title: Effect of ultrasonic treatment on reduction of Esherichia coli ATCC 25922 and egg quality parameters in experimentally contaminated hens' shell eggs.
abstract: BACKGROUND
  In this study, hen eggs which were experimentally contaminated with Esherichia coli ATCC 25922 were used. Contaminated eggs were washed statically (S5 to S30; 0 kHz) and by ultrasonic waves (U5 to U30; 35 kHz) for given applications of time (5, 15 and 30 min), then the eggs were stored at 22°C for 14 days.
  
  
  RESULTS
  Depending on the time of ultrasonic application, a significant increase in egg shell strength (P < 0.01) was recorded. The highest value of the Haugh unit (67.93, 1 day) was observed on the eggs which were washed by ultrasonic waves. Yolk width values of ultrasonic washed eggs diminished. E. coli was completely removed by 30 min of ultrasonic application. During storage E. coli growth was not detected on the eggs which were washed by ultrasonic waves except the eggs in U5 group (2.04 log CFU eggshell⁻¹) on the first day of storage.
  
  
  CONCLUSIONS
  Depending on the time of ultrasonic application a significant increase in egg quality parameters (shell strength, albumen height, Haugh units, and yolk height) were observed. The application of ultrasound led to a significant reduction in E. coli numbers on egg shells.
authors.affiliation: Faculty of Engineering and Architecture, Department of Food Engineering, Necmettin Erbakan University, Konya 42090, Turkey. dsert@konya.edu.tr
authors.forename: Durmus
authors.initials: D
authors.lastname: Sert
authors.forename: Ali
authors.initials: A
authors.lastname: Aygun
authors.forename: Emrah
authors.initials: E
authors.lastname: Torlak
authors.forename: Emin
authors.initials: E
authors.lastname: Mercan
mesh_terms: D000818:Animals; D055598:Chemical Phenomena; D002645:Chickens; D003080:Cold Temperature; D015169:Colony Count, Microbial; D004528:Egg Shell / Q000737:chemistry / Q000000981:diagnostic imaging* / Q000382:microbiology; D004529:Egg White / Q000737:chemistry; D004530:Egg Yolk / Q000737:chemistry / Q000000981:diagnostic imaging; D004531:Eggs / Q000032:analysis / Q000382:microbiology*; D004926:Escherichia coli / Q000254:growth & development* / Q000302:isolation & purification; D005519:Food Preservation; D063427:Food Quality; D061353:Food Storage; D006863:Hydrogen-Ion Concentration; D055595:Mechanical Phenomena; D050296:Microbial Viability; D010858:Pigmentation; D013499:Surface Properties; D013997:Time Factors; D014465:Ultrasonics / Q000379:methods; D014463:Ultrasonography
keywords: Esherichia coli; Haugh unit; shell eggs; ultrasonic treatment