Abstract:Nanomaterials have been widely used in many fields for their antibacterial and antiseptic effects, but their antibacterial properties can not be brought into full play due to the aggregation of particles. The composite of nanoparticles and polymer materials can prevent the aggregation of nanoparticles to a certain extent, so turning nanomaterials into polymer composites for the applications in the field of antisepsis and preservation of agricultural products will have a broad prospect. In this study, pathogenic fungi were isolated from Dongzao jujube by the tissue isolation method, and their pathogenicity was verified by the Koch's law. The compound preservative was prepared by mixing nano-TiO2 with the substrate, sodium carboxymethyl cellulose. The plate bacteriostasis experiment was carried out on the isolated pathogenic bacteria, and the inhibition mechanism was preliminarily explored. The results showed that the isolated Dongzao jujube fruit rot was Fusarium sp. In vitro experiments showed that the nano-TiO2 compound preservative solution inhibited the growth of Fusarium sp. The minimum inhibitory concentration and minimum bactericidal concentration on pathogenic spores were 9.77×10-3 g/L and 39.06×10-3 g/L respectively. The nano-TiO2 preservative solution inhibited the growth of pathogen mainly by destroying the fungal cell membrane; the research on the preservation of Dongzhao jujube confirmed that the preservative solution can significantly reduce the rate of fruit rot and delay the reduction of the Vc content in the fruit. In conclusion, the composite solution of nano-TiO2 and CMC-Na can be used as an effective antibacterial means to control Fusarium in the postharvest jujube fruits, which provides effective technical support for prolonging the shelf-life of dongzao jujube.
