scholarly journals Thermal Inactivation of Different Capripox Virus Isolates

2020 ◽  
Vol 8 (12) ◽  
pp. 2053
Author(s):  
Janika Wolff ◽  
Martin Beer ◽  
Bernd Hoffmann
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution ◽  
Thermal Inactivation ◽  
Temperature Profiles ◽  
Thermal Stabilities ◽  
Fail Safe ◽  
Virus Isolates

Capripox viruses (CaPVs) cause a highly contagious poxvirus disease of livestock animals. Working with CaPVs requires laboratories with a high biosecurity level (BSL 3), and reliable inactivation of these viruses is therefore necessary for working in areas or laboratories with a lower biosecurity status. Heat treatment provides a simple and well-established tool for the inactivation due to its substantial advantages (e.g., easy to perform, fast, cheap, and robust). In our study, we determined the time–temperature profiles needed for a fail-safe inactivation procedure using four different CaPV isolates in aqueous solution with and without the addition of protective serum. All four tested CaPV isolates were completely inactivated after 30 min at 56 °C or 10 min at 60 °C. Since different thermal stabilities of other CaPV isolates could not be fully excluded, we recommend an inactivation procedure of 1 h at 56 °C for safe shipment or working in laboratories with lower biosecurity levels than BSL 3.

Bacteriocin Produced from Lactobacillus plantarum ATM11: Kinetic and Thermodynamic Studies

2016 ◽  
Vol 12 (5) ◽  
pp. 501-505 ◽  
Author(s):  
A. Thirumurugan ◽  
S. Ramachandran ◽  
S. Sivamani
Keyword(s):  
Heat Treatment ◽  
Lactobacillus Plantarum ◽  
Food Industry ◽  
Thermal Inactivation ◽  
Heating Temperature ◽  
Food Matrix ◽  
Thermal Stabilities ◽  
Kinetic And Thermodynamic Parameters ◽  
Heat Stable ◽  
Kinetic And Thermodynamic Studies

Abstract In the present study, the effect of heat treatment on the activity of bacteriocin from Lactobacillus plantarum ATM11 was studied. The kinetic and thermodynamic parameters were calculated for the thermal inactivation of the bacteriocin over a time–temperature combinations in the range of 30, 45, 60 and 90 min and 60, 65, 70, 75 and 80 °C. Understanding the thermal inactivation of biopreservatives in a food matrix is essential to allow their proper utilization in food industry, enabling the reduction of heating times and optimization of heating temperature. The results indicate the different thermal stabilities with k-values between 0.0159 and 0.0225 min−1. D-values decreased with increase in temperature, indicating faster inactivation of the bacteriocin at higher temperatures. These results suggest that bacteriocin is relatively heat stable with a z-value of 22.85 °C.

Binding of 3-phosphoglycerate leads to both activation and stabilisation of ADP-glucose pyrophosphorylase from apple leaves

2005 ◽  
Vol 32 (9) ◽  
pp. 839
Author(s):  
Rui Zhou ◽  
Lailiang Cheng
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Enzyme Activity ◽  
Inorganic Phosphate ◽  
Thermal Inactivation ◽  
Specific Activity ◽  
Apple Leaves ◽  
Apparent Homogeneity ◽  
Adp Glucose Pyrophosphorylase ◽  
High Concentrations

Apple leaf ADP-glucose pyrophosphorylase was purified 1436-fold to apparent homogeneity with a specific activity of 58.9 units mg–1. The enzyme was activated by 3-phosphoglycerate (PGA) and inhibited by inorganic phosphate (Pi) in the ADPG synthesis direction. In the pyrophosphorolytic direction, however, high concentrations of PGA (> 2.5 mm) inhibited the enzyme activity. The enzyme was resistant to thermal inactivation with a T0.5 (temperature at which 50% of the enzyme activity is lost after 5 min incubation) of 52°C. Incubation with 2 mm PGA or 2 mm Pi increased T0.5 to 68°C. Incubation with 2 mm dithiothreitol (DTT) decreased T0.5 to 42°C, whereas inclusion of 2 mm PGA in the DTT incubation maintained T0.5 at 52°C. DTT-induced decrease in thermal stability was accompanied by monomerisation of the small subunits. Presence of PGA in the DTT incubation did not alter the monomerisation of the small subunits of the enzyme induced by DTT. These findings indicate that binding of PGA renders apple leaf AGPase with a conformation that is not only more efficient in catalysis but also more stable to heat treatment. The physiological significance of the protective effect of PGA on thermal inactivation of AGPase is discussed.

scholarly journals Adsorption of Copper Ion in Acidic Aqueous Solution Using Rice Bran and Heat Treatment

2008 ◽  
Vol 31 (12) ◽  
pp. 749-754
Author(s):  
Kazuhiro HONDA ◽  
Takayuki YOSHIKAWA ◽  
Tuyoshi SASAKI ◽  
Tadashi SASAMOTO
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution ◽  
Rice Bran ◽  
Copper Ion ◽  
Acidic Aqueous Solution

Applying the Food Safety Objective and Related Standards to Thermal Inactivation of Salmonella in Poultry Meat

2007 ◽  
Vol 70 (9) ◽  
pp. 2036-2044 ◽  
Author(s):  
JEANNE-MARIE MEMBRÉ ◽  
JOHN BASSETT ◽  
LEON G. M. GORRIS
Keyword(s):  
Heat Treatment ◽  
Food Safety ◽  
Process Design ◽  
Thermal Inactivation ◽  
Probabilistic Approach ◽  
Competent Authority ◽  
Minimum Time ◽  
Poultry Meat ◽  
Fixed Temperature ◽  
Design Calculations

The objective of this study was to investigate the practicality of designing a heat treatment process in a food manufacturing operation for a product governed by a Food Safety Objective (FSO). Salmonella in cooked poultry meat was taken as the working example. Although there is no FSO for this product in current legislation, this may change in the (near) future. Four different process design calculations were explored by means of deterministic and probabilistic approaches to mathematical data handling and modeling. It was found that the probabilistic approach was a more objective, transparent, and quantifiable approach to establish the stringency of food safety management systems. It also allowed the introduction of specific prevalence rates. The key input analyzed in this study was the minimum time required for the heat treatment at a fixed temperature to produce a product that complied with the criterion for product safety, i.e., the FSO. By means of the four alternative process design calculations, the minimum time requirement at 70°C was established and ranged from 0.26 to 0.43 min. This is comparable to the U.S. regulation recommendations and significantly less than that of 2 min at 70°C used, for instance, in the United Kingdom regulation concerning vegetative microorganisms in ready-to-eat foods. However, the objective of this study was not to challenge existing regulations but to provide an illustration of how an FSO established by a competent authority can guide decisions on safe product and process designs in practical operation; it hopefully contributes to the collaborative work between regulators, academia, and industries that need to continue learning and gaining experience from each other in order to translate risk-based concepts such as the FSO into everyday operational practice.

scholarly journals EFFECT OF CHEMICAL AND THERMAL TREATMENTS ON INHIBITION OF PEROXIDASE ACTIVITIE OF PURPLE SKIN EGGPLANT (SOLANUMMELONGENA L.)

2021 ◽  
Vol 9 (04) ◽  
pp. 304-313
Author(s):  
Jocelyn Constant Yapi ◽  
◽  
Jean Bedel Fagbohoun ◽  
Zranseu Ange Benedicte Deffan ◽  
Elvis Gbocho Serge Ekissi ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Thermal Inactivation ◽  
Solanum Melongena ◽  
Thermal Treatments ◽  
Optimal Temperature ◽  
Spectrophotometric Methods ◽  
Acid Effect ◽  
Fresh Cut ◽  
D Values ◽  
Increasing Temperature

Peroxidase (POD) associated with the browning of fresh-cut fruits and vegetableswas extracted from purple skin eggplant(Solanum melongena L.) and characterised using reliable spectrophotometric methods. Maximal POD activity was found at 35 °C and pH 6.0 with guaiacol as the substrate. The enzyme was stable at his optimal temperature (35 °C) and hisat pH stability was in the range of 5.6 - 6.6.Peroxidase retained its full activity in the presence of ion K+, Cu2+, Na+, Pb2+ and Ba2+ but were inhibited strongly by the ion Fe2+ and Mg2+ and the reducing agents as sodium thiosulfateand ascorbic acid. Effect of heattreatment on eggplant peroxidase showed that D-values decreased with increasing temperature, indicating faster peroxidase inactivation at higher temperatures.At 60 °C, the D-values ranged from 20.42 to 54.24 min. Hence, heat treatment at 60 °C for 30 min reduced browning of eggplant fruit.These data can be used to predict prevention of browning in the purple skin eggplantby thermal inactivation and the use of chimical agents onthe enzyme.

scholarly journals Highly Mixed ZrO2/SiO2 Hybrid Aerogel Deriving from Freely Tangled Weakly Branched Primary Clusters Enables Improved Thermal Stability and Excellent Thermal Insulating Performance.

2019 ◽  
Author(s):  
Benxue Liu ◽  
Min Gao
Keyword(s):  
Heat Treatment ◽  
Thermal Stability ◽  
Sol Gel ◽  
Single Component ◽  
Thermal Stabilities ◽  
Crystallization Behaviors ◽  
Thermal Insulating ◽  
Enhanced Properties ◽  
Hybrid Aerogels ◽  
Hybrid Aerogel

In compared with single component aerogel, hybrid aerogel with multi-components possessing enhanced properties, especially high thermal stabilities which are our concerns in this paper, are the promised materials in various applications. However, how the mixing between variable components within hybrid aerogel affects their properties still not very clear and needs more research efforts. In the present research, we chose a ZrO<sub>2</sub>/SiO<sub>2</sub> hybrid aerogel as represent to study their mixing and the resulted thermal stabilities. We designed a series of ZrO<sub>2</sub>/SiO<sub>2</sub> hybrid aerogels with variable ZrO<sub>2</sub>/SiO<sub>2</sub> ratio deriving from tailored sol-gel parameters, and then studied their shrinkages, nanopore collapses and crystallization behaviors upon heat-treatment.

Thermal Inactivation of Listeria monocytogenes in Chicken Gravy

1992 ◽  
Vol 55 (7) ◽  
pp. 492-496 ◽  
Author(s):  
I-PING D. HUANG ◽  
AHMED E. YOUSEF ◽  
ELMER H. MARTH ◽  
M. EILEEN MATTHEWS
Keyword(s):  
Heat Treatment ◽  
Listeria Monocytogenes ◽  
Heat Resistance ◽  
Thermal Inactivation ◽  
Refrigerated Storage ◽  
Department Of Agriculture ◽  
Large Numbers ◽  
Z Value ◽  
D Values ◽  
The U.S

Heat resistance of Listeria monocytogenes strains V7 and Scott A in chicken gravy and changes in heat resistance during refrigerated storage were studied. After chicken gravy was made, it was cooled to 40°C, inoculated with 105 CFU L. monocytogenes per ml of gravy, and then stored at 7°C for 10 d. Gravy was heated at 50, 55, 60, and 65°C immediately after inoculation and after 1, 3, 5, and 10 d of refrigerated storage. The D values for strains Scott A and V7 in gravy heated at 50°C at day 0 were 119 and 195 min and at day 10 they were 115 and 119 min, respectively, whereas at 65°C comparable values at day 0 were 0.48 and 0.19 min and at day 10 they were 0.014 and 0.007 min. Heat resistance (expressed as D values) was greater at day 0 than at the end of refrigerated storage. The z values ranged from 3.41 to 6.10°C and were highest at the early stages of chill storage and then decreased at the later stages. Strain V7 was more heat resistant than Scott A at 50°C. Strain Scott A always had a higher z value than did strain V7 at the same storage interval. A heat treatment greater than the 4-D process recommended by the U.S. Department of Agriculture was required to inactivate the large numbers of L. monocytogenes that developed in chicken gravy during refrigerated storage.

Heat treatment of Disk-Saw teeth in an aqueous solution of PK-2 polymer

2007 ◽  
Vol 37 (4) ◽  
pp. 348-349
Author(s):  
G. N. Tarasova ◽  
T. N. Oskolkova
Keyword(s):  
Heat Treatment ◽  
Aqueous Solution

In vivo characterization of thermal stabilities of Aeropyrum pernix cellular components by differential scanning calorimetry

2007 ◽  
Vol 53 (9) ◽  
pp. 1038-1045 ◽  
Author(s):  
Igor Milek ◽  
Miha Črnigoj ◽  
Nataša Poklar Ulrih ◽  
Gönül Kaletunç
Keyword(s):  
Heat Treatment ◽  
Differential Scanning Calorimetry ◽  
Optical Data ◽  
Lag Phase ◽  
Scanning Calorimetry ◽  
Thermal Stabilities ◽  
Whole Cell ◽  
Whole Cells ◽  
Aeropyrum Pernix ◽  
Cellular Components

Revival studies of Aeropyrum pernix show that the viability of cells and cell recovery after heat treatment depends on the temperature of treatment. Differential scanning calorimetry (DSC) is used to analyze the relative thermal stabilities of cellular components of A. pernix and to identify the cellular components responsible for the observed lag phase and reduced maximum growth following a heat treatment. DSC thermograms show 5 visible endothermic transitions with 2 major transitions. DSC analysis of isolated crude ribosomes aids the assignment of the 2 major peaks observed in whole-cell thermograms to denaturation of ribosomal structures. A comparison of partial and immediate full rescan thermograms of A. pernix whole cells indicates that both major peaks represent irreversible thermal transitions. A DNA peak is also identified in the whole-cell thermogram by comparison with the optical data of isolated pure DNA. DNA melting is shown to be irreversible in dilute solution, whereas it is partially reversible in whole cells, owing at least in part, to restricted volume effects. In contrast to mesophilic organisms, hyperthermophilic A. pernix ribosomes are more thermally stable than DNA, but in both organisms, irreversible changes leading to cell death occur owing to ribosomal denaturation.

Heat therapy of virus-infected cultures of the cultivated mushroom Agaricus bisporus

1973 ◽  
Vol 24 (4) ◽  
pp. 553 ◽  
Author(s):  
NG Nair
Keyword(s):  
Heat Treatment ◽  
Growth Rate ◽  
Agaricus Bisporus ◽  
Thermal Inactivation ◽  
Treatment Time ◽  
Virus Particles ◽  
Heat Therapy ◽  
Cultivated Mushroom ◽  
Pre Treatment

A procedure for elimination of viruses by heat treatment of virus-infected isolates of the cultivated mushroom Agaricus bisporus has been perfected. A minimum treatment time of 3 weeks at 33�C was required. The effect of heat treatment was assessed in terms of increased growth of the isolates in vitro and absence of virus particles. Growth rate was not always a good measure of effective heat treatment. Some virus-infected isolates were found which can act as symptomless carriers. The effect of heat treatment appeared to depend on the pre-treatment which the isolates had received. Elimination of viruses did not occur when the isolates were grown at 25� prior to heat treatment. It appears, therefore, that thermal inactivation of viruses is not complete in mature mycelium.

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