Final answer:
The process of heating milk to eliminate bacteria is known as pasteurization, with UHT and HTST being the commonly used methods for long-term and refrigerated storage respectively. option b is correct.
Step-by-step explanation:
The process by which milk is heated to a very high temperature to kill bacteria is called pasteurization. One method of pasteurization is ultra-high temperature (UHT) pasteurization wherein the milk is heated to 138 °C for at least 2 seconds. This method effectively sterilizes the milk, allowing it to be sealed and stored for long periods without refrigeration.
UHT pasteurization makes it possible to prolong the shelf life of milk, especially in regions where refrigeration is limited. On the other hand, high-temperature short-time (HTST) pasteurization heats milk to 72 °C for about 15 seconds and is commonly used for milk that will be refrigerated. Both HTST and UHT pasteurization are methods used to reduce microbial loads to safe levels while maintaining the sensory quality of milk.