Influence of heating, protein and glycerol concentrations of film-forming solution on the film properties of Argentine anchovy (Engraulis anchoita) protein isolate Original Research Article

This study was conducted to evaluate the influence of thermal treatment (74, 82, and 90 °C), glycerol (30%, 35%, and 40%, w/w) and protein concentrations (3.0%, 3.5%, and 4.0% w/w) of film-forming solution on the properties of Argentine anchovy (Engraulis anchoita) protein isolate (API) films produced by casting. The API presented 88.8% of proteins, 5.5% moisture, 1.3% lipids, 1.0% ash and 53.3% of polar amino acids. The DSC of protein isolate was observed at maximum temperature of 62.2 °C and ΔH 6.4 J/g. The thickness, water vapor permeability, color difference and opacity of the films were not affected by the experimental variables studied (p > 0.05). The lowest solubility, elongation, and highest tensile strength of the films occurred at low temperature, low protein and glycerol concentrations (p < 0.05). Micrographs obtained by scanning electron microscopy of the films showed homogeneous surfaces at low temperature.