Thermal Destruction in Food Preservation

The process of transferring energy from one part of a substance to another due to a temperature difference.

A type of food poisoning caused by the bacterium Clostridium botulinum. It thrives in moist, low-acid environments with limited oxygen and temperatures between 5°C and 50°C.

Foods with a pH level of 3.0 or lower, such as fruits and tomatoes. They require mild heat processing to kill bacteria that spoil the food.

Foods with a pH level of 4.6 or higher, such as vegetables, meats, and fish. These require high heat processing to destroy bacterial spores, preventing botulism.

The process of applying heat to food to kill microorganisms and enzymes that could cause spoilage or botulism.

This historical event marked the beginning of food canning. In 1809, a French man named Nicholas Appert was awarded a prize for his invention.

This historical event marked the significance of controlling C. botulinum in canned foods to prevent food poisoning. The importance of killing this harmful bacterium during canning was established.

The number of degrees Fahrenheit or Celsius required for the thermal destruction curve to shift by one log cycle.

The time needed to achieve a certain level of bacteria destruction. Usually expressed as a multiple of the D-value.

The equivalent minutes at 250°F (121°C) at the slowest heating point in the container. Represents the total lethality delivered.

The time required to reduce the population of microorganisms by 90% at a specific temperature.

The population of microorganisms after heat treatment will be 1 million.

The coldest point within the food during heat treatment, considering factors like shape and heat transfer method.

The size of the food container, which influences heat penetration and processing time.

The process of heating milk to a specific temperature for a set time to kill harmful bacteria, extending its shelf life.

The composition of the food, including acidity, moisture, and density, affects how heat travels through it.

A bacterium that causes Q fever, considered a potential contaminant in milk.

The way heat is transferred, either by conduction (direct contact) or convection (moving fluids).

A bacterium that causes tuberculosis, previously a concern in milk safety.

The time required for the coldest point in the food to reach the target temperature during heat treatment.

A milk pasteurization method where milk is heated to 63°C for 30 minutes.

The combined lethal effects of heat during the entire process, including heating and cooling.

The time it takes to reduce the number of viable bacteria by 90% at a specific temperature, representing the rate of bacterial death.

A milk pasteurization method where milk is heated to 72°C for 15-16 seconds.

The process where bacterial death occurs at a gradual and predictable rate as they are exposed to heat.

A milk sterilization method where milk is heated to 135-140°C for a few seconds.

A process applied to fruits and vegetables to inactivate enzymes, preparing them for freezing.

The number of viable bacteria decreases exponentially over time at a given lethal temperature.

The time it takes for bacteria to die is affected by factors such as acidity, sugar content, fat content, and the method of heating.

A mild heat treatment that kills pathogens, reduces bacteria, and inactivates enzymes, resulting in a short shelf life.

A severe heat treatment that kills all bacteria, making food commercially sterile with a long shelf life.

A type of microorganism that thrives in very high temperatures, often above 45°C.

A type of microorganism that thrives in moderate temperatures, typically between 20°C and 45°C.

The ability of a microorganism to survive and grow in the presence of a certain amount of heat. For example, Clostridium botulinum has high heat resistance, meaning it survives well at high temperatures.

The specific temperature at which a microorganism is killed within a certain timeframe. This is often used in food processing to ensure the destruction of harmful bacteria.

A microorganism that thrives in the absence of oxygen. This is often important to consider in food preservation, as Clostridium botulinum is an anaerobic bacterium that can survive without oxygen.

The medium in which a microorganism grows. This can affect its heat resistance and its D-value.

The substance in which bacteria are suspended. This can influence their heat resistance and D-value because different substances conduct heat differently.

A bacterial group known for causing flat-sour spoilage in food. This group is relatively heat-resistant and includes Bacillus stearothermophilus.

A bacterial group known for causing gaseous spoilage in food. This group is also relatively heat-resistant and includes Clostridium thermosaccharolyticum.