Microscopic and Spectroscopic Evaluation of Inactivation of Staphylococcus aureus by Pulsed UV Light and Infrared Heating

Krishnamurthy, Kathiravan; Tewari, Jagdish; Irudayaraj, Joseph; Demirci, Ali

doi:10.1007/s11947-008-0084-8

Cited by 173 publications

(83 citation statements)

References 24 publications

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“…According to Fine and Gervais (2004), this overheating may cause vaporization and generate a small steam flow to cause membrane destruction. Krishnamurthy et al (2008) also suggested photophysical effects of PL on S. aureus in phosphate buffer treated for 5 s, caused by disturbances of intermittent high energy pulses, since temperature increase during treatment was negligible (2°C). S. aureus exhibited cell wall damage, cytoplasmic membrane shrinkage, cellular content leakage, and mesosome disintegration based on transmission electron microscopy and Fourier transform infrared spectroscopy observations.…”

Section: Microbial Inactivation By Plmentioning

confidence: 95%

Pulsed Light Treatments for Food Preservation. A Review

Oms‐Oliu

Martı́n-Belloso

Soliva‐Fortuny

2008

Food Bioprocess Technol

302

145

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Consumers demand high-quality processed foods with minimal changes in nutritional and sensory properties. Nonthermal methods are considered to keep food quality attributes better than traditional thermal processing. Pulsed light (PL) is an emerging nonthermal technology for decontamination of food surfaces and food packages, consisting of short time high-peak pulses of broad spectrum white light. It is considered an alternative to continuous ultraviolet light treatments for solid and liquid foods. This paper provides a general review of the principles, mechanisms of microbial inactivation, and applications of PL treatments on foods. Critical process parameters that are needed to be optimized for a better efficiency of PL treatments are also discussed. PL has considerable potential to be implemented in the food industry. However, technological problems need to be solved in order to avoid food overheating as well as to achieve better penetration and treatment homogeneity. In addition, a more extensive research is needed to understand how PL affects quality food attributes.

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Section: Microbial Inactivation By Plmentioning

confidence: 95%

Pulsed Light Treatments for Food Preservation. A Review

Oms‐Oliu

Martı́n-Belloso

Soliva‐Fortuny

2008

Food Bioprocess Technol

302

145

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“…Attempts to elucidate the mechanism by which pulsed light kills bacteria and yeasts have been published (10,(53)(54)(55)(56)(57). In the present study, multiple assays were performed to provide insight into the mechanism of virus inactivation by pulsed light.…”

Section: CMmentioning

confidence: 99%

Efficacy and Mechanisms of Murine Norovirus Inhibition by Pulsed-Light Technology

Vimont

Fliss

Jean

2015

Appl Environ Microbiol

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Pulsed light is a nonthermal processing technology recognized by the FDA for killing microorganisms on food surfaces, with cumulative fluences up to 12 J cm ؊2 . In this study, we investigated its efficacy for inactivating murine norovirus 1 (MNV-1) as a human norovirus surrogate in phosphate-buffered saline, hard water, mineral water, turbid water, and sewage treatment effluent and on food contact surfaces, including high-density polyethylene, polyvinyl chloride, and stainless steel, free or in an alginate matrix. The pulsed-light device emitted a broadband spectrum (200 to 1,000 nm) at a fluence of 0.67 J cm ؊2 per pulse, with 2% UV at 8 cm beneath the lamp. Reductions in viral infectivity exceeded 3 log 10 in less than 3 s (5 pulses; 3.45 J cm ؊2 ) in clear suspensions and on clean surfaces, even in the presence of alginate, and in 6 s (11 pulses; 7.60 J cm ؊2 ) on fouled surfaces except for stainless steel (2.6 log 10 ). The presence of protein or bentonite interfered with viral inactivation. Analysis of the morphology, the viral proteins, and the RNA integrity of treated MNV-1 allowed us to elucidate the mechanisms involved in the antiviral activity of pulsed light. Pulsed light appeared to disrupt MNV-1 structure and degrade viral protein and RNA. The results suggest that pulsed-light technology could provide an effective alternative means of inactivating noroviruses in wastewaters, in clear beverages, in drinking water, or on food-handling surfaces in the presence or absence of biofilms.H uman noroviruses are responsible for one-fifth of all cases of acute gastroenteritis worldwide (1). They spread directly via person-to-person contact (fecal-oral and vomitus-oral) or indirectly through food, water, and the environment (2). Natural biofilms in sewage treatment effluent could be responsible for many persistent waterborne outbreaks, since such biofilms have been found to harbor noroviruses (3, 4). Infection spreads quickly and widely, affecting individuals of all ages, especially where many people gather or live in close proximity, such as in long-term care residences, retirement homes, cruise ships, and the like. Infectious doses as low as 2,800 particles, the high viral loads in feces and vomit (up to 10 9 genomic copies per gram), persistence in the environment, prolonged duration of viral shedding even after symptoms have resolved, and inadequate long-term immunity all contribute to the high incidence of norovirus illness (5). Although the illness is usually mild and self-limiting, the large number of cases per year represents a considerable loss in productivity and constitutes a substantial burden on society (2, 6).Among the physical disinfection processes, pulsed-light treatment appears well suited for the disinfection of food contact surfaces in industrial and health care settings and for decontaminating water and beverages. It has been proposed as a means of nonthermal pasteurization for food preservation and for decontaminating air and packaging materials (7). It has proven effective for inactivati...

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“…IR heating can be also used to inactivate bacteria, spores, yeast, and molds in both liquid and solid for drying low moisture foods and baking of rice cakes (Sarantinos and Black 1996;Zarkadas and Wiseman 2001;Krishnamurthy et al 2009;Turabi et al 2008;Sabanis and Tria 2009).…”

Section: Introductionmentioning

confidence: 99%

Influence of Infrared Treatment on Mechanical Strength and Structure of Wheat Grains

Andrejko

Grochowicz

Goździewska

et al. 2009

Food Bioprocess Technol

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The paper presents the relationship between the parameters (temperature and time) of infrared heating and wheat grain compressive resistance. Additionally, an attempt to explain the mechanism of decrease in the strength of grain under thermal processing was undertaken. Based on the results obtained, we reached the conclusion that thermal processing with infrared (IR) radiation leads to a decrease in wheat grain compressive resistance. The range of compressive resistance changes depends on the temperature and the time that the wheat grain is exposed to IR radiation: The higher the temperature and the longer the processing time, the lower grain compressive resistance. The lowest values of compressive force were recorded following the process carried out at 180°C for 150 s. Changes of grain resistance are caused by damage done to their internal structure resulting from the thermal influence of infrared radiation. The damage scope is related to the temperature and processing time. There are particularly noticeable changes after processing at temperature above 150°C and time exceeding 90 s. In the course of the process carried out under these conditions (t>150°C, τ>90 s), a phenomenon of starch gelatinization occurs. Starch begins to gelatinize from the inside of the grains, which is characteristic of the absorption and heat transfer mechanisms occurring during electromagnetic wave heating.

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Microscopic and Spectroscopic Evaluation of Inactivation of Staphylococcus aureus by Pulsed UV Light and Infrared Heating

Cited by 173 publications

References 24 publications

Pulsed Light Treatments for Food Preservation. A Review

Pulsed Light Treatments for Food Preservation. A Review

Efficacy and Mechanisms of Murine Norovirus Inhibition by Pulsed-Light Technology

Influence of Infrared Treatment on Mechanical Strength and Structure of Wheat Grains

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