Enhancement of konjac glucomannan/carrageenan blend films by incorporating cellulose nanocrystals/tannic acid stabilized Litsea cubeba essential oil Pickering emulsion and their application to pork preservation

With increasing demands for environmental protection and food safety, biodegradable active food packaging is gaining attention. Hereby, konjac glucomannan/carrageenan blend films (KCNTO) incorporating Litsea cubeba essential oil (LCEO) Pickering emulsion stabilized by cellulose nanocrystals/tannic acid were developed and evaluated for their preservation effect on pork. The formation, structure, physical properties, antioxidant and antimicrobial activities of KCNTO, as well as the release of LCEO were investigated. The results showed that the viscosity and pseudoplasticity of KCNTO film-forming solutions decreased due to LCEO Pickering emulsion interfering with the molecular entanglement network of konjac glucomannan/carrageenan. LCEO droplets were homogeneously distributed in KCNTO to make its structure loose. Hydrogen bonding interactions occurred between LCEO Pickering emulsion and the film matrix. The addition of LCEO Pickering emulsion improved KCNTO's elongation at break, water contact angle, water vapor barrier and UV shielding, while giving it excellent antioxidant and antimicrobial activities. LCEO was slowly and sustainably released from KCNTO at 25 degrees C in air. KCNTO-8 maintained the quality of pork by slowing down the increase in pH, aerobic plate count and thiobarbituric acid reactive substances during storage at 4 degrees C. The findings suggested that KCNTO was a promising active packaging material for pork preservation.