Potential of pectin-chitosan based composite films embedded with quercetin-loaded nanofillers to control meat associated spoilage bacteria

Abstract

Increasing consumer demands for healthy, minimally processed, contamination-free food with extended shelf life have exerted pressure on the food industry to search for more effective and biodegradable packaging materials against spoilage agents. Pectin-chitosan based nanocomposite films were developed and evaluated for the impacts of antimicrobial-loaded nanofillers [(quercetin-loaded nano-liposomes (QNLs)] on the physico-mechanical, thermal, and antibacterial properties against meat-associated spoilage pathogens. QNLs were observed with an average size of 191 ± 7 nm by dynamic light scattering with a negative zeta-potential value of −37 ± 5.7 mV. Scanning electron microscopy revealed round and smooth surface morphology of QNLs. FTIR spectroscopic analyses confirmed the encapsulation of quercetin in liposomes via weak electrostatic or hydrophobic interactions. The addition of nanofillers in composite films increased the tensile strength (9.74 ± 0.26 MPa) and Young's modulus (24.17 ± 0.64 MPa) of the nano-active films as compared to active films (2.49 ± 0.02 MPa and 5.04 ± 0.04 MPa), respectively. Similarly, opacity (3.10 ± 0.04) and moisture content (31.03% ± 1.81%) values of nano-active films were lesser as compared to non-active films (5.35% ± 0.07% and 84.24% ± 0.45% respectively) owing to the hydrophobic nature of QNLs. Thermal analyses performed by TGA and DSC confirmed the thermal stability of nano-active films. Nano-active films exhibited excellent antimicrobial potential (spot-on-lawn and quantitative food application assays) against multidrug-resistant meat pathogens including Escherichia coli, Listeria monocytogenes and Salmonella enterica. Hence, pectin-chitosan based nano-active films have promising applications for the preservation of meat products from spoilage bacteria.