PSYC 2390 Lecture Notes - Lecture 3: Thermal Death Time, Freezing-Point Depression, Acidulant

• School: University of Guelph
• Department: Psychology
• Course: PSYC 2390
• Professor: Lana Trick

Document Summary

Heating is applied to the canning of foods as well. The specific time and temperature of heating is defined by the tdt, thermal death time, which identifies the parameters required to destroy the spores. This bacterium is pathogenic, producing disease in humans by making a deadly toxin. In this case, the toxin is released into the food prior to the consumption, causing food intoxication: low-temperature treatment refers to cold storage: refrigeration and freezing. During freezing, water molecules in foods begin to form ordered ice crystal structures, which pack together and restrict molecular freedom of movement: direct expansion refrigeration is a common method that pumps a gaseous refrigerant through a coil. The refrigerant expands as it moves through the coil, and air moving over the coils cools and then cools the food product: three general types of refrigerant gases are in use: liquid nitrogen, carbon dioxide, and ammonia.