Research On Nano-antibacterial Keeping Fresh Agents And Applications On The Fruits And Vegetables

Nano-silicon dioxide particles was treated with anionic surfactant detergent SDS to prepare chitosan/nano- silicon dioxide composite films by solution method,the films obtained were characterized by FTIR and TEM. The viscosity,thickness,percent water absorption, optical trasmittance,the measurements of mechanical properties and antibacterial activity of composite films were compared to the film of chitosan.It was found that there was hydrogen bonding interactions between chitosan and silicon dioxide nanoparticles.The proper content of silicon dioxide nanoparticles can make up for the mechanical properties,and also enhanced the antibacterial activity of composite films.Orthogonal test design was used for the storage of Fuji apples under the room temperature after 4 months, and the indexes of glucose were analyzed statistically.The ingredients of best selected coating agent were: chitosan1.5%, nano-silicon dioxide 0.5%, 1,2-propanediol 1% and Polyvinyl alcohol 1.5%. Results show that there were relatively higher contents of firmness,total sugar,vitamin C, organic acid and soluble solid content than the control, the accumulation of carbon dioxide was not higher than the comparison.The preservation period is prolonged effectively.Six kinds of coating were prepared for the storage of Jinqiu pear under the room temperature and the refrigeration (0~4℃).The weightlessness rate, degree of hardness, soluble solid content, the total acid, the cell membrane penetrability, the total sugar, the decay rate and vitamin C of Jinqiu pear were determinated after stored 60d to the room temperature, as well as the refrigeration (0~4 ℃) stored 90d.As we all know that, the weightlessness rate and decay rate were the most important appraisals target which affects the value of the fruits and vegetables.It was found that weightlessness rate and decay rate of Jinqiu pear which in different coated and under different storage condition were remarkably lower than the corresponding comparison (CK). Among them, the CTS2 was the best, which included 0.3% nano-silicon dioxide particles can prolong the storage of Jinqiu pear for one month. Comprared to CK, the distinguishe of the firmness, soluble solid contents, the total acid, cell membrane penetrability, total sugar and Vitamin C of Jinqiu pear by defferentiy coated and under different conditions was not remarkable. Overall, the results show that, the low temperature was much better than the room temperature for the storage of Jinqiu pear.