CHITOSAN- AND PECTIN-BASED COATINGS WITH INCORPORATED ACTIVE COMPONENTS FOR APPLICATION IN ACTIVE FOOD PACKAGING

Abstract

The subject of this research was the development of biodegradable and eco-friendly material based on natural biopolymers from renewable sources, with the addition of active components for application in active food packaging. The main principle was the incorporation of the active components (lemongrass (Cymbopogon citratus L.) essential oil, ZnO nanoparticles, or Zn(CH3COO)2∙2H2O) with antimicrobial activity in the polymer matrix (chitosan, pectin, and gelatin), and their slow release during the time. All of the used components are listed as GRAS (Generally Recognized as Safe) by the U.S. Food and Drug Administration. Different formulations of emulsions and dispersions were processed for mutual comparison. The stability of chitosan and pectin emulsions was determined by using laser diffraction methods. Chitosan emulsions exhibited higher stability during 30 days of storage. The chitosan emulsions and dispersions exhibited a higher antibacterial effect in vitro against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. Biopolymer coatings were formed by the spraying of emulsions on existing packaging. The effects of biopolymer coatings on the development of microorganisms on fresh raspberries (Rubus idaeus L.) were performed in vivo during eight days of raspberry storage at refrigerator temperature. The tested coatings extended the shelf life of stored raspberries from four to eight days. The synergistic effect between lemongrass essential oil and ZnO nanoparticles or Zn(CH3COO)2∙2H2O was observed both in vivo and in vitro.