Effect of chitosan-gelatin coating containing nano-encapsulated tarragon essential oil on the preservation of pork slices

There is an increasing demand for bio-based packaging materials incorporated with active nanoparticles as one of the new technologies to obtain food products with improved quality and extended shelf-life. The objectives of this study were to develop a chitosan-gelatin based edible coating incorporated with nano-encapsulated tarragon essential oils (TEO) and to investigate the effects of chitosan-gelatin coatings containing TEO or TEO-loaded nanoparticles (TEO-NPs) on the preservation of pork slices during refrigerated storage for 16 days. Nanoparticles with the average diameters of 246.27-504.60 nm were produced using different mass ratios of chitosan to TEO (1:0, 1:0.2, 1:0.4, 1:0.6, 1:0.8 and 1:1) by ionic gelation method. Zeta potential and encapsulation efficiency (EE) of the prepared TEO-NPs were 27.07-37.12 mV and 9.83-35.57%, respectively. TEO-NPs with the maximum EE were applied for preparing the edible coatings. The results suggested that the coating treatments could significantly inhibit quality deterioration of pork slices. Nano-encapsulation contributed to the sustained release of TEO and caused an improved antioxidant, antibacterial and sensory properties. The study suggests that chitosangelatin coating incorporated with TEO-NPs could be developed as a prospective active packaging to preserve pork slices.