Characterization and application of novel composite films based on soy protein isolate and sunflower oil produced using freeze drying method

Abstract

Biocomposite films based on soy protein isolate (SPI) and sunflower oil (SO) were fabricated using freeze drying (FDM) as an innovative approach to formulate a fairly easy-to-apply way, moreover, results were compared with the classic film production method (CM). In FDM, SPI edible film solutions were prepared and dried using freeze drying, and then reconstituted to produce the films. The aim was to specify the effect of both using FDM and concentration of SO (0.05%, 0.10% and 0.15% (w/v)) on the characterization of SPI films via thermal, barrier and morphological analyzes. Reinforced mechanical and good barrier properties were achieved with FDM. By increasing SO content, an improvement of hydrophobic property of the films, a decrease in the swelling values, and a reduction in permeability was observed. The cakes which were wrapped with FDM films showed better textural results than either uncoated cake or the cakes wrapped with CM films.