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PULSED LIGHT INACTIVATION OF MURINE NOROVIRUS ON VARIOUS FOOD CONTACT SURFACES
Title
PULSED LIGHT INACTIVATION OF MURINE NOROVIRUS ON VARIOUS FOOD CONTACT SURFACES
Creator
Zhou, Zijin
Date
2015, 2015-07
Description
Norovirus is one of the leading causes for foodborne illness. Transmission of virus from surface to food has been known to cause a number of...
Show moreNorovirus is one of the leading causes for foodborne illness. Transmission of virus from surface to food has been known to cause a number of outbreaks. Studies of norovirus have been conducted using Murine Norovirus to simulate the behaviors. Pulsed light (PL) is a promising surface decontamination technology, which has the potential to be applied in a food service setting. PL uses intense pulses of short duration and a broad spectrum to accomplish microbial inactivation. This study evaluates the effect of PL on MNV-1, artificially inoculated onto various food contact surfaces including 304 stainless steel, glazed tile, polypropylene, and ultra-high molecular weight (UHMW) polyethylene. The virus was allowed to inoculate on the coupons for 20mins and treated with PL in a Xenon Steripulse XL-3000TM pulsed light treatment system for up to 60 s, at a distance of 8.3 cm 10.8 cm or 13.3cm from the central axis of the lamp. An infrared (IR) camera was used to record surface temperatures, in 1-s increments. After PL treatments, remaining viruses were recovered from surfaces and quantified by plaque assay. At a distance of 10.8cm, MNV-1 was reduced by 2.22-, 2.27- 2.75- and 3.12-log, after 20s treatment on inoculated stainless steel, glazed tile, UHMW polyethylene and polypropylene, respectively. After 50s treatment, MNV-1 was reduced by 4.86- and 5.93- log on glazed tile and stainless steel surface respectively. The surface temperature on tile and stainless steel increased at the rate of 1.08±0.20 and 1.28±0.32°C /s respectively. A relatively short treatment using pulsed light is sufficient to inactivate MNV-1 on the surface of materials commonly used in food preparation. The results suggest that the technology has the potential to reduce surface viral contamination in a food preparation setting.
M.S. in Food Safety and Technology, July 2015
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IN-PACKAGE DECONTAMINATION OF SALMONELLA MONTEVIDEO ON BLACK PEPPER USING PULSED LIGHT TECHNOLOGY
Title
IN-PACKAGE DECONTAMINATION OF SALMONELLA MONTEVIDEO ON BLACK PEPPER USING PULSED LIGHT TECHNOLOGY
Creator
Xu, Xinran
Date
2016, 2016-07
Description
This study evaluated the efficacy of three pulsed light systems (1.8, 3 and 100 Hz) for inactivation of Salmonella Montevideo on the surface...
Show moreThis study evaluated the efficacy of three pulsed light systems (1.8, 3 and 100 Hz) for inactivation of Salmonella Montevideo on the surface of black pepper. The impact of frequency, treatment time and distance from the lamp on the rate of inactivation was studied. A reduction of 4.21 1og10 CFU/g was achieved with a 35 s treatment at 16.6-cm from lamp at 1.8 Hz. Similarly, reductions of 4.72 CFU/g and 4.70 CFU/g were obtained at 14.1-cm after 35 s treatment at 3 Hz and 100 Hz, respectively. Temperature measurement of packed and unpacked black pepper indicated that packaging material absorbed a small amount of energy. Measurement of surface and internal temperature suggested that temperature below the surface increased far less than surface temperature. For instance, temperature on the surface of the black pepper can go up to 200 °C as measured by the infrared camera within 30 to 40 s treatment. However, the temperature at 1 mm below the surface was up to 100 °C depending upon the distance from the lamp. The color of the black pepper did not change after pulsed light treatment (p>0.05). These results suggest that pulsed light can potentially be used to inactivate pathogens on black pepper surface without adversely affecting its quality.
M.S. in Food Safety and Technology, July 2016
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