Chitosan-keratin biodegradable plastic films for the control of Listeria monocytogenes in bovine meat

ORJUELA PALACIO, JULIANA MARCELA; PEREZ-CALDERON JOHN; GIMENEZ, BELEN; ZARITZKY, NOEMÍ ELISABET

Buenos Aires

Congreso; World Congresses of Chemical Engineering (WCCEs); 2023

World Chemical Engineering Council (WCEC)

Development biomaterials for pathogen control is an opportunity for the reconversion of biomass generated by industrial sectors. Biodegradable composite films with antimicrobial properties against Listeria monocytogenes were obtained and used as separetors in beef. The matrices were formulated by blending chitosan (Ch) a cationic aminopolysaccharide biopolymer with antimicrobial activity; and keratin (K) a protein with disulfide bonds, biocompatible, biodegradable and the main component of the biomass of the poultry industry. Lyophilized keratin (Kp), extracted from hydrolyzed feathers (NaOH= 5 %w/v), was incorporated into a Ch (2 %w/v) solution. The films F(Ch-Kp) (ratio of 70:30 w:w) were cast-dried for 24 hours at 35°C, then thermally cured at 120°C, 30 minutes. The addition of Kp generated a more stable matrix in aqueous media with high thermal stability (DSC, TGA). F(Ch/Kp) showed a hydrophobic tendency (WVP= 4.7x10-11 g/s.m.Pa, contact angle= 97.1°). FTIR-ATR analysis showed the predominance of Ch signals and decrease in Amide-I and II due to the interaction of biopolymers. Antimicrobial activity on L. monocytogenes was evaluated. In the first stage, the effectiveness of F(Ch/Kp) for pathogen inhibition was demonstrated using the disk diffusion method on the L261 strain (108 CFU/mL), with a 30% inhibition rate. In the second stage, films were used as separators in beef inoculated with L261 (105 CFU/mL) stored 7 days at 4°C. Counts of L. monocytogenes showed a retardation in the growth. F(Ch/Kp) provides a means of controlling the development of L. monocytogenes in beef, while also offering an alternative for the valorization of biomass.