Development and Characterization of Pectin-Based Antimicrobial Packaging Films Containing Nanoemulsified Trans-Cinnamaldehyde

In this study, an antimicrobial plant-based film was developed using pectin which is incorporated by different percentages of nanoemulsified trans-cinnamaldehyde (TC). The nanoemulsion of TC was incorporated into pectin to form films containing TC at concentrations of 5.00%, 3.33%, 2.50% and 2.00% (w/w). The nanoemulsion of TC was formed by using soybean lecithin as an emulsifier and had a zeta potential of −57 mV and an average size of 106 nm. The analysis showed that the addition of emulsified TC enhanced the light barrier properties, but the opacity of films increased due to the increase in light absorption, coalescence, and light-scattering phenomena. Films containing the nanoemulsion of TC exhibited reduced tensile strength and elasticity due to structural discontinuities in the film network caused by the presence of the nanoemulsion of TC, while elongation at break increased for TC concentrations of 2.50% and 2.00%. The films retained their infrared spectra, but their thermal stability decreased slightly. The incorporation of TC nanoemulsion significantly reduced the glass transition temperature, as shown by the differential scanning calorimetry analysis. The active films showed antimicrobial activity against Listeria innocua and Escherichia coli, indicating their potential for various food applications.