Chicken meat, due to its high percentage of proteins and nutrients, as well as its affordable price compared to other animal proteins, has attracted the attention of many consumers. Therefore, the use of cost-effective methods to extend the shelf life of chicken meat during refrigeration and freezing is of great importance. Deep eutectic solvents are a new category of green solvents,with unique properties, including antimicrobial and antioxidant features, can be used in edible coatings and films to extend shelf life. The present study aimed to preserve the quality of chicken meat during storage at 6 °C and -18 °C using coatings with nanoemulsions produced from deep eutectic solvents. To prepare the deep eutectic solvents, the mixtures of menthol:decanoic acid (1:2), menthol:acetic acid (2:1), and menthol:lactic acid (2:1) were incubated at 42 °C for 1 h to form the deep eutectic solvents, and the physicochemical properties of them were eva‎luated. Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC) were used to study the change in functional groups and thermal properties of the solvents, respectively. FTIR and DSC results confirmed the formation of the deep eutectic solvents, with their melting points reduced below 6°C. Additionally, all three solvents had significantly different viscosity (P<0.01). Then, nanoemulsions were produced from the obtained deep eutectic solvents. The physicochemical properties of the produced nanoemulsions, including pH, color, turbidity, hydrodynamic diameter, and antioxidant and antimicrobial activities, were eva‎luated. The produced nanoemulsions had acidic pH, with the highest pH belonging to the menthol-decanoic acid eutectic nanoemulsion. The menthol-lactic acid and menthol-acetic acid nanoemulsions had particle sizes ≤ 10 nm and the minimum turbidity. The highest antioxidant activity was observed in the decanoic acid containing nanoemulsion, while the highest antimicrobial activity was observed in the acetic acid containing nanoemulsion. Finally, the chicken fillets were dipped in nanoemulsions to be coated and then were packedat polyethylebne bags. The pH, drip loss, cooking loss, oxidation level, microbial growth, color, and texture of the samples were eva‎luated over 7 days of storage at 6 °C and 4 months at -18°C. The results showed that coated chicken meat with deep eutectic solvent nanoemulsions effectively prevented pH increment and microbial spoilage in the chicken meat. In samples stored at both 6 °C and -18 °C, drip loss significantly increased during storage (P<0.05). Also, water holding capacity decreased in coated samples. Oxidation levels in all samples coated with nanoemulsions containing deep eutectic solvents were lower than in the control one at both storage temperatures. The highest lightness at both storage temperatures was observed in samples coated with the acetic acid containing nanoemulsion. Additionally, texture firmness in all coated samples was higher than in the control one during storage at 6°C; however the highest texture firmness was observed in samples coated with nanoemulsions containing acetic and lactic acids during storage at -18°C. Overall, the results indicated that after the storage period, coated chicken fillets maintained desirable properties, while control samples lost their suitable characteristics after 5 days (at 6°C) and 1 month (at -18°C). This study demonstrated that coating with nanoemulsions containing acetic and lactic acids can significantly inhibit the growth of microorganisms, thereby providing chicken meat with suitable microbial and chemical quality for consumers.

نفيسه سلطاني زاده

مريم فنائي كهراني

اميرحسين گلي , اميرحسين مهدوي