Final answer:
Milk must be pasteurized to ensure safety, with UHT pasteurization allowing storage up to 90 days without refrigeration. This process alters the taste slightly but ensures the milk is sterile and safe to drink. Pasteurization kills harmful microorganisms, making it imperative for consumer health.
Step-by-step explanation:
Milk and milk products are required to undergo pasteurization to ensure safety for consumption. This process eliminates harmful microorganisms, such as Campylobacter jejuni, Salmonella spp., and E. coli. Two widely recognized methods for milk pasteurization are high-temperature short-time (HTST) and ultra-high-temperature (UHT). HTST involves heating milk to 72°C for at least 15 seconds. In contrast, UHT pasteurization treats milk at about 138°C for 2 seconds or more, which allows it to be stored for up to 90 days without refrigeration when sealed in airtight containers. This process is particularly beneficial in areas without consistent access to refrigeration.
Due to the UHT pasteurization, milk is modified slightly in taste and smell because the high temperatures alter its proteins. Despite these changes, the health benefits of sterilizing milk and protecting it from contamination outweigh any minor alterations in its characteristics. The shelf life of milk products is indicated by 'sell-by dates,' which vary based on the pasteurization method used and any additional processing. Consumers should always check these dates before purchasing milk products to ensure they are acquiring a fresh product.
Milkborne organisms killed by pasteurization include a comprehensive list of pathogenic bacteria, which is why raw, unpasteurized milk is considered unsafe for consumption. Pasteurization, a process originally developed by Louis Pasteur in the 1860s, has historically improved the safety of milk, making it one of the most significant advances in food safety of its time.