Final answer:
Killing microorganisms in milk using high temperatures is known as pasteurization, with UHT pasteurization being a specific method that uses ultra-high temperatures to sterilize milk for long-term storage without refrigeration.
Step-by-step explanation:
The killing of microorganisms in milk using high temperature is known as pasteurization. Specifically, the UHT pasteurization method exposes milk to ultra-high temperatures, approximately 138 °C, for a few seconds. This process effectively sterilizes the milk, allowing it to be sealed and stored for extended periods without the need for refrigeration, unlike the high-temperature short-time (HTST) pasteurization, which requires refrigerated storage. UHT pasteurization is particularly beneficial where access to refrigeration is limited, as it keeps the milk safe for consumption for up to 90 days when stored in airtight containers.
Pasteurization techniques not only kill pathogens such as Salmonella and E. coli but also significantly reduce the number of microbes that cause food spoilage. This method helps in maintaining the sensory qualities of the milk to a substantial degree, although UHT-treated milk may undergo slight changes in taste and smell due to the alteration of proteins under the very high temperatures.