Fig. 3 illustrates the behavior of the solubility coefficients (b) of
water in the films, showing that the values of this coefficient
strongly depend on the range of the air relative humidity (water
activity of the film). Although few works had investigated the
influence of this coefficient in the water vapor permeability of
starch and protein based films (Moore et al., 2006; Mu¨ ller et al.,
2008), the behavior of this coefficient is determinant in the water
permeation processes, as discussed in the following.