Preliminary communication
https://doi.org/10.17113/ftb.53.02.15.3966
The Efficiency of UVC Radiation in the Inactivation of Listeria monocytogenes on Beef-Agar Food Models
Amir M. Hamidi-Oskouei
; National Centre for Food Manufacturing, Holbeach Campus, University of Lincoln, Holbeach, United Kingdom
Christian James
; Food Refrigeration and Process Engineering Research Centre (FRPERC), Grimsby Institute (GIFHE), Nuns Corner, Grimsby, United Kingdom
Stephen James
; Food Refrigeration and Process Engineering Research Centre (FRPERC), Grimsby Institute (GIFHE), Nuns Corner, Grimsby, United Kingdom
Abstract
The aim of this study is to evaluate the eff ect of meat content and surface smoothness on the deactivation of Listeria monocytogenes in beef-agar food models achieved by shortwave ultraviolet (UVC) light. Food models with various meat contents were made using chopped beef slices and agar solution. Prepared models together with a Listeria selective agar (LSA) plate and a slice of cooked beef were inoculated with L. monocytogenes and then exposed to UVC light. Population of Listeria reduced to below the level of detection on the LSA plates. As the content of beef in the beef-agar models increased, more L. monocytogenes cells survived. Survival was greatest on the treated cooked slice of beef. To bett er understand the effect of surface irregularities, a white light interferometer was used to analyse the surface smoothness of beef-agar media and LSA plates. No correlation was observed between the surface roughness of seven out of nine types of produced beef-agar media and the degree of inactivation resulting from UVC radiation at the given dose, whereas, less bacterial cells were killed as beef content of the food models increased. The findings of the current study show that the chemical composition of the treated sample also plays an important role in pathogen resistance and survival, meaning that two samples with similar surface irregularities but diff erent chemical composition might produce very diff erent inactivation results when exposed to UVC light.
Keywords
Listeria monocytogenes; shortwave ultraviolet light (UVC); microbial deactivation; ready-to-eat beef; surface analysis; nonthermal decontamination
Hrčak ID:
140239
URI
Publication date:
23.6.2015.
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