2.3. Coating
The coating solution was prepared by dissolving 0.1%
(w/v) of chitosaninanaqueous solution of1% acetic acid (v/
v). The coating of the sheets was carried out by two
methods: (i) spraying the solution onto the sheet; and (ii)
immersing the sheet in the chitosan solution. The cross-inking was carried out with an aqueous solution of 0.5%
glutaraldehyde (v/v) for spraying in process (i) and
immersion in process (ii), and the samples were then dried
with hot air. Coated sheets were kept in an air flow at room
temperature for 24h. In some cases, as previously mentioned, the procedure for the deposition of the chitosan
film and subsequent cross-linking was repeated, these
samples being denoted as
“
Spray (2x)
”
and
“
Immersion
(2x)
”
. The uncoated sheets are considered as the control.