Development of Antifungal Polyethylene Films by Coating Spray Drug

GRAFIA, ANA LUISA; BARBOSA, SILVIA ELENA

Sitges

Conferencia; Third International Symposium: Frontiers in Polymer Science; 2013

Editorial Elsevier

Packages with antimicrobial activity based on preservative releasing provide a promising form of active packaging systems applicable in food processing. In this sense the development of low costs plastic films with this kind of specific activity is the key. The polyethylene (PE) is the most used polyolefin in packaging industry because their good cost/performance relationship. Also, natamycin (also known as pimaricin) a commercially important polyene antifungal compound is one of the few antibiotics which are still recommended by FDA as food additive and classified as a GRAS (generally regarded as safe) compound. This strong antifungal agent is slightly soluble in water and inhibits the growth of both yeasts and molds. In this work, antifungal PE films are developed by spraying natamicyn directly on commercial polyethylene during film production by cast extrusion. In order to obtain the spray coating experimental conditions, heptane was used as spray solvent with different drug concentration. The coating homogeneity and particle tethering were assessed by optical and scanning electron microscopy and corroborate by using of Fourier Transform Infrared Spectroscopy-Attenuated Total Reflectance. Special experiment by comparing the film surfaces with and without strong drug extraction were performed. The results shows that sub-micron particles are homogeneously, well dispersed and strongly attached at the PE surface. On the other hand, films conserved its mechanical properties. The antifungal activity of natamicyn coated films were tested against Aspergillus niger with agar disc diffusion assay. Different coating concentrations were studied and compared with no coating PE. All coated films were very effective in inhibiting microorganisms growth, evidencing that natamicyn remains so active after coating process. In the opposite, PE does not show any inhibitory antifungal activity alone. The present process seems to be a promissory way to obtain low costs antifungal package films.