t In order to extend the shelf life of fresh tomatoes
using biodegradable materials, an active microcorrugated
cardboard tray package was tested for use with fresh Cherry
tomatoes (Lycopersicon esculentum var. cerasiforme). Active
packaging characteristics were achieved by coating the
interior surface of the cardboard tray with polylactic acid
(PLA; 3% w/v) and, after filling with tomatoes, the tray was
wrapped with a low-density polyethylene (LDPE) film of 70
or 20 μm thickness and hermetically heat sealed. Uncoated
trays were used as control. The trays of tomatoes were
stored at 20±0.5 °C and 55±2% relative humidity, for
30 days, and the ethylene concentration in the package
atmosphere was measured periodically as an indicator of
ripeness. The following fruit quality parameters were also
studied: weight loss, surface colour, microbial count, firmness,
soluble solids and pH. It was demonstrated that the
capacity of PLA to adsorb ethylene and water vapour and
the thickness of the LDPE film were decisive for controlling
the ethylene concentration of the package atmosphere and for
preventing condensation of water vapour on the fruit and film.
The active packaging configuration and storage conditions
used preserved fruit quality for a month, thus extending the
useful life of the tomatoes and saving refrigeration costs