Canning and Fish Packaging Technology

Unit 4 - Thermal process for canned foods

4.5.1.Measures of Heat resistance of Microorganisms
The earliest method is “thermal death point” which is the lowest temperature beyond which when heated, the organism ceases to grow or multiply. This found limited use in thermal process calculations because killing of bacteria is dependent on time, temperature and number of bacteria. Later the concept of “Thermal Death Time(TDT)” was introduced. TDT is defined as the minimum time in minutes required to destroy a given bacterial population at a specified lethal temperature.