Study Of Preservative And Fresh-Keeping Effect Of Clove Extract On Friut

Postharvest diseases of fruits cause major losses, these diseases are primarily controlled by application of synthetic fungicides. Alternative methods are needed because of concerns about environmental contamination and human health risks associated with fungicide residues and because the widespread use of these chemicals in commercial packinghouses has led to the proliferation of resistant strains of the pathogens. Plant extracts have shown great potential as an alternative to synthetic fungicides for the control of postharvest decay of fruits and vegetables.Seven botanic materials were extracted with ethanol and the rough extracts were tested for their inhibitory activity against fruit rot-causing fungi. The result shows clove extract has good inhibitory effect against M.frucigena, Botrytis.pers.exfr.and P.digitatum Sacc. The Minimal inhibitory concentrations(MIC) of clove extract was tested on the 3 fungi above. The result shows the MIC on P.digitatum Sacc was 6.25mg/mL, the MIC on Botrytis.pers.exfr was 25 mg/mL, and the MIC on M.frucigena was 6.25 mg/mL. The experiment of the extracting method for clove shows 80%ethanol is suitable solvent and 48h extracting time is good. The inhibitory activity was steady below 80℃and reduced in 100℃. The in inhibitory activity can retain in pH3～10.The preservative and fresh-keeping experiment results of clove extract on red-global grape shows that this extract have really significant fresh-keeping effects. Compared to the control testing, this preservative liquid can reduce respiratory intensity and retain the firmness of the grapes. The result shows it can reduce the loss of SSC, TA, the rot rate, ratio of berry drop and the MDA content. The result also shows this preservative liquid can enhance the activity of PPO, POD and PAL.The matching liquor was made of clove extract and chitosan, using this liquid as preservative on grape. The result shows this matching liquid can reduce the brown index of grape spike and can lower the respiratory intensity of the grapes. The result also shows this matching liquid can remain the firmness of grapes and it can control the consumption of the nutrient of grapes. The result shows that 1% clove extracting liquor+1%chitosan and 2%clove...