Selective antimicrobial food packaging of composite poly(lactic acid) cobalt-citrate films

Abstract

Food spoilage is a well-known subject in worldwide research, involving a plethora of approaches linked to physical and chemical processes. Poised to develop active antimicrobial packaging materials addressing the specific issue, a composite film was prepared from biocompatible-biodegradable poly(lactic acid) (PLA), incorporating a bioinorganic hybrid metal-organic Co(II)-citrate (Co-cit) complex. The fabricated PLA-(Co-cit) film retained its physicochemical profile as attested to through FT-IR, UV-Visible, SEM, DSC, TGA, nanofocus-confocal microscopy, weight variation, moisture, bending, and mechanical tests, thus justifying further investigation in antimicrobial potency biological experiments. Testing involved Gram-positive/Gram-negative bacteria, revealing a well-defined antimicrobial profile, with clear specificity toward Listeria monocytogenes, thereby asserting proof of concept on the design of such materials. Collectively, the work sets the stage for development of materials conforming to demands of active packaging and employing physicochemically well-defined hybrid metal-organic species, bearing bacteria-specific antimicrobial properties, ultimately contributing to the maintenance of integrity and extension of shelf-life for foods.