Effect of Polymethoxy Flavones from Citrus Peels on Antibacterial and Fresh-Keeping of Red Grape

The antibacterial effect and protective role of polymethoxy flavones from Citrus peels on storage quality of red grape were investigated in the experiment. The antibacterial effect was studied by measuring the antibacterial circle diameter and MIC. The influence on red grape in the storage process was studied by measuring the fruit firmness, respiration intensity, activity of polyphenol oxidase (PPO) and other indicators. The results of antibacteial experiments showed that PMFs inhibited the growth of bacteria. And the data showed the dose-dependent. The results of storage showed that different concentrations of PMFs had good fresh-keeping effect on the red grapes, as compared with control group. And 4.0 mg/mL PMFs had the best effect. Compared with the control group, the soluble solids and hardness had no change after 4.0 mg/mL PMFs treatment at the 12th day, while V_C loss, decay rate and shattering rate were decreased. Respiratory rate, MDA content and PPO activity increased slowly compared with control group, while TA content decreased slowly. The results indicated that PMFs from Citrus peels could improve the storage quality of red grapes as compared with control group. In conclusion, the data showed that PMFs from Citrus peels could act the good fresh-keeping effect on red grape and have the potential to be a kind of natural food preservative.