Development of a chicken feather protein film containing clove oil and its application in smoked salmon packaging

- Chicken feather protein (CFP) can be used as a film base material.
- CFP/gelatin composite film with good mechanical properties was prepared.
- The composite film containing clove oil displayed antimicrobial activity.
- The composite film can be used as an active packaging material for smoked salmon.

Chicken feathers, a by-product of the poultry industry, were utilized as a film base material after extraction of chicken feather protein (CFP). Composite films of CFP and gelatin were prepared, and their mechanical properties were investigated. The tensile strength and elongation at break of the CFP/gelatin composite film significantly (p < 0.05) increased as the gelatin content in the film increased. As a cross-linking agent, 0.5% cinnamaldehyde further improved the film's mechanical properties. Incorporation of clove oil into the composite film resulted in strong inhibition zones against Escherichia coli O157:H7 and Listeria monocytogenes compared with the film without clove oil. Packaging smoked salmon with the composite film containing 1.5% clove oil resulted in a decrease in the populations of E. coli O157:H7 and L. monocytogenes by 1.41 and 1.34 log CFU/g, respectively, compared with the control during storage at 4 °C for 12 days. Furthermore, the peroxide value and thiobarbituric acid reactive substances value decreased by 28 and 36%, respectively, in the smoked salmon packaged with the composite film containing 1.5% clove oil compared with the control during storage. These results suggest that a CFP/gelatin composite film with 1.5% clove oil can be used as an active packaging material for smoked salmon.