Pulsed UV laser light on Escherichia coli and Saccharomyces cerevisiae suspended in non-alcoholic beer
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Abstract
Background: The aim of this study was to investigate the effect of pulsed ultra-violet (UV) irradiation on inactivation of beer spoilage microorganisms. UV irradiation is nowadays cost effective enough to compete with traditional biological, physical, and chemical treatment technologies and has become an alternative to such methods.
Material and Methods: Photoinactivation effects of pulsed UV laser with the wavelengths of 355 and 266 nm, which inactivate typical prokaryotic (Escherichia coli) and eukaryotic (Saccharomyces cerevisiae) microorganisms, were examined with different doses and exposure times.
Results: A dose of 100 J/cm2 of the 355 nm pulsed UV laser was able to reduce about 1 to 2 log (88.75%) of E.coli with the population of 1.6×108 colony-forming units (CFU/ml), and 97% of 3.2×107, 3×106, 5.5×105, and 9×104 CFU/ml. In the case of 266 nm, more than 99% reduction in E. coli serial dilutions was inactivated, using 10 J/cm2 with exception of 7×104 CFU/ml which was not detected any bacterial growth using 5 J/cm2. In addition, 50, 40, and 20 J/cm2 energy were used successfully to inactivate S. cerevisiae at the populations of 5.4×106, 7×105, 5×104 and 4×103 CFU/ml, respectively.
As a result, pulsed UV Laser with 266 nm was strong enough to inactivate a high titer of bacterial and yeast indicator standards suspended in non-alcoholic beer in comparison with 355nm doses.
Conclusion: Results indicate that pulsed UV technology, in principle, is an attractive alternative to conventional methods for the inactivation of indicator microorganisms and has potential in irradiation of unpasteurized beer.
Briggs DE, Boulton CA, Brooks PA, Stevens R (2004) Brewing Science and Practice. Cambridge CB1 6AH, England: Woodhead Publishing Limited and CRC Press, LLC.
HYDE A. Plate Pasteurization for Keg and Smallpack.The Brewer 2000; 86: 248-250.
Takeshita K, Shibato J, Sameshima T, Fukunaga S, Isobe S, Arihara K, et al. Damage of yeast cells induced by pulsed light irradiation. Int J Food Microbiol 2003;85: 151-158.
US FDA. Irradiation in the production, prcessing and handling of food. 21 CFR part 179. Fed Regist 2000;65: 71056-71058.
US FDA. Hazard analysis and critical control point (HAACP): Procedures for the safe and sanitary processing and importing of juice. Final rule. Fed Regist 2001; 66: 6137-6202.
US FDA. Guidance for Industry, Juice HACCP Hazards and Controls Guidance. 21 CFR part 120. Fed Regist 2004; 69: 10051.
Koutchma T, Murakami E, Adhikari C. Summary: UV disinfection of juices. Food Safety Watch. National Center for Food Safety and Technology 2002; 13:4.
Koutchma T, Keller S, Chirtel S, Parisi B. Ultraviolet disinfection of juice products in laminar and turbulent flow reactors. Innovative Food Science and Emerging Technologies 2004, 5: 179-189.
Sastry SK, Datta AK, Worobo RW. Ultraviolet light. J Food Sci. Suppl 2000; 65: 90-92.
Hanes DE, Worobo RW, Orlandi PA, Burr DH, Miliotis MD, Robl MG, et al. Inactivation of Cryptosporidium parvum oocysts in fresh apple cider by UV irradiation. Appl Environ Microbiol 2002; 68: 4168-4172.
Quintero-Ramos A, Churey JJ, Hartman P, Barnard J, Worobo RW. Modeling of Escherichia coli inactivation by UV irradiation at different pH values in apple cider. J Food Prot 2004; 67: 1153-1156.
Wright JR, Sumner SS, Hackney CR, Pierson MD, Zoecklein BW. Efficacy of ultraviolet light for reducing Escherichia coli O157:H7 in unpasteurized apple cider. J. Food Prot 2000; 63: 563-567.
Krishnamurthy K, Demirci A, Irudayaraj J. Inactivation of Staphylococcus aureus by pulsed UV-light sterilization. J Food Prot 2004; 67: 1027-1030.
Smith WL, Lagunas-Solar MC, Cullor JS. Use of pulsed ultraviolet laser light for the cold pasteurization of bovine milk. J Food Prot 2002; 65:1480-1482.
Krishnamurthy K, Demirci A, Irudayaraj JM.Inactivation of Staphylococcus aureus in Milk Using Flow-Through Pulsed UV-Light Treatment System. J Food Prot 2007; 72: 233-239.
Sosnin EA, Lavrent’eva LV, Yusupov MR, Masterova YV, Tarasenko VF (2002) Inactivation of escherichia coli using capacitive discharge excilamps. 2nd International Workshop on Biological Effects of Electromagnetic Field, Rhodes, Greece, pp 384-388.
Wang T, Macgregor SJ, Anderson JG, Woolsey GA.Pulsed ultraviolet inactivation spectrum of Echerichia coli. Water Res 2005; 39: 2921-2925.
Karimi Azar DaryaniM, Massudi R, Hosseini M. photoinactivation of Escherichia coli and Saccharomyces cervisiae suspended in Phosphate- Buffered Saline- A using 266- and 355-nm Pulsed Ultraviolet Light. Curr Microbiol 2008; 56: 423-428.
Oguma K, Katayama H, Ohgaki S. Photoreactivation of Escherichia col after low- or medium-pressure UV disinfection determined by an endonuclease sensitive site assay. Appl Environ Microbiol 2002; 68: 6029-6035.
Oppezzo OJ and Pizarro RJ. Sublethal effects of ultraviolet A radiation on Enterobacter cloacae. J Photochem Photobiol B 2001; 62: 158-165.
Petin VG, Kim JK, Rassokhina AV, Zhurakovskaya GP. Mitotic recombination and inactivation in Saccharomyces cerevisiae induced by UV-radiation (254 nm) and hyperthermia depend on UV fluence rate. Mutat Res 2001; 478: 169-176.
Rice JK and Ewell M. Examination of peak power dependence in the UV inactivation of bacterial spores.Appl Environ Microbiol 2001; 67: 5830-5832.
Vasilenko V. The pasteurization effect of laser infrared irradiation on beer. MBAA TQ 2001; 38: 212-215.
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| Issue | Vol 3 No 1 (2011) | |
| Section | Articles | |
| Keywords | ||
| Pulsed UV laser light Inactivation E coli S cerevisiae non alcoholic Beer | ||
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