Research Preparation And Application Of Edible Antibacterial Film

As environmentally-friendly products,two kinds of edible antibacterial films were made to oppose the bacterial invading.Two new films were coated on the fresh fruit for preservation research.Secondly,an antibacterial film containing bio-pesticide Liangguoan was made and coated on Xiahei grape for field experiment.The edible quality of grape treated with film and the grape with normal chemical pesticide spraying were determined.Finally,taking Escherichia coli and Staphylococcus aureus as indicator bacterias to determine the minimum inhibitory concentration,observe cell morphology,bacterial mortality,bacterial conductivity,nucleic acid content and ATP content changes.The antibacterial mechanism of biopesticide capsule was studied.The following are the main findings:(1)The optimal amount of cinnamon essential oil to tapioca starch antibacterial film was 0.68 m L to 100 m L.The addition of cinnamon essential oil improves the mechanical properties of the tapioca starch film,and reduces the light transmittance and hygroscopicity of the film,and improve preservation ability to a certain extent.(2)Compared to chitosan membrane,the barrier performance of the konjac antibacterial film is slightly weaker,and the two are similar in light transmittance,the toughness of the film is improved,and the preservation ability is enhanced.(3)The results of field experiment showed that the vitamin C(VC),grain weight,fruit diameter and hardness of the grape coated with capsule antibacterial film were increased,and the difference of flavonoids,acidity,solid content and reducing sugar was not obvious,indicating that the film treatment has no effect on edible quality of Xiahe grape,and the antibacterial film can replace the chemical pesticides.(4)The antibacterial mechanism of liangguoan showed: the minimum inhibitory concentration of Liangguoan against Staphylococcus aureus and Escherichia coli was 20 mg/m L and 40 mg/m L,respectively;Liangguoan combined with garlic oil were bacteriostatic agents against Staphylococcus aureus and Escherichia coli.The minimum inhibitory concentrations were 0.3125 mg/m L and 10 mg/m L,respectively.The morphology of Staphylococcus aureus and Escherichia coli cells changed by scutellaria,and the cell conductivity and nucleic acid content increased,ATP content.decline.The bacterial mortality rate was 89.6% and 92.3%,respectively.The compounding agent of Liangguoan and garlic oil showed synergistic effects in the antibacterial experiments of Staphylococcus aureus and Escherichia coli.The antibacterial agent was 7 in p H,and the antibacterial effect against Staphylococcus aureus was the best when UV irradiation for 0 min.The antibacterial effect on Escherichia coli was the best when the p H was 8 and UV irradiation for 0 min.Through the detection of bacterial growth curve,light microscopy,and leakage of cell contents,the results were consistent.It indicated that the antibacterial effect of Liangguoan compounding agent is better than that of Liangguoan alone,and the antibacterial effect of Liangguoan on E.coli is better than that of Staphylococcus aureus.