Antioxidant and antimicrobial effects of Zataria multiflora Boiss. and Cuminum cyminum L. alcoholic extracts in bioactive coatings on chicken meat shelf life

The environmental hazards of polymer packaging have increased the tendency to use the biodegradable composites. Due to the use limitations of synthetic antioxidants and antibiotics, the use of alternative natural products has been developed. In this study, the antioxidant and antimicrobial effects of Zataria multiflora Boiss. and Cuminum cyminum L. alcoholic extracts in the bioactive coatings on the shelf life of chicken meat were evaluated and compared with propyl gallate. For this purpose, an experiment was conducted in a completely randomized design with five experimental treatments including the uncoated chicken fillets (control), fillets coated with 8% sodium caseinate, sodium caseinate-based coated enriched with thyme extract (1.5%), cumin extract (1.5%), and propyl gallate (100 ppm) and three replications for 10 days at refrigerator temperature. The results showed that the use of sodium caseinate coating reduced the number of aerobic mesophilic bacteria, psychrophilic bacteria, thiobarbituric acid index, peroxide value, and total volatile nitrogen compounds of the fillets during storage. The use of plant extracts and propyl gallate increased the antioxidant and antimicrobial efficiency of the bioactive coatings. At the end of storage period, the fillets coated with sodium caseinate- cumin extract showed the lowest amount of aerobic mesophilic and psychrophilic bacteria and the total volatile nitrogen compounds (p <0.05) and the fillets coated with sodium caseinate- thyme extract showed the lowest thiobarbituric acid index and peroxide value (p <0.05) with no statistically significant difference with the bioactive coatings containing propyl gallate. Therefore, the bioactive coating of sodium caseinate containing cumin and thyme extracts can be used to increase the shelf life of chicken fillets at the refrigerator storage for at least 10 days.