How does pasteurization prevent food spoilage?

Pasteurization is a process that heats liquids, usually milk or fruit juices, to a high temperature for a short time to kill potentially harmful bacteria. This process does not eliminate all microorganisms in the liquid, but it does reduce the number of viable organisms, including pathogens, to a level that is considered safe for human consumption. Pasteurization works by denaturing the proteins, enzymes, and nucleic acids of bacteria, which causes them to lose their structure and function and become unable to reproduce or cause illness.

The high temperature used in pasteurization also helps to inactivate enzymes that could cause spoilage, such as those that break down proteins, fats, or carbohydrates. This helps to extend the shelf life of the product by slowing down the natural process of food deterioration.

Pasteurization has been widely used in the food industry for over a century and is considered an important public health measure for reducing the risk of foodborne illness. However, it is important to note that pasteurization does not make food completely sterile, and it does not eliminate all potential hazards, such as toxins produced by bacteria before pasteurization or contamination that occurs after pasteurization.