A Novel Strategy for Reducing Salmonella Enteritidis Cross-Contamination in Ground Chicken Meat Using Thymol Nanoemulsion Incorporated in Chitosan Coatings

• Published in: Food and bioprocess technology 2024-09, Vol.17 (9), p.2706-2717
• Main Authors: da Silva, Bruno Dutra, Lelis, Carini Aparecida, do Rosário, Denes Kaic Alves, da Silva Mutz, Yhan, da Silva, Carolina Ramos, Conte-Junior, Carlos Adam
• Format: Article
• Language: English
• Subjects: Agriculture; Bacteria; Bacteriostats; Biotechnology; Chemistry; Chemistry and Materials Science; Chemistry/Food Science; Chickens; Chitosan; Coating effects; Coatings; Contamination; Emulsions; Fillets; Food contamination; Food safety; Food Science; Meat; Minimum inhibitory concentration; Nanoemulsions; Poultry; Product safety; Salmonella; Salmonella Enteritidis; Soil contamination; Thymol
• ISSN: 1935-5130; 1935-5149
• DOI: 10.1007/s11947-023-03283-y

This study evaluated the capability of a thymol nanoemulsion ( n THY) to reduce cross-contamination with Salmonella Enteritidis in ground chicken meat. First, an n THY (~ 54 nm) was prepared in a high-shear speed system (rotor–stator) and proved stable, remaining below 100 nm for 30 days in storage at 4 °C. Then, a minimum inhibitory concentration assay was performed by combining S . Enteritidis with viable native bacteria from chicken meat. n THY presented half the MIC that was observed for its non-nanoemulsified versions for Salmonella Enteritidis (MIC = 0.31 mg/mL) and combined with native chicken bacteria (MIC = 0.625 mg/mL). A chitosan (CH) coating containing n THY (6 mg/mL), equivalent to 10 × MIC ( S. Enteritidis + native chicken bacteria), was prepared for in situ evaluation. Two groups of distinct chicken fillets were prepared for cross-contamination during grinding: chicken fillets experimentally contaminated with S . Enteritidis (~ 6.5 log CFU/g) and chicken fillets without S . Enteritidis but with the applied treatments (control, coated with CH, n THY, and CH +  n THY). n THY showed a bacteriostatic effect throughout the 7 days of storage. The CH +  n THY coating was the best treatment applied, reducing cross-contamination by up to 1.91 log CFU/g compared to uncoated samples. Thymol nanoemulsions can be natural alternatives to guarantee the microbiological safety of meat and meat products.