Food Protection Trends - September/October 2022 - 377

PEER-REVIEWED ARTICLE
Jessie Usaga,1,2*
Wendy Beauvais,3,4
John J. Churey,1
Juan Enciso,7 Juan R. Anciso,9
April K Englishbey,5†
Cristina Marchesan Marconi,6‡ Uriel Cholula,7§ Alexandra M. Belias,8
Michelle Wemette,3
Randy W. Worobo,1
Kendra Nightingale,5 and Renata Ivanek3
1Dept. of Food Science, College of Agriculture and Life Sciences, Cornell University, Geneva, NY 14456, USA
2
3
National Center of Food Science and Technology, University of Costa Rica, Ciudad Universitaria Rodrigo Facio,
11501-2060, Costa Rica
Dept. of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY
14850, USA
4Dept. of Comparative Pathobiology, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA
5Animal and Food Sciences, Texas Tech University, Lubbock, TX 79415, USA
6Texas A&M AgriLife Research, Weslaco, TX 78596, USA
7
Biological and Agricultural Engineering, College of Agriculture and Life Sciences, Texas A&M University, College
Station, TX 77843, USA
8Dept. of Food Science, College of Agriculture and Life Sciences, Cornell University, Ithaca, NY 14853, USA
9Dept. of Horticultural Sciences, Texas A&M AgriLife Extension Service, Weslaco, TX 78596, USA
Present address: Hygiena LLC, Camarillo, CA 93012, USA
†
‡
Present address: College of Agriculture and Life Sciences, North Carolina State University, IR-4 Project, Raleigh, NC
27607, USA
§Present address: Dept. of Agriculture, Veterinary and Rangeland Sciences, University of Nevada, Reno, NV 89557, USA
Copyright©
Food Protection Trends, Vol 42, No. 5, p. 377-382
https://doi.org/10.4315/FPT-22-003
2022, International Association for Food Protection
2900 100th Street, Suite 309, Des Moines, IA 50322-3855, USA
Inactivation of Salmonella and Escherichia coli in Surface
Agricultural Water Using a Commercial UV Processing Unit
ABSTRACT
Treatment of agricultural water aids in the prevention
of foodborne disease outbreaks linked to contaminated
fresh produce. UV light is a suitable alternative for treating
drinking water but is not always effective for surface
irrigation water due to interference caused by turbidity and
high microbial loads. The effectiveness of UV treatment
for reducing Escherichia coli and Salmonella in surface
water used in agriculture was evaluated. Six pond water
samples were collected on each of 16 sampling dates over
a 3-year period. On each corresponding testing date, three
samples were inoculated with Salmonella enterica serovars
Hartford, Montevideo, and Gaminara and the other
three samples were inoculated with E. coli ATCC 25922,
targeting a concentration of 7 log CFU/mL. Inoculated
water was UV treated with a commercially available juice
processing UV device at a constant UV dose of 14.2 mJ/
cm2
and a turbulent flow regime. The effects of date,
initial bacterial counts, and water pH and turbidity on
log reductions of both microorganisms were determined.
Initial bacterial counts and test date significantly predicted
microbial reduction (multivariate P < 0.001), but neither
pH nor turbidity influenced microbial reductions (P > 0.05).
UV treatment reduced both Salmonella and E. coli by a
mean of >6 log CFU/mL.
INTRODUCTION
Several foodborne disease outbreaks due to consumption
of contaminated fresh produce have been reported in past
years worldwide (3, 4, 10). Many of these cases have been
linked to untreated contaminated irrigation water and include
outbreaks due to the consumption of jalapeno and serrano
peppers, alfalfa sprouts, tomato, lettuce, and cauliflower
contaminated with Salmonella or Escherichia coli O157:H7
(14). Agricultural water is one of the main vehicles by which
pathogenic microorganisms reach fresh produce (3), and the
risk of contamination increases when untreated surface water
is used for irrigation (8, 11). About 52% of the water used for
irrigation in the United States is surface water (5).
Improved food safety practices, including water treatment
and microbial water quality monitoring, are some of the currently
applied preventive and mitigation strategies for reduc*Author
for correspondence: Phone: +1 506.2511.3465; Email: jessie.usaga@ucr.ac.cr
September/October Food Protection Trends 377

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