Prediction of the coating requirements for smoked salmon protection against Listeria monocytogenes using a defatted mustard meal-based antimicrobial edible film containing thiocyanates

- A method for predicting antimicrobial coating requirements was developed.
- Listeria monocytogenes-safe-storage time for a coated food can be predicted.
- Plasticizer and temperature effects on antimicrobial diffusion are presented.

The antimicrobial film-coating requirements for obtaining protection against Listeria monocytogenes in smoked salmon using a defatted mustard meal-based antimicrobial edible film (DMM film) were predicted by fitting a mathematical model to the experimental data. The concentration of thiocyanate ion (SCN−) (0.28 ± 0.02 mg/g) inhibiting L. monocytogenes (4.0 ± 0.2 log CFU/g) as well as diffusion and partition coefficients of SCN− in smoked salmon coated with the film were experimentally determined for prediction. The diffusion coefficients for the SCN− diffusion in the film and in the salmon at 4 °C and the partition coefficient were 2.7 × 10−14 m2/s, 1.9 × 10−10 m2/s, and 0.8, respectively. The film containing an SCN− at 0.41 mg/g was predicted to provide 19.7 h of protection in smoked salmon against continuous-post-contamination by L. monocytogenes at 4.0 log CFU/g during which SCN− remains above the inhibitory concentration of 0.28 mg/g. For 24 h inhibition, the necessary initial concentration of SCN− was estimated as 0.43 mg/g in a 0.14 mm thick film. The methods developed in this study allow for the prediction of antimicrobial DMM film requirements in the protection of smoked salmon against L. monocytogenes.