Final answer:
Improper refrigeration of milk during transportation leads to faster spoilage due to increased molecular energy allowing spoilage reactions. Pasteurization methods reduce bacterial presence but inadequate storage still poses health risks.
Step-by-step explanation:
If milk is not refrigerated properly during transportation, the higher temperatures can lead to increased molecular activity, which facilitates spoilage reactions. Since the molecules in the milk will have more energy at room temperature, this energy allows them to overcome the activation energy barrier needed for spoilage reactions to occur.
Over time, this leads to the milk becoming soured as more molecules react. Pasteurization, including high-temperature short-time (HTST) and ultra-high-temperature (UHT) methods, can reduce the number of bacteria present in milk to delay spoilage.
UHT is particularly effective as it allows milk to be stored for longer periods without refrigeration. However, if unpasteurized or improperly stored post-pasteurization, milk can harbor harmful organisms like Salmonella and E. coli, leading to foodborne illness.