At the same time,
ethylene-producing microorganisms may cause the supplementary
production of ethylene, as might the tomatoes due
to microbial stress, making ethylene release through the
thick LDPE film wall more difficult. The lowest value
detected for ethylene concentration in the PLA-coated trays
wrapped with thick LDPE film was 0.54 μL/L in the second
week of storage, when the condensation of water vapour
was not perceptible. Nevertheless, it may be necessary to
further reduce ethylene to increase the shelf life since there
is biological action on tomato at concentrations of only
0.1 μL/L (Wills and Warton 2000). In the case of PLAcoated
cardboard trays wrapped with thin LDPE film
(20 μm), the ethylene concentration was always five- to