RHEOLOGICAL MODEL FOR THE MECHANICAL-PROPERTIES OF MYOFIBRILLAR PROTEIN-BASED FILMS

A phenomenological rheological model was developed to describe the mol ecular interactions and predict the mechanical properties of fish myof ibrillar protein-based films, irrespective of their thickness. The mod el was built of a parallel array of Maxwell and elastic elements in wh ich a fracture element was introduced. The total number of parallel br anches was directly correlated with the most characteristic dimension of the samples, i.e., the film thickness. The rheological parameters ( alpha, elastic modulus, and viscosity coefficient) were determined fro m numerous experimental data sets and appeared to be independent of th ickness. They could be used to characterize the molecular interactions in the films. These parameters were only sensitive to the type of dat a used for calculations (force-deformation, relaxation, or creep) and to the range of experimental conditions applied to obtain these data. The model successfully predicted force-deformation-time relationships for these biopolymer-based films.