title: Effect of temperature and time of storage on protein stability and anti-salmonella activity of egg white.
abstract: Hen egg white contains numerous molecules of interest for human health, including antimicrobial proteins. Little information is available concerning changes in the antimicrobial activity of egg white during storage; therefore, we analyzed the potential of egg white to inhibit growth of Salmonella enterica serovar Enteritidis following storage at 4, 20, or 37°C for 30 days prior to inoculation. Egg white displayed higher anti-Salmonella activity after a few days of storage at 20 and 37°C. The rate of increase in activity was more rapid and pronounced at the higher temperature. However, egg white stored at 20°C retained higher antimicrobial activity than that of egg white stored at 4 or 37°C, when the entire storage period is taken in consideration. In contrast, storage of egg at 37°C for more than 14 days reduced the bacteriostatic potential of egg white. Statistical analyses revealed a correlation between pH and the antimicrobial activity of egg white. Moreover, diminished antimicrobial activity was associated with degradation of ovalbumin and ovotransferrin, as assessed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and mass spectrometry. However, the fluctuation in anti-Salmonella activity of egg white could not be related to any variation of trypsin-like, chymotrypsin-like, or gelatinolytic activities that potentially account for degradation of antimicrobial egg white proteins.
authors.affiliation: INRA, UR83 Recherches Avicoles, Fonction et Régulation des Protéines de l'Oeuf, Nouzilly, France. srehault@tours.inra.fr
authors.forename: Sophie
authors.initials: S
authors.lastname: Rehault-Godbert
authors.forename: Florence
authors.initials: F
authors.lastname: Baron
authors.forename: Sandrine
authors.initials: S
authors.lastname: Mignon-Grasteau
authors.forename: Valerie
authors.initials: V
authors.lastname: Labas
authors.forename: Michel
authors.initials: M
authors.lastname: Gautier
authors.forename: Maxwell T
authors.initials: MT
authors.lastname: Hincke
authors.forename: Yves
authors.initials: Y
authors.lastname: Nys
mesh_terms: D000818:Animals; D003257:Consumer Product Safety; D004527:Egg Proteins / Q000032:analysis*; D004529:Egg White / Q000737:chemistry* / Q000382:microbiology*; D005506:Food Contamination / Q000032:analysis; D005511:Food Handling / Q000379:methods; D005516:Food Microbiology; D005519:Food Preservation / Q000379:methods*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D055550:Protein Stability; D012477:Salmonella enteritidis / Q000254:growth & development*; D013696:Temperature; D013997:Time Factors
chemical_list: D004527:Egg Proteins