Final answer:
The percentage of milk fat is not a factor in determining the pasteurization process. HTST and UHT are two methods of pasteurization that utilize high temperatures for short periods to ensure the safety and longevity of milk without necessarily being affected by milk fat content. The option (C) is correct.
Step-by-step explanation:
The percentage of milk fat does not determine how the milk should be pasteurized. Pasteurization is a process used to kill harmful bacteria by heating milk to a specific temperature for a set period. Two common methods of pasteurization are the high-temperature short-time (HTST) and ultra-high-temperature (UHT).
HTST pasteurization heats milk to 72 °C for 15 seconds, preserving quality and freshness. UHT pasteurization exposes milk to 138 °C for 2 seconds or more, extending shelf life up to 90 days without refrigeration, although it may alter taste and smell slightly due to changes in the milk proteins. Therefore, option (C) is correct.