Survival of Hepatitis A Virus on Two-month Stored Freeze-dried Berries

2021 ◽  
Author(s):  
Yan Zhang ◽  
Xueyan Wang ◽  
Y. Carol Shieh
Keyword(s):  
Freeze Drying ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Reduction Rate ◽  
Radiant Heating ◽  
Minimal Processing ◽  
Log Reduction ◽  
C Storage ◽  
Freeze Dried ◽  
Heating Up

Imported berries have contributed to U.S. hepatitis A virus (HAV) infections. Minimal processing by freeze-drying is preferred by industry for preserving food quality, but virus inactivation by this process may be limited. This study investigated HAV survival on strawberries during 24-h freeze-drying followed by 22 ° C-storage. The outer surfaces of strawberry slices were prepared and each inoculated with 5 to 6 log 10 PFU HAV, air-dried 20 min, frozen 1 h at -80 °C, and freeze-dried 24 h with radiant heating up to 36 °C. Infectious HAV levels eluted from berry slices were quantified on FRhK-4 cells grown onto 6-well dishes. Freeze-drying trials (n = 17) with radiant heating inactivated ≤1 log 10 PFU per trial, although HAV-inactivation was significantly greater at 36 ºC than 15 ºC heating ( p < 0.01). Average HAV reduction rate on dried berries continuously decreased as storage time increased, 0.2, 0.09, 0.08, 0.04, 0.04 and 0.03 log-reduction/day at day 2, 7, 14, 28, 42, and 56, respectively, with the cumulated log-reduction divided by storage days. Therefore, the best fit regression for the total/cumulative virus reduction (Y) at any given day (X) is Y= 0.2882X 0.4503 (r² = 0.97), with maximum 2.7 log-reduction on berries throughout the drying and subsequent 2-month storage. HAV showed the greatest decline within the first 14-days of storage of dried berries (approximately 70% weekly reduction from its previous week levels), but the HAV reduction rates were still lower than that occurring on fresh produce.

scholarly journals Chlorine inactivation of coliphage MS2 on strawberries by industrial-scale water washing units

2009 ◽  
Vol 7 (2) ◽  
pp. 244-250 ◽  
Author(s):  
Michael J. Casteel ◽  
Charles E. Schmidt ◽  
Mark D. Sobsey
Keyword(s):  
Hepatitis A ◽  
Fruits And Vegetables ◽  
Hepatitis A Virus ◽  
Field Studies ◽  
Wash Water ◽  
Industrial Scale ◽  
Cross Contamination ◽  
Minimal Processing ◽  
Water Washing ◽  
Pathogenic Viruses

Fruits and vegetables (produce) intended for minimal processing are often rinsed or washed in water. Chlorine and other sanitizers are used during washing to inactivate produce spoilage microbes, but such procedures may also inactivate pathogens epidemiologically linked to produce, such as hepatitis A virus (HAV). However, no information exists on the efficacy of chlorinated wash water to inactivate HAV and other viruses on produce in actual practice, because of obvious safety concerns. In contrast, coliphage MS2 (a bacterial virus) is commonly used as a surrogate for some pathogenic viruses and may be safely used in field studies. In the present investigation, strawberries seeded with MS2 were passed through industrial-scale water washing units operated with or without added sodium hypochlorite. MS2 on strawberries was inactivated by 68%, 92% and 96% at free chlorine (FC) concentrations of ≤2, 20 and 200 ppm in wash water, respectively. MS2 was detected in wash water containing ≤2 ppm FC in one trial, but was not detected in water containing 20 or 200 ppm FC. The presence and absence of MS2 in wash water containing various levels of FC highlight the importance of controlling sanitizer levels to prevent viral cross contamination of strawberries.

Survival and Persistence of Norovirus, Hepatitis A Virus, and Feline Calicivirus in Marinated Mussels

2004 ◽  
Vol 67 (8) ◽  
pp. 1743-1750 ◽  
Author(s):  
JOANNE HEWITT ◽  
GAIL E. GREENING
Keyword(s):  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Enteric Viruses ◽  
Feline Calicivirus ◽  
Rt Pcr ◽  
Pcr Assay ◽  
Potential Health ◽  
Infectious Dose ◽  
Log Reduction ◽  
Public Health Authorities

Noroviruses (NV) and hepatitis A virus (HAV) are foodborne enteric viruses associated with outbreaks of disease following consumption of raw or lightly cooked bivalve shellfish. Marinated mussels are a popular delicacy, but there is no published information on whether enteric viruses survive the marination process. The survival and persistence of HAV, NV, and a surrogate calicivirus, feline calicivirus (FCV), in marinated mussels over time was determined. NV, HAV, and FCV were inoculated into marinated mussels and marinade liquid and then held at 4°C for up to 4 weeks. Survival of HAV and FCV was quantified by determining the 50% tissue culture infectious dose (TCID50), and these results were correlated with those of the reverse transcription (RT)–PCR assay. The persistence of nonculturable NV was determined by RT–PCR assay only. Over 4 weeks, HAV survived exposure to acid marinade at pH 3.75. There was a 1.7-log reduction in HAV TCID50 titer but no reduction in NV or HAV RT-PCR titer after 4 weeks in marinated mussels. FCV was inactivated in acid conditions although it was still detectable by RT-PCR. To simulate preharvest virus contamination and commercial marination processing, experiments using fresh mussels infected with HAV and NV were performed. HAV and NV persistence was determined using semiquantitative real-time RT-PCR, and HAV infectivity was determined by the TCID50 assay. HAV retained infectivity following simulated commercial marination and exposure to acid conditions over 4 weeks. The survival of pathogenic enteric viruses in marinated mussels constitutes a potential health risk and so is of concern to public health authorities.

scholarly journals Inactivation of Enteric Viruses in Minimally Processed Berries and Herbs

2009 ◽  
Vol 75 (12) ◽  
pp. 4155-4161 ◽  
Author(s):  
S. Butot ◽  
T. Putallaz ◽  
R. Amoroso ◽  
G. Sánchez
Keyword(s):  
Freeze Drying ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Raw Materials ◽  
Enteric Viruses ◽  
Rt Pcr ◽  
Processing Technologies ◽  
Viral Contamination ◽  
Reverse Transcription Pcr ◽  
Dry Heat Treatment

ABSTRACT Several hepatitis A virus (HAV) and human norovirus (HuNoV) outbreaks due to consumption of contaminated berries and vegetables have recently been reported. Model experiments were performed to determine the effectiveness of freeze-drying, freeze-drying combined with heating, and steam blanching for inactivation of enteric viruses that might be present on the surface of berries and herbs. Inactivation of HAV and inactivation of feline calicivirus, a surrogate for HuNoV, were assessed by viral culturing and quantitative reverse transcription PCR (RT-PCR), whereas HuNoV survival was determined only by quantitative RT-PCR. While freeze-drying barely reduced (<1.3 log10 units) the amount of HAV RNA detected in frozen produce, a greater decline in HAV infectivity was observed. The resistance of HuNoV genogroup I (GI) to freeze-drying was significantly higher than that of HuNoV GII on berries. Addition of a terminal dry heat treatment at 120°C after freeze-drying enhanced virus inactivation by at least 2 log10 units, except for HuNoV GII. The results suggest that steam blanching at 95°C for 2.5 min effectively inactivated infectious enteric viruses if they were present in herbs. Our results provide data for adjusting food processing technologies if viral contamination of raw materials is suspected.

Heat Inactivation of Hepatitis A Virus in Dairy Foods†

2000 ◽  
Vol 63 (4) ◽  
pp. 522-528 ◽  
Author(s):  
S. BIDAWID ◽  
J. M. FARBER ◽  
S. A. SATTAR ◽  
S. HAYWARD
Keyword(s):  
Dairy Products ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Plaque Assay ◽  
Virus Titer ◽  
Skim Milk ◽  
Fat Content ◽  
Heat Inactivation ◽  
Log Reduction ◽  
Custom Made

Experiments were performed to determine the thermal resistance of hepatitis A virus (HAV) in three types of dairy products containing increased amounts of fat content (skim milk, homogenized milk; 3.5% MFG, and table cream; 18% MFG). HAV-inoculated dairy products were introduced into custom-made U-shaped microcapillary tubes that in turn were simultaneously immersed in a waterbath, using custom-made floating boats and a carrying platform. Following exposure to the desired time and temperature combinations, the contents of each of the tubes was retrieved and was tested by plaque assay to determine the reduction in virus titer. Our data indicated that &lt;0.5 min at 85°C was sufficient to cause a 5-log reduction in HAV titer in all three dairy products, whereas at 80°C, ≤0.68 min (for skim and homogenized milk), and 1.24 min (for cream) were needed to cause a similar log reduction. Using a nonlinear two-phase negative exponential model (two-compartment model) to analyze the data, it was found that at temperatures of 65, 67, 69, 71, and 75°C, significantly (P &lt; 0.05) higher exposure times were needed to achieve a 1-log reduction in virus titer in cream, as compared to skim and homogenized milk. For example, at 71°C, a significantly (P &lt; 0.05) higher exposure time of 0.52 min (for cream) was needed as compared to ≤0.18 min (for skim and homogenized milk) to achieve a 1-log reduction in virus titer. A similar trend of inactivation was observed at 73 and 75°C where significantly (P &lt; 0.05) higher exposure times of 0.29 to 0.36 min for cream were needed to cause a 1-log reduction in HAV in cream, as compared to ≤0.17 min for skim and homogenized milk. This study has provided information on the heat resistance of HAV in skim milk, homogenized milk, and table cream and demonstrated that an increase in fat content appears to play a protective role and contributes to the heat stability of HAV.

Disinfection of Hepatitis a Virus and MS-2 Coliphage in Water by Ultraviolet Irradiation: Comparison of UV-Susceptibility

1993 ◽  
Vol 27 (3-4) ◽  
pp. 335-338 ◽  
Author(s):  
A. Wiedenmann ◽  
B. Fischer ◽  
U. Straub ◽  
C.-H. Wang ◽  
B. Flehmig ◽  
...  
Keyword(s):  
Water Treatment ◽  
Ultraviolet Irradiation ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Waste Water Treatment ◽  
Reduction Rate ◽  
Treatment Processes ◽  
Quality Of Water ◽  
Disinfection Procedure ◽  
Uv Dose

Ultraviolet irradiation is gaining importance as a disinfection procedure for drinking water and in waste water treatment. Since water is one of the main transmission routes of hepatitis A virus the susceptibility of HAV to UV rays is of special interest. MS-2 coliphage resembles HAV in size and structure, is easy to handle, and might tlierefore serve as indicator organism for the assessment of water quality and for evaluating the quality of water treatment processes. Hepatitis A virus and MS-2 coliphage were suspended in 0.9% sodium chloride solution and were irradiated in a 20-ml quarz cuvette at 254 nm. For a reduction rate of four log units a three times liigher UV dose was required with MS-2 than with HAV.

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

2016 ◽  
Vol 79 (9) ◽  
pp. 1517-1526 ◽  
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 (&lt;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 &gt;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.

scholarly journals Inactivation of Hepatitis A Virus and Human Norovirus in Clams Subjected to Heat Treatment

2021 ◽  
Vol 11 ◽  
Author(s):  
Cristina Fuentes ◽  
Francisco J. Pérez-Rodríguez ◽  
Aurora Sabrià ◽  
Nerea Beguiristain ◽  
Rosa M. Pintó ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Food Product ◽  
Performance Criterion ◽  
Performance Criteria ◽  
Economic Implications ◽  
Log Reduction ◽  
A Cell ◽  
A Performance

Bivalve mollusk contamination by enteric viruses, especially human noroviruses (HuNoV) and hepatitis A virus (HAV), is a problem with health and economic implications. The aim of the study was the evaluation of the effect of heat treatment in clams (Tawera gayi) experimentally contaminated with HuNoV using a PMA-viability RTqPCR assay to minimize measurement of non-infectious viruses, and used HAV as a model to estimate infectivity loss. Spiked clams were immersed in water at 90°C to ensure that internal meat temperature was maintained above 90°C for at least 5 min. The treatment resulted in &gt;3.89 ± 0.24 log10 TCID50/g reduction of infectious HAV, confirming inactivation. For HuNoV, RTqPCR assays showed log10 reductions of 2.96 ± 0.79 and 2.56 ± 0.56, for GI and GII, respectively, and the use of PMA resulted in an additional log10 reduction for GII, providing a better correlation with risk reduction. In the absence of a cell culture system which could be used to determine HuNoV infectivity reduction, a performance criteria based on PMA-RTqPCR log reduction could be used to evaluate food product safety. According to data from this study, heat treatments of clams which cause reductions &gt;3.5 log10 for GII as measured by PMA-RTqPCR assay may be regarded as an acceptable inactivation treatment, and could be set as a performance criterion to test the effectiveness of other time-temperature inactivation processes.

scholarly journals Freeze-Drying of Plant-Based Foods

Foods ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 87 ◽  
Author(s):  
Sagar Bhatta ◽  
Tatjana Stevanovic Janezic ◽  
Cristina Ratti
Keyword(s):  
Freeze Drying ◽  
Fruits And Vegetables ◽  
Space Shuttle ◽  
Bioactive Compound ◽  
Biological Materials ◽  
Plasma Vitamin ◽  
Minimal Processing ◽  
Maple Syrup ◽  
Freeze Dried ◽  
Wide Range

Vacuum freeze-drying of biological materials is one of the best methods of water removal, with final products of highest quality. The solid state of water during freeze-drying protects the primary structure and the shape of the products with minimal volume reduction. In addition, the lower temperatures in the process allow maximal nutrient and bioactive compound retention. This technique has been successfully applied to diverse biological materials, such as meats, coffee, juices, dairy products, cells, and bacteria, and is standard practice for penicillin, hormones, blood plasma, vitamin preparations, etc. Despite its many advantages, having four to ten times more energy requirements than regular hot air drying, freeze-drying has always been recognized as the most expensive process for manufacturing a dehydrated product. The application of the freeze-drying process to plant-based foods has been traditionally dedicated to the production of space shuttle goods, military or extreme-sport foodstuffs, and specialty foods such as coffee or spices. Recently, the market for ‘natural’ and ‘organic’ products is, however, strongly growing as well as the consumer’s demand for foods with minimal processing and high quality. From this perspective, the market for freeze-dried plant-based foods is not only increasing but also diversifying. Freeze-dried fruits and vegetables chunks, pieces, or slices are nowadays majorly used in a wide range of food products such as confectionaries, morning cereals, soups, bakeries, meal boxes, etc. Instant drinks are prepared out of freeze-dried tea, coffee, or even from maple syrup enriched with polyphenol concentrated extracts from trees. The possibilities are endless. In this review, the application of freeze-drying to transform plant-based foods was analyzed, based on the recent research publications on the subject and personal unpublished data. The review is structured around the following related topics: latest applications of freeze-drying to plant-based foods, specific technological problems that could be found when freeze-drying such products (i.e., presence of cuticle; high sugar or lipid concentration), pretreatments and intensification technologies employed in freeze-drying of plant-based foods, and quality issues of these freeze-dried products.

Scanning Electron Microscopy-cuticular Lesions on the Roundworm Ascaris Suum

1970 ◽  
Vol 28 ◽  
pp. 114-115
Author(s):  
P. A. Madden ◽  
W. R. Anderson
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Freeze Drying ◽  
Room Temperature ◽  
Secondary Electron ◽  
Distilled Water ◽  
Freeze Dried ◽  
Silver Paint ◽  
To Come ◽  
Scanning Electron

The intestinal roundworm of swine is pinkish in color and about the diameter of a lead pencil. Adult worms, taken from parasitized swine, frequently were observed with macroscopic lesions on their cuticule. Those possessing such lesions were rinsed in distilled water, and cylindrical segments of the affected areas were removed. Some of the segments were fixed in buffered formalin before freeze-drying; others were freeze-dried immediately. Initially, specimens were quenched in liquid freon followed by immersion in liquid nitrogen. They were then placed in ampuoles in a freezer at −45C and sublimated by vacuum until dry. After the specimens appeared dry, the freezer was allowed to come to room temperature slowly while the vacuum was maintained. The dried specimens were attached to metal pegs with conductive silver paint and placed in a vacuum evaporator on a rotating tilting stage. They were then coated by evaporating an alloy of 20% palladium and 80% gold to a thickness of approximately 300 A°. The specimens were examined by secondary electron emmission in a scanning electron microscope.

Application of solid-phase immune electron microscopy to study physical and stability characteristics of enterically transmitted non-a, non-b hepatitis virus

1988 ◽  
Vol 46 ◽  
pp. 80-81
Author(s):  
Charles D. Humphrey ◽  
E. H. Cook ◽  
Karen A. McCaustland ◽  
Daniel W. Bradley
Keyword(s):  
Electron Microscopy ◽  
Hepatitis A ◽  
Hepatitis A Virus ◽  
Solid Phase ◽  
Etiologic Agent ◽  
World Health ◽  
Health Concern ◽  
Morphological Identification ◽  
Immune Electron Microscopy

Enterically transmitted non-A, non-B hepatitis (ET-NANBH) is a type of hepatitis which is increasingly becoming a significant world health concern. As with hepatitis A virus (HAV), spread is by the fecal-oral mode of transmission. Until recently, the etiologic agent had not been isolated and identified. We have succeeded in the isolation and preliminary characterization of this virus and demonstrating that this agent can cause hepatic disease and seroconversion in experimental primates. Our characterization of this virus was facilitated by immune (IEM) and solid phase immune electron microscopic (SPIEM) methodologies.Many immune electron microscopy methodologies have been used for morphological identification and characterization of viruses. We have previously reported a highly effective solid phase immune electron microscopy procedure which facilitated identification of hepatitis A virus (HAV) in crude cell culture extracts. More recently we have reported utilization of the method for identification of an etiologic agent responsible for (ET-NANBH).

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