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How do microorganisms cause dairy products to become rancid?
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food preservation
An overview of food preservation.
Microorganisms cause dairy products to become rancid through the biological breakdown of lipids. Specifically, certain bacteria, yeasts, and molds produce enzymes that decompose the lipids found in dairy into fatty acids and glycerol. This microbial activity is distinct from chemical rancidity, which is caused by the autoxidation of unsaturated fatty acids when exposed to oxygen.12
To prevent such microbial spoilage, the food industry employs pasteurization, a heat-treatment process designed to destroy spoilage-causing microorganisms and extend the storage life of dairy products.3