Food Biophysics

, Volume 6, Issue 1, pp 170–182 | Cite as

Biophysical Evaluation of Food Decontamination Effects on Tissue and Bacteria

  • Ann Zahle AndersenEmail author
  • Lars Duelund
  • Jonathan Brewer
  • Pia Kiil Nielsen
  • Tina Birk
  • Kristine Garde
  • Birgitte Kallipolitis
  • Niels Krebs
  • Luis Bagatolli
Original Article


Traditionally, the effects and efficiency of food surface decontamination processes, such as chlorine washing, radiation, or heating, have been evaluated by sensoric analysis and colony-forming unit (CFU) counts of surface swabs or carcass rinses. These methods suffice when determining probable consumer responses or meeting legislative contamination limits. However, in the often very costly, optimization process of a new method, more quantitative and unbiased results are invaluable. In this study, we employed a biophysical approach for the investigation of qualitative and quantitative changes in both food surface and bacteria upon surface decontamination by SonoSteam®. SonoSteam® is a recently developed method of food surface decontamination, which employs steam and ultrasound for effective heat transfer and short treatment times, resulting in significant reduction in surface bacteria. We employ differential scanning calorimetry, second harmonics generation imaging microscopy, two-photon fluorescence microscopy, and green fluorescence protein-expressing bacteria and compare our results with those obtained by traditional methods of food quality and safety evaluations. Our results show that there are no contradictions between data obtained by either approach. However, the biophysical methods draw a much more nuanced picture of the effects and efficiency of the investigated decontamination method, revealing, e.g., an exponential dose/response relationship between SonoSteam® treatment time and changes in collagen I, and a depth dependency in bacterial reduction, which points toward CFU counts overestimating total bacterial reduction. In conclusion, the biophysical methods provide a less biased, reproducible, and highly detailed system description, allowing for focused optimization and method validation.


Differential scanning calorimetry Second-harmonic generation imaging microscopy Collagen Campylobacter jejuni Listeria monocytogenes Escherichia coli 



The authors wish to thank Maria Bloksgaard Mølgaard and Maria In\(\acute{e}\)s Plasencia Gil at Memphys, SDU for their invaluable help and advice during the initial phase of this investigation.


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Copyright information

© Springer Science+Business Media, LLC 2011

Authors and Affiliations

  • Ann Zahle Andersen
    • 1
    Email author
  • Lars Duelund
    • 2
  • Jonathan Brewer
    • 2
    • 3
  • Pia Kiil Nielsen
    • 1
  • Tina Birk
    • 4
  • Kristine Garde
    • 5
  • Birgitte Kallipolitis
    • 1
  • Niels Krebs
    • 5
  • Luis Bagatolli
    • 2
    • 3
  1. 1.Department of Biochemistry and Molecular BiologyUniversity of Southern Denmark (SDU)Odense MDenmark
  2. 2.Memphys, Department of Physics and ChemistryOdense M, SDUDenmark
  3. 3.Membrane Biophysics and Biophotonics Group, Department of Biochemistry and Molecular BiologySDU, Odense MDenmark
  4. 4.Department of Microbiology and Risk Assessment, National Food InstituteTechnical University of DenmarkSøborgDenmark
  5. 5.SonoSteam, FORCE TechnologyBrøndbyDenmark

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