scholarly journals Efficient Reduction of Food Related Mould Spores on Surfaces by Hydrogen Peroxide Mist

Foods ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 55
Author(s):  
Cathrine Finne Kure ◽  
Solveig Langsrud ◽  
Trond Møretrø
Keyword(s):  
Skim Milk ◽  
Geotrichum Candidum ◽  
Paecilomyces Variotii ◽  
Log Reduction ◽  
Fungicidal Effect ◽  
Meat Juice ◽  
Efficient Reduction ◽  
Surface Test ◽  
Penicillium Solitum ◽  
Generating System

The aim of the study was to evaluate the fungicidal effect of a H2O2 mist generating system for disinfection of spores of six food-related moulds (Alternaria alternata, Aspergillus flavus, Geotrichum candidum, Mucor plumbeus, Paecilomyces variotii, and Penicillium solitum) dried on stainless steel. Exposure to H2O2 mist for 2 or 4 h lead to >3 log reduction in mould spores in the majority of the tests. The presence of the soils 2% skim milk or 3% BSA did not significantly alter the fungicidal effect, while the presence of raw meat juice had an adverse fungicidal effect against Penicillium and Mucor in two out of three tests. Fungicidal suspension tests with liquid H2O2 confirmed the effectiveness of H2O2 on reducing the mould spores. Both the surface test and the suspension test indicated that P. variotii is more resistant to H2O2 compared to the other moulds tested. The study shows the efficiency of H2O2 mist on reducing food-related mould spores on surfaces.

Inactivation of Yersinia pseudotuberculosis 197 and Francisella tularensis LVS in Beverages by High Pressure Processing

2009 ◽  
Vol 72 (1) ◽  
pp. 165-168 ◽  
Author(s):  
JOSEPH E. SCHLESSER ◽  
BRIAN PARISI
Keyword(s):  
High Pressure ◽  
Francisella Tularensis ◽  
Orange Juice ◽  
Yersinia Pseudotuberculosis ◽  
Hold Time ◽  
Skim Milk ◽  
High Pressure Processing ◽  
Pressure Treatment ◽  
Log Reduction ◽  
Pressure Resistance

In 2003, the U.S. Department of Health and Human Services announced a new research program to develop technologies and strategies to prevent and minimize potential food safety and security threats. The threat of terrorist attacks against the nation's food supplies has created the need to study microorganisms not typically associated with foodborne illness. High-pressure processing has been proposed as a treatment to reduce Yersinia pestis and Francisella tularensis LVS levels in beverages. The objectives of this work were to determine the pressure resistance of Y. pseudotuberculosis 197 (surrogate for Y. pestis) and F. tularensis LVS (vaccine strain). For each bacterium, samples of ultrahigh-temperature pasteurized skim milk and pasteurized reduced-acid orange juice (pH ca. 4.2) were inoculated at a minimum level of 5 log CFU/ml. Ten-milliliter samples of the inoculated product were vacuum sealed in polyester pouches and subjected to pressures of 300 and 500 MPa for holding times ranging from 30 s to 6 min. One set of trials was performed at an initial temperature of 10°C and another at 25°C. Processed samples were immediately plated and enumerated. A pressure treatment of 300 MPa at 25°C for less than 6 min was not sufficient to achieve a 5-log reduction of Y. pseudotuberculosis 197 or F. tularensis LVS in milk. However, a pressure treatment of 500 MPa was effective at hold times as low as 30 s. Overall, F. tularensis LVS demonstrated less pressure resistance than Y. pseudotuberculosis 197. Based on these findings, a high-pressure process designed to inactivate 5 log CFU of Y. pseudotuberculosis 197 per ml and F. tularensis LVS in orange juice or milk should be set at or above 500 MPa with a hold time of 2 min or greater.

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 <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 < 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 < 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 < 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.

Inactivation of Lactobacillus Virulent Bacteriophage by Thermal and Chemical Treatments

2018 ◽  
Vol 81 (10) ◽  
pp. 1673-1678 ◽  
Author(s):  
XIA CHEN ◽  
YING LIU ◽  
SHIYU CHAI ◽  
JING GUO ◽  
WENRU WU
Keyword(s):  
Sodium Hypochlorite ◽  
Peracetic Acid ◽  
Additional Data ◽  
Skim Milk ◽  
Thermal Treatments ◽  
Log Reduction ◽  
Chemical Treatments ◽  
Bacteriophage P2 ◽  
De Man ◽  
Minimum Heat

ABSTRACT The uses of thermal and chemical treatments were evaluated with respect to the inactivation of the Lactobacillus virulent bacteriophage P2. Thermal treatments consisted of heating the phage at 63, 72, and 90°C in three broth media: de Man Rogosa Sharpe broth, reconstituted skim milk, and Tris magnesium gelatin buffer. Chemical treatments evaluated were ethanol, isopropanol, sodium hypochlorite, and peracetic acid at various concentrations. Phage P2 was completely inactivated in 20 and 5 min at 72 and 90°C, respectively. Reconstituted skim milk and de Man Rogosa Sharpe broth provided optimum and minimum heat protection, respectively. Only sodium hypochlorite at 400 and 800 ppm completely inactivated the phage in 50 and 30 min, respectively. Treatment with 100% ethanol and isopropanol resulted in only a ca. 5.1-log reduction. Peracetic acid at the highest concentration used (0.45%) resulted in only a 1.40-log reduction of the phage within 60 min. These results provide additional data for establishing effective methods of controlling phage contamination in dairy and laboratory environments.

Cytotoxic Effect of Pseudomonas aurogenosa Protease on Cancer Cells

2019 ◽  
Vol 10 (03) ◽  
Author(s):  
Ghanyia J. Shanyoor ◽  
Fatima R. Abdul ◽  
Nehad A. Taher ◽  
Ihsan A. Raheem
Keyword(s):  
Cell Line ◽  
Normal Cell ◽  
Cytotoxic Effect ◽  
Human Cancer ◽  
Skim Milk ◽  
Exchange Chromatography ◽  
Protease Production ◽  
Normal Cell Line ◽  
Protease Enzyme ◽  
Embryonic Fibroblast

About (20) Pseudomonas rogenosa isolate were experienced for their ability of protease production by calculating the diameter of lysis area after developing on skim milk agar medium (qualitatively ) and the results exhibited that only isolate no (5), was higher isolate for protease making of (26mm) of lysis area. Then, the protein concentration also identified by Bradford method and it was found of 0.16 mg/ ml , then purification was done by using an ion- exchange chromatography with DEAE sephadex G- 100 column and the results showed the presence of 1 peak of enzyme with 50 Kd of molecular weight 2 peaks of other proteins . we tried to investigate the invitro Cytotoxic effect of purified enzyme against two human cancer lines, HeP2 (Human larynx epidermed carcinoma ) , RD ( Rabdo- Sarcoma ) , and one normal cell line Ref ( Rat embryonic fibroblast ) . The cancer and normal cells were treated with different concentrations of protease enzyme ranging from ( 0.05, 0.1, 0.2, 0.4,0.8and 0.16 mg/ml) then incubated for additional 48h at 37C0 and the results showed highest toxicity ( 80.28%) of protease enzyme on RD , moderate cytotoxicity (45.52%) on Hep andslight toxicity ( 37.12% ) on normal cell line (Ref) in a concentration (0.8mg/ml).

Optimization of pectinase production from Geotrichum candidum AA15 using response surface methodology

2018 ◽  
Vol 51 (2) ◽  
Author(s):  
Asia Ahmed ◽  
Muhammad Naseem Khan ◽  
Aqeel Ahmad ◽  
Shakeel Ahmed Khan ◽  
Muhammad Sohail
Keyword(s):  
Response Surface Methodology ◽  
Response Surface ◽  
Geotrichum Candidum ◽  
Pectinase Production

Effect of the electro-dialysis treatment temperature on the microflora of skim milk permeate

2018 ◽  
pp. 14-15
Author(s):  
Anisimov G.S. ◽  
◽  
Evdokimov I.A. ◽  
Ryabtseva S.A. ◽  
Donskih A.N. ◽  
...  
Keyword(s):  
Skim Milk ◽  
Treatment Temperature ◽  
Dialysis Treatment ◽  
Milk Permeate
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