Films derived from soya by-products were successfully prepared and transparent films with excellent UV barrier properties were obtained.
The best results were obtained at pH 10, at which the protein unfolding is better to promote protein-plasticizer interactions, as shown by changes in the relative intensity of the bands corresponding to amides in infrared spectra.
Moreover, gloss was low and contact angle high, indicating that the surface is rough and hydrophobic, respectively.
According to the environmental assessment, results revealed that environmental burden associated to soy protein films should be reduced.
Therefore, future improvements in the extraction processes together with an optimization of the manufacture would help to increase environmental advantages of these materials that could be potential sustainable alternatives to petroleum-based films.