Journal article
Ultraviolet-C light inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on organic fruit surfaces
International journal of food microbiology, Vol.210, pp.136-142
10/01/2015
Handle:
https://hdl.handle.net/2376/101384
PMID: 26122954
Abstract
This study investigated UV-C light inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on the surface of organic apples, pears, strawberries, red raspberries and cantaloupes. Fruit surfaces spot inoculated with cocktail strains of E. coli O157:H7 and L. monocytogenes were exposed to UV-C doses up to 11.9kJ/m2 at 23°C. Fruit surface roughness, contact angle, and surface energy were determined and correlated with UV-C inactivation kinetics.
Results demonstrate that bacterial pathogens on fruit surfaces respond differently to UV-C light exposure. E. coli O157:H7 on apple and pear surfaces was reduced by 2.9 and 2.1logCFU/g, respectively when treated with UV-C light at 0.92kJ/m2 (60s). For berries, the reduction of E. coli O157:H7 was lower with 2.0 (strawberry) and 1.1logCFU/g (raspberry) achieved after UV-C treatment at 7.2kJ/m2 (8min) and at 10.5kJ/m2 (12min), respectively. Similarly, a higher reduction of L. monocytogenes was observed on apple (1.6logCFU/g at 3.75kJ/m2) and pear (1.7logCFU/g at 11.9kJ/m2) surfaces compared to cantaloupe and strawberry surfaces (both achieved 1.0logCFU/g at 11.9kJ/m2). L. monocytogenes shows more resistance than E. coli O157:H7. Inactivation rates were higher for less hydrophobic fruits with smoother surfaces (apples and pears) as compared to fruits with rougher surfaces (cantaloupe, strawberry and raspberry). Findings indicate that UV-C light can effectively reduce E. coli O157:H7 and L. monocytogenes populations on fruit and berry surfaces. However, surface characteristics influence the efficacy of UV-C light.
•L. monocytogenes showed more UV-C resistance than E. coli O157:H7.•UV-C inactivation of pathogens was more effective on smoother surfaces.•E. coli and L. monocytogenes reduced by 2.9 and 1.6logCFU/g, respectively on apple.•A maximum of 1.1logCFU/g reduction of E. coli was observed on raspberry.•L. monocytogenes reduced by maximum 1.0logCFU/g on strawberry and cantaloupe.
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Details
- Title
- Ultraviolet-C light inactivation of Escherichia coli O157:H7 and Listeria monocytogenes on organic fruit surfaces
- Creators
- Achyut Adhikari - School of Nutrition and Food Sciences, Louisiana State University AgCenter, 263 Knapp Hall, Baton Rouge, LA 70803-6202, United StatesRoopesh M Syamaladevi - Biological Systems Engineering Department, Washington State University, P.O. Box 646120, Pullman WA 99164-6120, United StatesKaren Killinger - School of Food Science, Washington State University, P.O. Box 646376, Pullman, WA 99164-6376, United StatesShyam S Sablani - Biological Systems Engineering Department, Washington State University, P.O. Box 646120, Pullman WA 99164-6120, United States
- Publication Details
- International journal of food microbiology, Vol.210, pp.136-142
- Academic Unit
- Biological Systems Engineering, Department of
- Publisher
- Elsevier B.V
- Identifiers
- 99900546513001842
- Language
- English
- Resource Type
- Journal article