popularization and application; furthermore, the chitosan oligosaccharide used by the invention belongs to a natural extract, has no pollution to the environment and no health hazards to human beings, and is environment-friendly after being applied to fresh-keeping of fruits.