Preparation and characterization of edible films from fish water-soluble proteins

As a means of effective utilization of fish water-soluble proteins (FWSP), which are mostly discarded into the waste water of seafood processing plants, the development and characterization of edible films from FWSP of blue marlin meat were investigated. The film-forming solutions were prepared from 3% FWSP solutions at pH 10 with 1.5% glycerol as a plasticizer, followed by heating at 70 degrees C for 15 min. Edible films were successfully prepared by drying the film-forming solutions at 25 degrees C for 20 h. It was revealed that FWSP had to be denatured somehow to unfold the protein structure, and the interaction of FWSP molecules, particularly through disulfide linkages, was attributed to the formation of films. Transparent edible films thus formed had better flexibility and lower water vapor permeability compared with most of the other protein films.