Antimicrobial defenses of table eggs: Importance of antibacterial proteins in egg white as a function of hen age in an extended production cycle.
Food Microbiol
; 107: 104068, 2022 Oct.
Article
em En
| MEDLINE
| ID: mdl-35953175
ABSTRACT
The importance of egg natural defences to prevent bacterial contamination and their relation with hen age in extended production cycles were evaluated. Egg-white from eggs of different hen age groups (up 100-weeks-old) and lines (Hy-Line white and brown) were inoculated with Gram-positive Staphylococcus aureus or Gram-negative Salmonella Typhimurium, ranging from 103-106 CFU/mL. Our results show that concentrations of egg-white lysozyme and, particularly, ovotransferrin are important to modulate bacterial survival in a dose-dependent matter. Depending on protein concentration, their effect ranges from bactericidal to bacteriostatic, with a threshold for bacterial contamination that depends also on hen age and line. The concentrations of lysozyme and ovotransferrin increased with hen age (up to 2 and 22 w/w% of total protein, respectively), and eggs laid by older hens exhibited the greatest potential to prevent the growth of the highest Salmonella inoculum (106 CFU/mL). Salmonella-penetration experiments demonstrated that non-contaminated eggs display significantly higher concentrations of antimicrobial proteins. However, eggs from older hens needed a higher concentration of these proteins (>20% ovotransferrin) to prevent bacterial contamination, showing that antimicrobial protein concentrations in egg-whites was not the only factor influencing bacterial contamination. Finally, this study demonstrated that egg-white of eggs produced by old hens are less prone to contamination by Salmonella.
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Base de dados:
MEDLINE
Assunto principal:
Galinhas
/
Clara de Ovo
Limite:
Animals
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article