Validation of UV coiled tube reactor for fresh juices
The objective of this study was to validate the performance of a coiled ultraviolet (UV) module with 24 lamps for fresh juice pasteurization. Escherichia coli K12 at an inoculation level of 10 6 cfu mL -1 was chosen as a target microorganism for biodosimetry. All tested fruit juices highly absorbed...
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Published in | Journal of environmental engineering and science Vol. 6; no. 3; pp. 319 - 328 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Ottawa, Canada
NRC Research Press
01.05.2007
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Subjects | |
Online Access | Get full text |
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Summary: | The objective of this study was to validate the performance of a coiled ultraviolet (UV) module with 24 lamps for fresh juice pasteurization. Escherichia coli K12 at an inoculation level of 10
6
cfu mL
-1
was chosen as a target microorganism for biodosimetry. All tested fruit juices highly absorbed UV light, with absorption coefficients ranging from 11 cm
-1
to 78 cm
-1
for lillikoi and pineapple juice, respectively. Of the juices examined, pineapple juice appeared to be the worst case scenario in terms of UV absorptivity and high viscosity. A caramel model solution was developed to mimic juice absorption properties and was used for inoculation studies. The 5-log
10
reduction standard under turbulent flow required by the FDA was achievable in Newtonian liquids with absorption coefficient less than 15 cm
-1
after one pass. Turbulent flow was not developed in more viscous orange and pineapple juices at the flow rates tested. A biodosimetry technique that utilizes E. coli as a tracer showed no distribution of UV dose in liquids with absorption coefficient lower than 26 cm
-1
. The proposed technique may assist in validating the performance of UV reactors and improve efficiency of UV pasteurization. Key words: coiled ultraviolet module, fruit juices, caramel model, E. coli K12, biodosimetry. |
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Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 ObjectType-Article-2 ObjectType-Feature-1 |
ISSN: | 1496-256X 1496-2551 1496-256X |
DOI: | 10.1139/s06-058 |