Effect of convection drying and lyophilization of fish myofibrillar proteins on the technological properties of biodegradable films.

This study aimed to verify the effects of different drying methods and temperatures of fish myofibrillar proteins (MPs), on the technological properties of biodegradable films. The MPs were dried by lyophilization at −60 °C for 48 h and by convective drying of hot air at 40 °C, 60 °C, and 80 °C. In the drying by convection, drying curves were constructed and the adjustments of mathematical models were evaluated. The films were formulated with 1.5% proteins (w/v) and 30% glycerol (w/w), and they were characterized. The drying times found were 540 min (40 °C), 300 min (60 °C), and 120 min (80 °C). The "Logarithmic" models followed by the "Diffusion approach" were the ones that best fit for all temperatures. The results of protein electrophoresis and the characterization of the film showed that the convective drying caused changes in the three-dimensional structure of the proteins, favoring the formation of a highly cross-linked protein network with numerous hydrogen bonds, hydrophobic interactions, and disulfide bonds, and generating films with properties equal to or better than lyophilized proteins. [ABSTRACT FROM AUTHOR]