The apples used in this study (Golden delicious) come from local supermarkets. Apples were initially washed with chlorinated
water (150 ppm of active chlorine for 3 min) to prevent surface
contamination (Wardowski and Brown, 1991) and after peeling
and cut in slices of about 1 cm of thickness. The polymeric films
are cut in the rectangle about 7.0 cm lengths and 10.0 cm widths
and are exposed to UV rays (30 W UV lamp) for 15 min before
packaging. Subsequently one apple slice is packed in the prepared
biofilm, stored at 4C and weighed every 24 h, until steady weight.
The weight of all samples is relative to the total weight of apple
slice and package; inFig. 1the change in the water content (%) is
reported during 16 days of de-hydration (Burdon and Clark,
2001) and the data are mean value of triplicate experiments.
The sealing procedure is tailored on the polysaccharide nature
of the material, that cannot be melt sealed. So a solution of polyvinyl-alcohol is brushed on the edges of the package; then the package is folded allowing the two wet edges to touch and to dry under
pressure