Franziska Trodtfeld (Jena, DE), Dr. Tina Tölke (Jena, DE), PD Dr. Cornelia Wiegand (Jena, DE)
Abstract text (incl. figure legends and references)
The food packaging industry is trying to improve packaging durability and strength for product shelf life. To reduce packaging waste, biodegradable polymers are being used more frequently. However, organic packaging materials have less effective barrier properties than existing materials. Another approach to increase shelf life is to incorporate active ingredients with antimicrobial activity. Silica added to biodegradable polymers improves their water resistance and mechanical and thermal properties and extends their shelf life. Organic acids have antimicrobial activity due to pH changes and antioxidative activity. The goal is to incorporate them into the matrix with targeted release. An organic-inorganic hybrid gel was developed using a polymer matrix (polypeptides, monosaccharides). The organic compounds were crosslinked with nanometer aggregates of Si-precursor, which were hydrolyzed and condensed in the organic solution. Additional silica particles were loaded with fumaric acid and encapsuled with a layer-by-layer system, the encapsuled particles were dispersed into the finished solutions and coated onto the surfaces of matrix materials. The hybrid gel coating has excellent oxygen barrier properties, but its effectiveness decreases as the relative humidity in the pressure chamber increases. The gel"s network structure was analyzed using IR technology and rheology tests on the solutions. Encapsulation of particles ensures their dispersion in the coating solution without premature release of the active ingredient. These particles exhibit strong antimicrobial activity against E. coli and S. aureus. Biocompatibility was assessed through specific bioassays. This synthesized hybrid gel has excellent oxygen barrier and antimicrobial properties but requires a protective layer against water vapor permeability to be stable in higher humidity environments. The results of biocompatibility testing suggest that these materials are safe for human contact.