1) Department of Food Engineering, Faculty of Engineering, Sivas Cumhuriyet University, Sivas, Turkey; 2) Department of Chemistry, Faculty of Science, Sivas Cumhuriyet University, Sivas, Turkey; 3) Department of Chemical Engineering, Faculty of Engineering, Sivas Cumhuriyet University, Sivas, Turkey; 4) Agricultural and Biological Engineering, The Pennsylvania State University, University Park, PA 16802, USA
Surface decontamination of white cheese by pulsed UV light treatment
Oberflächendekontamination von Weißkäse durch gepulste UV-Lichtbehandlung
Nene Meltem Keklik1), Adil Elik2), Uğur Salgin3), Ali Demirci4), Gamze Koçer1)
Summary
Surface contamination of cheese varieties with pathogenic microorganisms is a potential risk in dairy industry. Pulsed UV (PUV) light is a method, which provides rapid inactivation of a wide range of microorganisms on foods. In this study, white cheese inoculated on top surface with Staphylococcus aureus or Escherichia coli O157:H7 was exposed to PUV light. Treatment parameters were time (5, 15, 30, 45, 60 s) and distance from the quartz window of xenon lamp (5, 8, 13 cm). The 60 s-8 cm treatment (91.22 J/cm2) resulted in the highest inactivation level without visually altering the appearance of white cheese. After this treatment, approximately 1.31 and 2.20 log10 reductions (cfu/cm2) were obtained for S. aureus and E. coli O157:H7, respectively. Lipid oxidation, pH, and moisture content, except the color parameters, remained unchanged (p>0.05) after the 60 s-8 cm treatment. Only 1.75 % of the PUV light reached to a depth of 0.5 cm in white cheese after treatment at 5 cm. These findings indicate that although PUV light is able to reduce pathogen counts of white cheese, this technology can only be utilized for surface decontamination.
Keywords: Escherichia coli O157:H7, Staphylococcus aureus, microbial inactivation, pulsed UV light, white cheese
Korrespondenzadresse E-Mail
meltemkeklik@gmail.com
Weitere Informationen zum Beitrag
Arch Lebensmittelhyg 71,
86–92 (2020)
DOI 10.2376/0003-925X-71-86
Copyright
© M. & H. Schaper GmbH & Co.
ISSN 0003-925X