What is the process called for heating liquids to prevent spoiling by bacteria and other microorganisms?

Pasteurization.

Explanation:

Pasteurization may be defined as the process of destroying the pathogens by the heating above its normal temperature. Louis Pasteur was the founder of the pasteurization process.

The liquids are heated to prevent the spoiling by microorganisms and bacteria. The spoiled enzymes can also be inactivated by the process of the pasteurization.

Thus, the answer is pasteurization.