Physical, mechanical and antimicrobial properties of Argentine anchovy (Engraulis anchoita) protein films incorporated with organic acids

Physical, mechanical and antimicrobial properties of protein films from Argentine anchovy (Engraulis anchoita) incorporated with 0, 0.50, 0.75 and 1.50% sorbic or benzoic acids were investigated against Escherichia coli O157:H7, Listeria monocytogenes, Salmonella Enteritidis and Staphylococcus aureus. The effects of films containing 1.50% sorbic or benzoic acids were tested on meat inoculated with Escherichia coli O157:H7 and Listeria monocytogenes during storage at 5 °C. The increased concentration from 0.50 to 1.50% of sorbic and benzoic acids resulted in decreased tensile strength and increased elongation at break, color difference, opacity, water vapor permeability and solubility. Scanning electron microscopic images of the control film revealed a homogeneous and continuous structure and the presence of micropores on the film surface containing 1.50% of sorbic or benzoic acids, which contributed to the physical and mechanical properties of the resulting films. The control films did not inhibit many microorganisms tested in this study. Films with 1.50% sorbic or benzoic acids had the highest inhibition against Escherichia coli O157:H7, Salmonella Enteritidis and Listeria monocytogenes, however they did not inhibit Staphylococcus aureus. Films with 1.50% sorbic or benzoic acids applied in meat showed the greatest inhibition of Listeria monocytogenes and Escherichia coli O157:H7. These results suggest that the films containing antimicrobials can be used to promote safety and quality of packaged meat, though the physical and mechanical properties of the films could be modified.