Beeswax-poly(vinyl alcohol) composite films for bread packaging.

The study aimed to improve the barrier characteristics of polyvinyl alcohol (PVA) film by adding beeswax (BW) and glycerin and by heat treatment in order to become a potential suitable material for bread packaging. XRD, FTIR and XPS showed new cross-links between PVA and beeswax demonstrating the composite nature of the film. TGA-DTA showed that glycerin reduced the dehydration and that the beeswax improved theirs thermal stability. The best PVA-beeswax film formula has water vapor permeability (WVP) only 7.5 times higher than that of polyethylene (PE), while PVA is 29 times more permeable. The correlation coefficients, linear (MLR) and stepwise (SR) regression modelling showed a direct correlation between WVP, solubility in food simulants, swelling capacity and biodegradability. Principal Component Analysis (PCA) demonstrated that the analyzed films have different behavior from PE, and among them the most similar is that of the PVA with 2 g of beeswax and no glycerin sample. This film type also showed efficiency in bread packaging.