In order to study TPS bags tightness, films barrier properties
were determined. Moreover, a qualitatively evaluation was per-
formed by visual analysis and a photographic register of thermo-
sealed bags containing cherry tomatoes (Lycopersicon esculentum).
Water vapor permeability (WVP) was performed using two
different standard methods. According to ASTM E96-00 standard
method, WVP was determined gravimetrically. Films with an
exposure area of 38.48 cm2were fixed on test cells containing a
desiccant (calcium chloride). Test cells were placed in chamber
with controlled temperature (25?C) and RH (50%). After steady-
state conditions were reached, weight of test cells was measured
every 1 h over 1 day. Water vapor transmission rate (WVTR) was
determined using equation (1).