Biodegradable Protein‐based Films and Their Properties: A Comparative Study

Biodegradable protein‐based films prepared from different protein sources [commercial bovine gelatine (CG), giant catfish skin gelatine (GG), soy protein isolates (SPI), fish myofibrillar protein (FMP) and whey protein concentrate (WPC)] were all investigated for their mechanical, physical, chemical, thermal and barrier properties. The properties of the resulting films were then compared with those of commercial wrap films [polyvinyl chloride (PVC)]. The film forming solution containing 7% (w/v) protein and 50% (w/w) glycerol was used to produce the films through a casting method. Of the protein‐based films, the GG film had the highest tensile strength and elongation, while the WPC film exhibited the lowest film solubility, water vapour permeability, light transmission in UV‐Vis range (200–800 nm) and film transparency. However, the colour of the FMP film and the thickness were closer to that of the PVC film, particularly the L* and b* values. The appearances of the protein‐based films were similar to the PVC film, and they were uniformly transparent. Therefore, biodegradable films produced from different types of protein sources exhibited differences in their properties. These results are consistent with data from FTIR and protein pattern analyses. Based on these findings, different sources of protein‐based films can be used as an alternative for food packaging applications. Copyright © 2015 John Wiley & Sons, Ltd.