Effect of Temperature and Relative Humidity on the Survival of Foodborne Viruses during Food Storage

ABSTRACTMillions of people suffer from foodborne diseases throughout the world every year, and the importance of food safety has grown worldwide in recent years. The aim of this study was to investigate the survival of hepatitis A virus (HAV) and viral surrogates of human norovirus (HuNoV) (bacteriophage MS2 and murine norovirus [MNV]) in food over time. HAV, MNV, and MS2 were inoculated onto either the digestive gland of oysters or the surface of fresh peppers, and their survival on these food matrices was measured under various temperature (4°C, 15°C, 25°C, and 40°C) and relative humidity (RH) (50% and 70%) conditions. Inoculated viruses were recovered from food samples and quantified by a plaque assay at predetermined time points over 2 weeks (0, 1, 3, 7, 10, and 14 days). Virus survival was influenced primarily by temperature. On peppers at 40°C and at 50% RH, >4- and 6-log reductions of MNV and HAV, respectively, occurred within 1 day. All three viruses survived better on oysters. In addition, HAV survived better at 70% RH than at 50% RH. The survival data for HAV, MS2, and MNV were fit to three different mathematical models (linear, Weibull, and biphasic models). Among them, the biphasic model was optimum in terms of goodness of fit. The results of this study suggest that major foodborne viruses such as HAV and HuNoV can survive over prolonged periods of time with a limited reduction in numbers. Because a persistence of foodborne virus on contaminated foods was observed, precautionary preventive measures should be performed.

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Kinetics of Gelatinized White Yam (Dioscorea Rotundata, Poir) During Convective Drying

FUOYE Journal of Engineering and Technology ◽

10.46792/fuoyejet.v2i2.127 ◽

2017 ◽

Vol 2 (2) ◽

Author(s):

Adesola A Satimehin

Keyword(s):

Relative Humidity ◽

Goodness Of Fit ◽

Convective Drying ◽

Effect Of Temperature ◽

Constant Rate ◽

Thin Layer Drying ◽

White Yam ◽

Rate Period ◽

Drying Models ◽

Binomial Approximation

Gelatinized white yam cubes, having a moisture content of 196% dry basis were dried in a convective dryer under different conditions of air temperature (40, 50, 60 and 70°C) and relative humidity (20 - 50%). There was no constant rate period throughout the entire drying period as drying took place entirely during a falling rate period. The effect of temperature was more pronounced than that of relative humidity. The drying data were fitted to five thin-layer drying models. The goodness of fit of the models were evaluated by comparing the percent mean relative deviation modulus (E%), RMSE, χ2 and R2 between their observed and predicted moisture ratio. The Binomial approximation of Fick's diffusion equation gave the best fit to the drying data as the highest values of R2 and the lowest values of χ2 and RMSE were consistently obtained with the Binomial model equation.

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Survival and Inactivation by Advanced Oxidative Process of Foodborne Viruses in Model Low-Moisture Foods

Food and Environmental Virology ◽

10.1007/s12560-020-09457-7 ◽

2021 ◽

Vol 13 (1) ◽

pp. 107-116

Author(s):

Neda Nasheri ◽

Jennifer Harlow ◽

Angela Chen ◽

Nathalie Corneau ◽

Sabah Bidawid

Keyword(s):

Ambient Temperature ◽

Hepatitis A Virus ◽

Plaque Assay ◽

Oxidative Process ◽

Limited Information ◽

Foodborne Viruses ◽

Log Reduction ◽

Viral Survival ◽

Low Moisture Foods ◽

Advanced Oxidative Process

AbstractEnteric viruses, such as human norovirus (NoV) and hepatitis A virus (HAV), are the major causes of foodborne illnesses worldwide. These viruses have low infectious dose, and may remain infectious for weeks in the environment and food. Limited information is available regarding viral survival and transmission in low-moisture foods (LMF). LMFs are generally considered as ready-to-eat products, which undergo no or minimal pathogen reduction steps. However, numerous foodborne viral outbreaks associated with LMFs have been reported in recent years. The objective of this study was to examine the survival of foodborne viruses in LMFs during 4-week storage at ambient temperature and to evaluate the efficacy of advanced oxidative process (AOP) treatment in the inactivation of these viruses. For this purpose, select LMFs such as pistachios, chocolate, and cereal were inoculated with HAV and the norovirus surrogates, murine norovirus (MNV) and feline calicivirus (FCV), then viral survival on these food matrices was measured over a four-week incubation at ambient temperature, by both plaque assay and droplet-digital RT-PCR (ddRT-PCR) using the modified ISO-15216 method as well as the magnetic bead assay for viral recovery. We observed an approximately 0.5 log reduction in viral genome copies, and 1 log reduction in viral infectivity for all three tested viruses following storage of select inoculated LMFs for 4 weeks. Therefore, the present study shows that the examined foodborne viruses can persist for a long time in LMFs. Next, we examined the inactivation efficacy of AOP treatment, which combines UV-C, ozone, and hydrogen peroxide vapor, and observed that while approximately 100% (4 log) inactivation can be achieved for FCV, and MNV in chocolate, the inactivation efficiency diminishes to approximately 90% (1 log) in pistachios and 70% (< 1 log) in cereal. AOP treatment could therefore be a good candidate for risk reduction of foodborne viruses from certain LMFs depending on the food matrix and surface of treatment.

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Effect of Process Temperature on Virus Inactivation during High Hydrostatic Pressure Processing of Contaminated Fruit Puree and Juice

Journal of Food Protection ◽

10.4315/0362-028x.jfp-16-004 ◽

2016 ◽

Vol 79 (9) ◽

pp. 1517-1526 ◽

Cited By ~ 3

Author(s):

HAO PAN ◽

MATTHEW BUENCONSEJO ◽

KARL F. REINEKE ◽

Y. CAROL SHIEH

Keyword(s):

Hepatitis A ◽

Initial Temperature ◽

Hepatitis A Virus ◽

High Pressure Processing ◽

Effect Of Temperature ◽

Virus Inactivation ◽

Murine Norovirus ◽

Log Reduction ◽

High Hydrostatic Pressure Processing ◽

Holding Temperature

ABSTRACT High pressure processing (HPP) can inactivate pathogens and retain fruit qualities. Elevated HPP pressure or time increases virus inactivation, but the effect of temperature is not consistently observed for norovirus and hepatitis A virus. In the present study, the effectiveness of HPP holding temperatures (<40°C) and pressures were evaluated for inactivating surrogates (murine norovirus [MNV] and MS2 coliphage) in pomegranate and strawberry juices and strawberry puree using a 24-liter HPP system. The holding temperature was established by setting the HPP initial temperature via pretrials. All trials were able to arrive at the designated holding pressure and holding temperature simultaneously. MNV inactivation in juices was conducted at 300 MPa for 3 min with various holding temperatures (10 to 30°C). A regression equation was derived, Y = −0.08 × X + 2.6 log PFU, R2 = 0.96, where Y is the log reduction and X is the holding temperature. The equation was used to predict a 2.6-log reduction in juices at 0°C holding temperature and indicated that MNV inactivation was inversely proportional to temperature increase. MNV survival during HPP did not differ significantly in pomegranate and strawberry juices. However, MS2 coliphage inactivation was greater as the holding temperature increased (from 15 to 38°C) at 600 MPa for 3 min. The increased inactivation trend is presumably similar to that for hepatitis A virus, but the holding temperature was not correlated with the reduction of HPP-resistant MS2 in strawberry puree. When the HPP holding pressure was evaluated independently in strawberry puree, a 5-log reduction of MNV was predicted through regression analysis at the holding pressure of 424 MPa for 3 min at 20°C. These parameters should inactivate >5 log PFU of MNV in juices, based upon a greater inactivation in berry juice than in puree (1.16-versus 0.74-log reduction at 300 MPa). This research illustrates use of predictive inactivation and a feasible means for manipulating HPP parameters for effective virus inactivation in fruit juices and puree.

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Thermal Inactivation of Enteric Viruses and Bioaccumulation of Enteric Foodborne Viruses in Live Oysters (Crassostrea virginica)

Applied and Environmental Microbiology ◽

10.1128/aem.03573-15 ◽

2016 ◽

Vol 82 (7) ◽

pp. 2086-2099 ◽

Cited By ~ 28

Author(s):

Elbashir Araud ◽

Erin DiCaprio ◽

Yuanmei Ma ◽

Fangfei Lou ◽

Yu Gao ◽

...

Keyword(s):

Heat Treatment ◽

Receptor Binding ◽

Thermal Inactivation ◽

Hepatitis A Virus ◽

Enteric Viruses ◽

Heat Stability ◽

Magnetic Bead ◽

Murine Norovirus ◽

Foodborne Viruses ◽

Porcine Gastric Mucin

ABSTRACTHuman enteric viruses are among the main causative agents of shellfish-associated outbreaks. In this study, the kinetics of viral bioaccumulation in live oysters and the heat stabilities of the predominant enteric viruses were determined both in tissue culture and in oyster tissues. A human norovirus (HuNoV) GII.4 strain, HuNoV surrogates (murine norovirus [MNV-1], Tulane virus [TV]), hepatitis A virus (HAV), and human rotavirus (RV) bioaccumulated to high titers within oyster tissues, with different patterns of bioaccumulation for the different viruses. We tested the thermal stability of each virus at 62, 72, and 80°C in culture medium. The viruses can be ranked from the most heat resistant to the least stable as follows: HAV, RV, TV, MNV-1. In addition, we found that oyster tissues provided protection to the viruses during heat treatment. To decipher the mechanism underlying viral inactivation by heat, purified TV was treated at 80°C for increasing time intervals. It was found that the integrity of the viral capsid was disrupted, whereas viral genomic RNA remained intact. Interestingly, heat treatment leading to complete loss of TV infectivity was not sufficient to completely disrupt the receptor binding activity of TV, as determined by the porcine gastric mucin–magnetic bead binding assay. Similarly, HuNoV virus-like particles (VLPs) and a HuNoV GII.4 strain retained some receptor binding ability following heat treatment. Although foodborne viruses have variable heat stability, 80°C for >6 min was sufficient to completely inactivate enteric viruses in oysters, with the exception of HAV.

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Effect of Plant-derived Proteases on Infectivity of Tulane Virus, Murine Norovirus, and Hepatitis A Virus

Journal of Food Protection ◽

10.4315/jfp-20-296 ◽

2020 ◽

Author(s):

Adrienne Shearer ◽

Kalmia Kniel

Keyword(s):

Time Course ◽

Hepatitis A ◽

Elevated Temperatures ◽

Hepatitis A Virus ◽

Plaque Assay ◽

Antimicrobial Properties ◽

Specific Treatment ◽

Murine Norovirus ◽

Current Application ◽

Tulane Virus

Plant-derived proteases, bromelain, papain, and ficin are broad-acting enzymes with generally recognized as safe (GRAS) status for foods and have current application in several food industries. These proteases have also been reported to have antimicrobial properties. This study investigated the efficacy of commercially-prepared bromelain, papain, and ficin, individually and combined (2500 ppm crude extract), for inactivation of hepatitis A virus (HAV) and HuNoV surrogates, Tulane virus (TV), and murine norovirus (MNV). Various treatment temperatures (45, 50, 55°C), times (10 or 60 min), and pH values (5.5, 7.0) in the presence of cysteine (2 mM) were evaluated. Inactivation was assessed by infectivity in plaque assay for TV and MNV and by TCID50 for HAV. No reduction in infectious TV or HAV was attributed to the plant-derived proteases at any of the conditions tested. Infectious MNV was reduced by one to 3 log10 PFU/ml; the most effective treatment was bromelain at pH 7 and 50°C for 10 minutes. A time course study with MNV in bromelain at 50°C indicated that a 2-log10 PFU/ml reduction could be achieved within 6 minutes, but extended treatment of 15 minutes was still insufficient to eliminate infectious MNV. The lack of or limited efficacy of bromelain, papain, and ficin on HAV, TV, and MNV even at elevated temperatures and exposure times suggests the plant-derived proteases are not commercially applicable for inactivation of virus on commodities or materials that could not also withstand mild heat treatment. The variable susceptibilities observed between TV and MNV illustrate limitations in utilization of surrogates for predicting pathogen behavior for a structure-specific treatment.

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Evaluation of Bead-Based Assays for the Isolation of Foodborne Viruses from Low-Moisture Foods

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-345 ◽

2020 ◽

Vol 83 (3) ◽

pp. 388-396 ◽

Cited By ~ 2

Author(s):

NEDA NASHERI ◽

JENNIFER HARLOW ◽

ANGELA CHEN ◽

NATHALIE CORNEAU ◽

SABAH BIDAWID

Keyword(s):

Magnetic Beads ◽

Hepatitis A Virus ◽

Virus Transmission ◽

Magnetic Bead ◽

Murine Norovirus ◽

Foodborne Viruses ◽

Recovery Rates ◽

Porcine Gastric Mucin ◽

Low Moisture Foods ◽

Virus Recovery

ABSTRACT Foodborne viruses such as norovirus and hepatitis A virus (HAV) are highly transmissible, persistent in the environment, and resistant to many conventional inactivation methods. Foods can become contaminated with these viruses either at the source of harvest or during food handling and processing. Multiple lines of evidence suggest that foodborne viruses can survive desiccation and dry conditions. Several foodborne virus outbreaks have been linked to low-moisture foods (LMFs), indicating that these foods can be vehicles of virus transmission. However, the efficiencies of common virus extraction methodologies have not been examined with LMFs. We adapted the International Organization for Standardization (ISO) 15216-1:2017 method for virus recovery for use with chocolate, pistachios, and cornflakes. We also developed a magnetic bead assay for the recovery of HAV from LMFs and used the porcine gastric mucin–coated magnetic beads (PGM-MBs) to extract norovirus surrogates, feline calicivirus (FCV), and murine norovirus (MNV) from the same LMFs. The efficiency of virus recovery using the bead-based assay was then compared with that of the ISO 15216-1:2017 method. In chocolate and pistachios, the recovery rates with the PGM-MB method were 5.6- and 21.3-fold higher, respectively, for FCV and 1.65- and 18-fold higher, respectively, for MNV than those with the ISO 15216-1:2017 method. However, the PGM-MB method failed to recover MNV and FCV from cornflakes. The recovery rates for HAV in chocolate, pistachios, and corn flakes with the magnetic bead method were 11.5-, 3-, and 5.6-fold higher, respectively, than those with the ISO 15216-1:2017 method. Thus, depending upon the food matrix and the target virus, the bead-based assays can be used to efficiently and rapidly extract viruses from LMFs. HIGHLIGHTS

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Development of an RNA Extraction Protocol for a Norovirus from Raw Oysters and Detection by qRT-PCR and Droplet-Digital RT-PCR

Foods ◽

10.3390/foods10081804 ◽

2021 ◽

Vol 10 (8) ◽

pp. 1804

Author(s):

Daniel Plante ◽

Julio Alexander Bran Barrera ◽

Maude Lord ◽

Irène Iugovaz ◽

Neda Nasheri

Keyword(s):

Hepatitis A Virus ◽

Rna Extraction ◽

Complex Nature ◽

Murine Norovirus ◽

Rt Pcr ◽

Pcr Inhibitors ◽

Qrt Pcr ◽

Extraction Protocol ◽

Viral Particles ◽

Hands On

Foodborne viruses such as norovirus and hepatitis A virus cause frequent outbreaks associated with the consumption of raw or undercooked oysters. Viral particles are bioaccumulated in the oyster’s digestive glands, making RNA extraction and RT-PCR detection difficult due to the complex nature of the food matrix and the presence of RT-PCR inhibitors. Herein, we have developed a viral RNA extraction protocol from raw oysters using murine norovirus (MNV) as a surrogate for human noroviruses. The method combines lysis in Tri-Reagent reagent, followed by RNA extraction using Direct-Zol purification columns and lithium chloride precipitation. Viral load quantification was performed by both qRT-PCR and droplet-digital RT-PCR. We have demonstrated that this method can efficiently remove RT-PCR inhibitors, and is sensitive enough to reliably detect viral contamination at 25 PFU/0.2 g. We have also compared the efficiency of this method with the ISO 15216-1:2017 method and Method E developed by Quang and colleagues, and observed significantly higher efficiency compared with the ISO 15216-1 method and comparable efficiency with Method E, with less steps, and shorter hands-on time.

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