Chitosan coatings incorporated with free or nano-encapsulated Paulownia Tomentosa essential oil to improve shelf-life of ready-to-cook pork chops

The aims of this study were to prepare a natural active chitosan coating loaded with nano-encapsulated Paulownia Tomentosa essential oils (PTEO) and to investigate the effects of the coating treatments on lipid oxidation, microbial growth, and sensory attributes of ready-to-cook (RTC) pork chops over a 16-day storage at 4 degrees C. PTEO-incorporated chitosan nanoparticles (PTEO-CNPs) with the mean diameter of 185 nm were prepared by the ionic gelation method. Zeta potential, encapsulation efficiency (EE) and polydispersity index of nano-particles were 41.3 mV, 40.6% and 0.67, respectively. The results of coating of RTC pork chops indicated that all coating treatments could effectively decrease the microbial growth and chemical spoilage of samples compared to the control (p < 0.05) during the storage. Encapsulation contributed to the sustained release of PTEO and resulted in an enhanced antimicrobial, antioxidant activity and sensory attributes. The study suggests that nano-encapsulated PTEO-based edible chitosan coating can be a prospective active packaging for prolonging the shelf-life of RTC pork chops.