This study has shown that the PLA coating on the inside of the cardboard tray has a very significant effect on the adsorption of ethylene and water vapour, and can be used in active packaging systems to regulate both factors. In the early stages of storage, there is a little production of water vapour and a high production of ethylene, which is adsorbed in the PLA layer. In later stages, ethylene production in tomatoes falls and water vapour production increases, so that ethylene may be exchanged for water vapour in the PLA layer, allowing the progressive exit of small amounts of ethylene through the wall of the thin LDPE film. In conclusion, passive modified atmosphere packaging in combination with active packaging using PLA-coated cardboard trays wrapped with thin LDPE film significantly extends the shelf life of fresh tomatoes. This is a good solution for fresh tomato packaging compared with packaging systems using trays wrapped with perforated films because the active package is closed and microbial recontamination by pathogens is avoided. Therefore, microbial safety is better, while
ethylene concentration inside the package is controlled at the same time. In addition, with the studied active packaging system, there is a considerable saving of energy during the
storage and distribution of fresh tomatoes, as the storage temperature is 20 °C, much higher than the storage temperatures usually used with MAP