Corn Zein edible film containing Sumac fruit extract and encapsulated Thymus daenensis Celak essential oil to improving the shelf life of chicken fillet

The present study aims to develop an edible film based on corn Zein protein (Z) containing sumac fruit extract (SFE) and Thymus daenensis Celak essential oil (TEO) encapsulated with beta-cyclodextrin and its effect on the shelf life of chicken fillets stored in refrigerator conditions. The results of FTIR showed that Z films containing SFE, free and encapsulated TEO formed effective chemical bonds in the strength of the films. According to the results, adding SFE and TEO led to an increase in the tensile strength (1.65 and 1.59 MPa) and elongation at the break (55.08 and 46.47%) of the films, and in the samples containing both substances, these parameters (0.46 MPa and 1.99%) were significantly (p ≤ 0.05) reduced. Upon adding SFE and TEO, the moisture level of the films (0.45 and 0.74%) decreased significantly (p ≤ 0.05). In all samples, over time, the microbial population (aerobic mesophilic bacteria, Psychrotrophic bacteria, lactic acid bacteria, and Enterobacteriaceae), pH, thiobarbituric acid reactive substances, and total volatile basic nitrogen (TVB-N) values increased; but these trends were significantly (p ≤ 0.05) lower in the all wrapped samples compared to the unwrapped group. Also, the sensory analysis of the treatments showed that the films containing SFE and encapsulated TEO (odor (score of 3.55), color (score of 3.85), and overall acceptability (score of 3.70)) accounted for the highest efficiency in preventing changes in the studied fillets until the end of the storage period. In general, it can be concluded that the edible corn Zein film containing encapsulated TEO and SFE can improve the quality and prolong the shelf life of the wrapped chicken fillets and can be applied as a good alternative to plastic packaging in future.