Final answer:
Milk pasteurization is a process that uses heat to reduce bacterial presence while preserving quality. The HTST method heats milk to 72 °C for 15 seconds, and the UHT method heats milk to 138 °C for at least 2 seconds and allows storage without refrigeration for up to 90 days, although it may alter taste and smell.
Step-by-step explanation:
The process described in the student's question refers to the methods used for milk pasteurization. There are different pasteurization techniques, and each balances temperature and time differently to reduce the presence of bacteria while maintaining the milk's quality. The most common method is high-temperature short-time (HTST) pasteurization. In HTST, milk is heated to 72 °C for 15 seconds. However, another method known as ultra-high-temperature (UHT) pasteurization heats the milk to 138 °C for at least 2 seconds. UHT pasteurized milk is then sealed in airtight containers and can be stored for a prolonged period without refrigeration, up to 90 days. While ideal for areas with limited access to refrigeration, the very high temperatures involved in UHT pasteurization can alter the milk's proteins, affecting its taste and smell.
Alternative milk refers to non-dairy milk alternatives such as soy milk, almond milk, or oat milk. To pasteurize alternative milk, similar methods can be used as for regular milk. One common method is UHT (ultra-high-temperature) pasteurization, where the milk is heated at 138 °C for 2 or more seconds and then sealed in airtight containers.
This process kills bacteria and extends the shelf life of alternative milk without the need for refrigeration, making it advantageous in regions with limited access to refrigeration.