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Two antimicrobial agents of organic salicylic acid （SA） and inorganic nanosized titanium dioxide （TiO2） were added into polylactic acid （PLA） respectively to prepare two different biodegradable packaging films. The antimicrobial properties of PLA‐based films were then characterized and the film preservation effect on fresh vegetables had been exampled by evaluating the external appearance, headspace gas concentration, weight loss rate, decay rate and ?a/b values of Chinese rape. The results showed that the antimicrobial rate of PLA/4%TiO2 film was 91.3% against Staphylococcus aureus and 90.8% against Escherichia coli . In the case of PLA/6%SA film, its antimicrobial rate was 97.3% against S. aureus and 93.1% against E. coli . These two antimicrobial films were seen to obviously reduce the respiration rate of Chinese rape and exhibit lower decay rate and higher ?a/b values of Chinese rape than those packaged in pure PLA bag, resulting in the extended shelf life for stored Chinese rape. These satisfactory performances suggest that the PLA‐based antimicrobial films could be potentially suitable for the preservation of green vegetables.
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