The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Tim Hogg - One of the best experts on this subject based on the ideXlab platform.
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Thermal Inactivation of the wine spoilage yeasts dekkera brettanomyces
International Journal of Food Microbiology, 2005Co-Authors: José António Couto, Filipe Neves, Francisco M. Campos, Tim HoggAbstract:The heat resistance of three strains of Dekkera/Brettanomyces (Dekkera anomala PYCC 5,153, Dekkera bruxellensis PYCC 4,801 and Dekkera/Brettanomyces 093) was evaluated at different temperatures between 32.5 and 55 degrees C. Thermal Inactivation tests were performed in tartrate buffer solution (pH 4.0) and in wines. In the studies employing buffer as the heating menstruum, measurable Thermal Inactivation began only at temperatures of 50 degrees C. When heating was performed in wine, significant Inactivation begins at 35 degrees C. Subsequent Thermal Inactivation tests were performed in buffer at various levels of pH, ethanol concentration, and various phenolic acids. Results from experiments in buffer with added ethanol suggest that the greater heat sensitivity shown in wines can be largely attributed to ethanol, although potentiation of this effect might be due to the phenolic content, particularly from ferulic acid. In the range of pH values tested (2.5-4.5), this factor had no influence in the heat Inactivation kinetics. Relevant data, in the form of D and Z values calculated in the various environments, potentially useful for the establishment of regimes of Thermal control of Dekkera/Brettanomyces yeasts in wine and contaminated equipment is presented.
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Thermal Inactivation of the wine spoilage yeasts Dekkera/Brettanomyces.
International journal of food microbiology, 2005Co-Authors: José António Couto, Filipe Neves, Francisco M. Campos, Tim HoggAbstract:Abstract The heat resistance of three strains of Dekkera/Brettanomyces ( Dekkera anomala PYCC 5153, Dekkera bruxellensis PYCC 4801 and Dekkera/Brettanomyces 093) was evaluated at different temperatures between 32.5 and 55 °C. Thermal Inactivation tests were performed in tartrate buffer solution (pH 4.0) and in wines. In the studies employing buffer as the heating menstruum, measurable Thermal Inactivation began only at temperatures of 50 °C. When heating was performed in wine, significant Inactivation begins at 35 °C. Subsequent Thermal Inactivation tests were performed in buffer at various levels of pH, ethanol concentration, and various phenolic acids. Results from experiments in buffer with added ethanol suggest that the greater heat sensitivity shown in wines can be largely attributed to ethanol, although potentiation of this effect might be due to the phenolic content, particularly from ferulic acid. In the range of pH values tested (2.5–4.5), this factor had no influence in the heat Inactivation kinetics. Relevant data, in the form of D and Z values calculated in the various environments, potentially useful for the establishment of regimes of Thermal control of Dekkera/Brettanomyces yeasts in wine and contaminated equipment is presented.
Takeshi Itoh - One of the best experts on this subject based on the ideXlab platform.
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Thermal Inactivation analysis of mesophiles using the Arrhenius and z-value models.
Journal of Food Protection, 1998Co-Authors: Hiroshi Fujikawa, Takeshi ItohAbstract:The Arrhenius and z-value models were compared for Thermal Inactivation analysis of a mesophilic bacterium. The models produced a linear curve for the Thermal Inactivation data. Concerning the rate constant of Inactivation, the D and k values predicted by the models at a constant temperature were similar. For extrapolated temperatures the z-value model predicted an insignificant decrease in the survival ratio compared to the Arrhenius model. The dynamic temperature survival curves predicted by the models were similar, and the models characterized the results. These results demonstrated that the models can be used for Thermal Inactivation analysis of mesophiles at various temperatures.
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Tailing of Thermal Inactivation curve of Aspergillus niger spores.
Applied and environmental microbiology, 1996Co-Authors: Hiroshi Fujikawa, Takeshi ItohAbstract:The nonlinear Thermal Inactivation of Aspergillus niger spores in phosphate-citrate buffer was studied. The Thermal Inactivation pattern of the spore consisted of a shoulder, an accelerated decline, and a tail at various constant temperatures around 60 degrees C. The pattern fitted a thermotolerant subpopulation model. In the model, we postulated that some spores in the initial population had become thermotolerant at a certain ratio during heating. The model parameters including the rate coefficients, the time lag, and the existence ratio of thermotolerant cells were analyzed at various temperatures. The tailing was not observed at an initial concentration below 10(3) cells per ml. Cells cultured from thermotolerant cells showed an Inactivation pattern similar to that of the original cells. Also, cells at the second heating showed the same thermotolerance as or were slightly more thermosensitive than the original cells. Intermittent heating was found to be effective to inactivate cells at a high concentration.
Filipe Neves - One of the best experts on this subject based on the ideXlab platform.
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Thermal Inactivation of the wine spoilage yeasts dekkera brettanomyces
International Journal of Food Microbiology, 2005Co-Authors: José António Couto, Filipe Neves, Francisco M. Campos, Tim HoggAbstract:The heat resistance of three strains of Dekkera/Brettanomyces (Dekkera anomala PYCC 5,153, Dekkera bruxellensis PYCC 4,801 and Dekkera/Brettanomyces 093) was evaluated at different temperatures between 32.5 and 55 degrees C. Thermal Inactivation tests were performed in tartrate buffer solution (pH 4.0) and in wines. In the studies employing buffer as the heating menstruum, measurable Thermal Inactivation began only at temperatures of 50 degrees C. When heating was performed in wine, significant Inactivation begins at 35 degrees C. Subsequent Thermal Inactivation tests were performed in buffer at various levels of pH, ethanol concentration, and various phenolic acids. Results from experiments in buffer with added ethanol suggest that the greater heat sensitivity shown in wines can be largely attributed to ethanol, although potentiation of this effect might be due to the phenolic content, particularly from ferulic acid. In the range of pH values tested (2.5-4.5), this factor had no influence in the heat Inactivation kinetics. Relevant data, in the form of D and Z values calculated in the various environments, potentially useful for the establishment of regimes of Thermal control of Dekkera/Brettanomyces yeasts in wine and contaminated equipment is presented.
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Thermal Inactivation of the wine spoilage yeasts Dekkera/Brettanomyces.
International journal of food microbiology, 2005Co-Authors: José António Couto, Filipe Neves, Francisco M. Campos, Tim HoggAbstract:Abstract The heat resistance of three strains of Dekkera/Brettanomyces ( Dekkera anomala PYCC 5153, Dekkera bruxellensis PYCC 4801 and Dekkera/Brettanomyces 093) was evaluated at different temperatures between 32.5 and 55 °C. Thermal Inactivation tests were performed in tartrate buffer solution (pH 4.0) and in wines. In the studies employing buffer as the heating menstruum, measurable Thermal Inactivation began only at temperatures of 50 °C. When heating was performed in wine, significant Inactivation begins at 35 °C. Subsequent Thermal Inactivation tests were performed in buffer at various levels of pH, ethanol concentration, and various phenolic acids. Results from experiments in buffer with added ethanol suggest that the greater heat sensitivity shown in wines can be largely attributed to ethanol, although potentiation of this effect might be due to the phenolic content, particularly from ferulic acid. In the range of pH values tested (2.5–4.5), this factor had no influence in the heat Inactivation kinetics. Relevant data, in the form of D and Z values calculated in the various environments, potentially useful for the establishment of regimes of Thermal control of Dekkera/Brettanomyces yeasts in wine and contaminated equipment is presented.
Alicia Orta-ramirez - One of the best experts on this subject based on the ideXlab platform.
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Effect of water activity on Thermal Inactivation of salmonella in ground Turkey
Journal of Food Science, 2005Co-Authors: Tausha R. Carlson, Bradley P. Marks, Alden M. Booren, Elliot T. Ryser, Alicia Orta-ramirezAbstract:Many factors, such as fat content and pH, are known to affect Thermal Inactivation of pathogens in meat products, and a few studies have suggested that the humidity of the cooking environment also affects Thermal Inactivation. However, the effect of process humidity has not been previously isolated from the effect of water activity on Salmonella Inactivation. Therefore, the objective of this study was to directly test the effect of meat water activity on Thermal Inactivation of Salmonella. Ground turkey was dried to achieve water activities of 0.95 to 0.99, inoculated with an 8-strain Salmonella cocktail, and heated isoThermally (60 °C) in a water bath. The rate of Thermal Inactivation of Salmonella decreased 64% (P < 0.01) when decreasing meat water activity from 0.99 to 0.95. Inclusion of water activity improved the accuracy of a 1st-order/Arrhenius-type Inactivation model from 1.94 log 10 to 0.8 log 10 (colony-forming units [CFU] /g).
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Thermal Inactivation of pathogens and verification of adequate cooking in meat and poultry products.
Advances in food and nutrition research, 2002Co-Authors: Alicia Orta-ramirez, Denise M. SmithAbstract:Publisher Summary This chapter discusses Thermal Inactivation of pathogens and verification of adequate cooking in meat and poultry products. The chapter reviews Thermal processing as a means to eliminate microbial pathogens in meat and poultry. Besides discussing the evolution of Thermal processing regulations in the US and listing official and alternative tests to verify compliance with the cooking requirements, an effort has been made to evaluate the advantages and disadvantages for each of the verification methods as well as the challenges to determine the Thermal Inactivation kinetics of microbial pathogens. The chapter reviews the Thermal processing requirements currently implemented in the US; Thermal Inactivation of most common microbial pathogens found in meat and poultry products, and the use of thermometers, color determination, endpoint temperature indicators, and time-temperature integrators as means of verifying Thermal processing adequacy.
Hayriye Bozkurt - One of the best experts on this subject based on the ideXlab platform.
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Thermal Inactivation kinetics of hepatitis a virus in homogenized clam meat mercenaria mercenaria
Journal of Applied Microbiology, 2015Co-Authors: Hayriye Bozkurt, Doris H Dsouza, P M DavidsonAbstract:Aims Epidemiological evidence suggests that hepatitis A virus (HAV) is the most common pathogen transmitted by bivalve molluscs such as clams, cockles, mussels and oysters. This study aimed to generate Thermal Inactivation kinetics for HAV as a first step to design adequate Thermal processes to control clam-associated HAV outbreaks. Methods and Results Survivor curves and Thermal death curves were generated for different treatment times (0–6 min) at different temperatures (50–72°C) and Weibull and first-order models were compared. D-values for HAV ranged from 47·37 ± 1·23 to 1·55 ± 0·12 min for the first-order model and 64·43 ± 3·47 to 1·25 ± 0·45 min for the Weibull model at temperatures from 50 to 72°C. z-Values for HAV in clams were 12·97 ± 0·59°C and 14·83 ± 0·0·28°C using the Weibull and first-order model respectively. The calculated activation energies for the first-order and Weibull model were 145 and 170 kJ mole−1 respectively. Conclusion The Weibull model described the Thermal Inactivation behaviour of HAV better than the first-order model. Significance and Impact of the Study This study provides novel and precise information on Thermal Inactivation kinetics of HAV in homogenized clams. This will enable reliable Thermal process calculations for HAV Inactivation in clams and closely related seafood.
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Thermal Inactivation of foodborne enteric viruses and their viral surrogates in foods
Journal of Food Protection, 2015Co-Authors: Hayriye Bozkurt, Doris H Dsouza, Michael P DavidsonAbstract:Foodborne viruses, in particular human norovirus and hepatitis A virus, are the most common causes of food-associated infections and foodborne illness outbreaks around the world. Since it is currently not possible to cultivate human noroviruses and the wild-type strain of hepatitis A virus in vitro, the use of a variety of viral surrogates is essential to determine appropriate Thermal processing conditions to reduce the risk associated with their contamination of food. Therefore, the objectives of this review are to (i) present pertinent characteristics of enteric foodborne viruses and their viral surrogates, (ii) discuss the viral surrogates currently used in Thermal Inactivation studies and their significance and value, (iii) summarize available data on Thermal Inactivation kinetics of enteric viruses, (iv) discuss factors affecting the efficacy of Thermal treatment, (v) discuss suggested mechanisms of Thermal Inactivation, and (vi) provide insights on foodborne enteric viruses and viral surrogates for future studies and industrial applications. The overall goal of this review is to contribute to the development of appropriate Thermal processing protocols to ensure safe food for human consumption.
