# What is the significance of thermal death point and thermal death time with respect to sterilization?

## What is the significance of thermal death point and thermal death time with respect to sterilization?

A similar parameter, the thermal death time (TDT), is the length of time needed to kill all microorganisms in a sample at a given temperature. These parameters are often used to describe sterilization procedures that use high heat, such as autoclaving.

## What is the effect of temperature on thermal death time?

The thermal death time of microorganisms can vary, depending on the thermal tolerance of the microbes. For example, thermophilic bacteria such as Thermophilus aquaticus that can tolerate high temperatures will have a thermal death time that is longer than the more heat-sensitive bacterium Escherichia coli .

What is thermal death point in microbiology?

: the temperature at which all organisms of a culture will be killed by heat either instantaneously or within an arbitrary brief finite period.

What is used for determination of thermal death time?

Take two nutrient agar plate and divide it into five quadrants. On each quadrant assign time like 0.15 sec, 2 min, 5 min, 15 min. This time will depict at particular temperature for how much time the organism was heated. Now take your sample culture that were heated in different temperatures.

### What is the purpose of thermal death point?

Thermal Death Point (TDP) The TDP is the lowest temperature that is required to kill a population of microbes when applied for a specific time.

### What is thermal death curve?

A thermal death curve for this process is shown below. It is a logarithmic process, meaning that in a given time interval and at a given temperature, the same percentage of the bacterial population will be destroyed regardless of the population present.

What is the 12 D process?

12D concept refers to thermal processing requirements designed to reduce the probability of survival of the most heat resistant C. botulinum spores to 10-12. This helps to determine the time required at process temperature of 121oC to reduce spores of C.

What temperature is pasteurization?

Pasteurization of milk, widely practiced in several countries, notably the United States, requires temperatures of about 63 °C (145 °F) maintained for 30 minutes or, alternatively, heating to a higher temperature, 72 °C (162 °F), and holding for 15 seconds (and yet higher temperatures for shorter periods of time).

#### What do you mean by thermal death time?

Thermal death time is how long it takes to kill a specific bacterium at a specific temperature. It was originally developed for food canning and has found applications in cosmetics, producing salmonella-free feeds for animals (e.g. poultry) and pharmaceuticals.

#### What is D and z-value?

The D-value of an organism is the time required in a given medium, at a given temperature, for a ten-fold reduction in the number of organisms. While the D-value gives the time needed at a certain temperature to kill 90% of the organisms, the z-value relates the resistance of an organism to differing temperatures.

How many degrees does it take to kill bacteria?

165 degrees
The only way to kill bacteria by temperature is by cooking food at temperatures of 165 degrees or more. Bacteria also die in highly acidic environments like pickle juice.

Which is the correct definition of thermal death point?

thermal death point The lowest temperature necessary to kill all of the microorganisms present in a culture in 10 minutes. thermal death time The minimal time necessary to kill all microorganisms present in a culture held at a given temperature.

## How long does it take to kill microorganisms at thermal death point?

thermal death point. The lowest temperature necessary to kill all of the microorganisms present in a culture in 10 minutes. thermal death time. The minimal time necessary to kill all microorganisms present in a culture held at a given temperature.

## How does a thermal death curve work for bacteria?

When was the discovery of thermal death time?

It would pave the way for thermal death time research that was pioneered by Bigelow and C. Olin Ball from 1921 to 1936 at the National Canners Association (NCA). Bigelow and Ball’s research focused on the thermal death time of Clostridium botulinum ( C. botulinum) that was determined in the early 1920s.