Formulation of an antimicrobial coating containing Nisaplin® intended for large scale production and inhibition of spoilage microorganisms

摘要

Antimicrobial food packaging could reduce food waste by extending shelf-life in addition to preserving food quality and safety. Utilization of the antimicrobial peptide Nisaplin®, which is an FDA GRAS approved additive, has the potential to be used in commercial antimicrobial food packaging applications. The objective of this study was to produce a Nisaplin containing coating formulated for large scale production equipment while maintaining efficacy. Differential scanning calorimetry (DSC) testing was conducted in order to determine a grade of polyvinyl alcohol (PVOH) and compatible plasticizer. Compatible plasticizers were determined based upon the plasticizers ability to lower the T_m (melt temperature) of the PVOH. Drawdowns were also produced from trial formulations to measure specific liquid coating characteristics and make observations of dried coated films. Percent solids (%) of liquid coatings and pH testing in additional to general observations were conducted. General observations of color, adhesion of the coating and seal testing were conducted on dry coated films. Film on lawn testing was conducted on dry coated films against Micrococcus luteus and Listeria monocytogenes. Control films did not contain Nisaplin. DSC testing revealed that glycerin lowered the melt temperature of partially hydrolyzed PVOH from 189.66°C (373.39°F) to 150.94°C (303.69°F) making the coating more suitable for sealing and less brittle. The pH was found to be between 4.0 and 4.5 for coatings containing Nisaplin (T) and 4.5-5.0 for control coatings (C) which did not contain Nisaplin. Average percent solids were 22.82% (T) and 20.63% (C). Coated films also achieved inhibition against M. luteus and L. monocytogenes compared to the control. The coated film was effective against a spoilage indicator organism in addition to a foodborne pathogen. Based on the characteristics of the coating and efficacy, it is possible to produce a commercial grade antimicrobial product containing Nisaplin that can extend the shelf-life of RTE food products.