Migration, physical and antibacterial properties of silver zeolite/poly(butylene succinate) composite films for food packaging applications

Abstract

Bacterial growth on food is a main factor in the reduction of food quality, leading to short-term food shelf life. Development of antibacterial packaging can inhibit the bacterial growth and extend food shelf life. Silver loaded zeolite was used as the antibacterial agent in this work. Three zeolites (different Si/Al ratio) such as zeolite A, zeolite Y, and zeolite Socony Mobil-5 (ZSM-5) incorporating with the same silver content were prepared. The characterization was carried out by energy dispersive X-ray spectroscopy, scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, nitrogen adsorption, and color analysis. Antibacterial activity of the three silver zeolites was tested against Escherichia coli and Staphylococcus aureus. Silver loaded zeolite ZSM-5 showed better bacterial inhibition than silver incorporated zeolite A and Y. For composite film preparation, silver loaded zeolite ZSM-5/poly(butylene succinate) composite films were prepared by varying silver loaded zeolite ZSM-5 concentrations and characterized by different techniques (mechanical test, scanning electron microscopy, and color analysis). Poly(butylene succinate) composite films filled with silver loaded zeolite ZSM-5 showed 99.9% of bacterial reduction within 24 h, indicating the effective antibacterial activity. From the silver migration results, the silver release from poly(butylene succinate) films was less than the limitation of European Food Safety Authority regulation, indicating the safety for food packaging applications.