Study On The Preservation Of Strawberry By Chitosan Radiolysis Products Film

Chitosan is used for non-toxic antistaling agent, attracts more and more attention recently. For the purpose of extending the storage period of fruits, chitosan can shape a micro-atmosphere environment through forming a semi permeable membrane on the surface of fruits, so that the breathing and other physiological and metabolic activity were slowed down. In addition, chitosan can kill effectively harmful microorganisms on the surface of a variety of fruits. The article focus on the refrigeration effectiveness of radiation degradation products of chitosan used in the preservation of strawberry fruits, and open up a new way for the retain freshness of strawberry.(1) This paper studied on the effect preservative of Strawberry coated with a series of different molecular weight chitosan which durations by radiolysis, sieving three kinds of better effective molecular weight(5.7×104Da,7.0×104Da,22×104Da), combined with the concentration, pH, acid solvent, the gelatin content. And writer designs the orthogonal test of four factors at three different levels was taken, test results show that when the recipe 1% viscosity average molecular weight of 7.0×104 Da, the pH of preservatives is 5, add 0.5% of gelatin has the best preservation effect. After a Study of the storage life of the coating strawberries by storage temperature and humidity, the results show that chitosan coating can increase the storage life of 2d at room temperature (20℃, HR89%～90%), and can extend the storage life of 3d at low temperatures (3～4℃, HR89%～90%).Compare with the full ripe strawberry, the medium well ones stay longer.(2) Base on the film formation and bacteriostatic, the article focus on the preservation mechanism of the products of radiation degradation of chitosan, the result show that chitosan possess great filmed, can form a preservative film on the surface of strawberry and restrain the growth of bacterial and epiphyte in the period of fresh storage. During the storage, after test and comparison the physiological and biochemical indexes of the films group and normal control, the author find out that films can slow down the decreasing speed of firmness of strawberry, protein, soluble glucose, ascorbic acid and ect., and by means of inhibiting effect on the peroxidase in the fruits can extent the storage preservation shell of strawberry.