Release of Nisin from Methylcellulose-Hydroxypropyl Methylcellulose Film Formed on Low-density Polyethylene Film

Abstract

Low-density polyethylene film was coated with a solution containing a high-molecular-weight or low-molecular-weight methylcellulose and hydroxypropyl methylcellulose. Films contained 10000, 7500, 5000, 2500, or 0 IU/cm 2 nisin. Film samples were placed into peptone water, and 10-L samples were removed and placed onto spiral plated lawns of Listeria monocytogenes. Zones of inhibition were measured using a caliper. Films containing 5000, 7500, and 10000 IU/cm 2 nisin inhibited L. monocytogenes after 30 min; films with 7500 and 10000 IU/cm 2 nisin inhibited L. monocytogenes after 60 min and 8 h, respectively. No zones of inhibition were observed after 24 h and 4 d for all films. After 8 d, zones of inhibition were observed for films with all levels of nisin except 2500 IU/cm 2 . Films with 0 and 2500 IU/ cm 2 nisin did not produce zones of inhibition throughout the study. Molecular weight of the cellulose-based carrier had no effect on inhibition of L. monocytogenes. A standard curve of inhibition was developed using solutions of 10000, 7500, 5000, 2500, or 0 IU/cm 2 nisin applied directly to lawns of L. monocytogenes. The amount of inhibition using a direct application of a solution was 25% to 50% more effective for inhibition of L. monocytogenes compared with the coated film samples. Overall, the coated film samples were effective for inhibition of L. monocytogenes, particularly when 7500 and 10000 IU/cm 2 nisin were used, but the release of nisin was not controlled and did not provide consistent inhibition throughout the 8-d study.

Lactic acid bacteria in an alginate film inhibit Listeria monocytogenes growth on smoked salmon

“…2); subsequent pathogen growth after 21 and 28 days indicates that the bacterium developed resistance to the action of nisin over time. This is in agreement with the study by Grower et al (2004), who reported that for maximum effectiveness of nisin films against L. monocytogenes, the nisin should be released and remain effective for the full time period, since any period without release may allow the pathogen to grow and become resistant. These authors used nisin concentrations up to 10,000 IU/g, the maximum level allowed by the FDA for foods.…”

Monitoring nisin desorption from a multi-layer polyethylene-based film coated with nisin loaded HPMC film and diffusion in agarose gel by an immunoassay (ELISA) method and a numerical modeling

“…The possibility of adherence of HPMC and PE films was obtained by PE film corona surface treatment at a potency of 5 kW before coating. Similarly, Grower, Cooksey, and Getty (2004) reported that nisin addition made no difference in the mechanical properties of LDPE films coated with a nisin-containing cellulose-based coating.…”

Engineering Properties of Polymeric-Based Antimicrobial Films for Food Packaging: A Review

“…The diffusion of potassium sorbate was studied by analyzing its concentration from the other chamber. In several studies involving commonly used synthetic films, the method of incorporation of the antimicrobial substance has been by coating the film with a solution containing the antimicrobial [7,19], while in others it has been possible to incorporate directly the substance in the film matrix [1,2,35]. This suggests that it is not always possible to incorporate the studied antimicrobial directly in the films' matrix.…”