ABSTRACT
The preserving potential of biopolymer coatings can be improved by adding natural antimicrobial and antioxidant compounds. The objective of this study was to evaluate the effect of natural coatings (gelatin (Gel), chitosan (Ch), and modified starch (MS)) incorporated with bitter orange peel extract (BOE) on the quality of the chicken fillets during cold. BOE had a high amount of phenolic compounds (145.28 mgGAE/g). Coating the fillets with pure BOE exerted a higher inhibitory effect against bacterial growth compared to composite coatings without extract. Lower microbial count (2-3 log CFU/g on days 9 and 12 of storage) was observed in the samples coated with composite biopolymers incorporated with BOE in comparison to the coatings without BOE. Composite coatings of Gel/MS/BOE showed lower FFA in the fillets followed by Gel/Ch/BOE and MS/Ch/BOE. The lowest TVB-N belonged to MS/Ch/BOE followed by Gel/Ch/BOE and Gel/MS/BOE which were 17.05, 17.39, and 19.40 mg/100 g at the end of the storage. Among the samples, pure BOE, Gel/MS/BOE, Gel/Ch/BOE, and MS/Ch/BOE showed the lowest peroxide value and the coatings containing chitosan had a slower rate of hydroperoxide generation. Drip loss showed a descending trend in all coated samples except for an enhancement in control and BOE-coated fillets, 6.42% and 6.39%, respectively, on day 12 of storage. Samples coated with Gel/MS and Gel/MS/BOE had the lowest drip loss during the storage period (5.96% and 5.98%, respectively). It should be noted that coatings containing chitosan had higher antimicrobial and antioxidant effects. The effect of the coatings as antimicrobial barriers and preservative agents were as follows: Gel/Ch/BOE > MS/Ch/BOE > Gel/MS/BOE. It can be concluded that the applied composite coatings in this work have a high potential to maintain and improve the quality of raw chicken fillets during storage in the refrigerator.
ABSTRACT
This study aimed at to formulate a food-grade nanoemulsion of tarragon essential oil (NEO) and investigate its antioxidant and antimicrobial properties. Oil in water NEO was formed by blending 10% of tarragon EO (TEO), 85% water, and a mixture of 5% surfactants, then antioxidant and antimicrobial activities were evaluated. The main components of TEO were estragole, beta-cis-ocimene, beta-trans-ocimene, and l-limonene. NEO droplet had a diameter of 50 nm and a zeta potential of - 30 mV. Results of free radical DPPH scavenging activity revealed that hydrogen donating capacity of the nanoemulsion was significantly higher than TEO and at 2.5 µg/mL concentration it showed complete inhibitory activity against DPPH. The ferric reducing potential was almost similar for TEO and NEO. NEO showed higher antibacterial potential against Staphylococcus aureus and Listeria monocytogenes and Shigella dysenteriae. The results of this work indicated that NEO had higher antioxidant and antimicrobial activity compared with free TEO.
ABSTRACT
Poultry meat is very susceptible to oxidation because of the high concentration of polyunsaturated fatty acids, which negatively affects the quality and nutritional values of chicken meat. Coccidiosis is the most common parasitic disease of poultry. Intending to limit anti-parasites usage in poultry feed and also because of the concerns about antibiotic resistance and residues in poultry products, there is a need for research to discover natural alternatives. The effect of nanocurcumin on antioxidant profile (carotenoid and vitamin E contents, lipid oxidation and antioxidant capacity) and pH of broiler chicken breast meat infected with Eimeria species was investigated. Fifty, one-day-old male Ross 308 broiler chickens were assigned to five treatments including non-infected and non-medicated control (NNC), infected non-supplemented control (INC), infected and medicated with nanocurcumin 300 mg kg-1 feed (NCRM1), infected and medicated with nanocurcumin 400 mg kg-1 feed (NCRM2) and infected and antibiotic medicated group. Infection with Eimeria acervulina, E. maxima, and E. tenella decreased vitamin E and carotenoid contents of chicken breast meat significantly. The NCRM2 had significantly enhanced carotenoid and vitamin E levels in chicken breast meat, so there was no significant difference between NCRM2 and NNC group. No significant change was observed in pH value among groups. Malondialdehyde value of breast meat was significantly lower in NCRM1 and NCRM2 than the INC group. The NCRM2 and NCRM1 showed the best antioxidant capacity even better than NNC. In conclusion, nanocurcumin could be a potential feed additive that can increase oxidant stability of broiler chicken breast meat.
