Pasteurization also destroys what type of organisms that cause deterioration of milk and reduced shelf life?

• A. Pathogenic bacteria
• B. Spoilage microbes
• C. Lactic acid bacteria
• D. Enzymes only

Answer: (B)

Pasteurization lowers the number of microorganisms in milk, including those that cause spoilage. The deterioration of flavor, texture, and overall quality that shortens shelf life is mainly due to spoilage microbes—bacteria, yeasts, and molds—that produce off-flavors, souring, gas, and curdling. By reducing these populations, pasteurization helps milk stay acceptable longer. While pathogenic bacteria are also killed by this heat treatment, the question focuses on what drives quality loss and shelf life, which is best described by spoilage microbes. Enzymes aren’t organisms, and that option isn’t the primary target of pasteurization. Lactic acid bacteria are a type of spoilage organism, but the broader category of spoilage microbes is the more accurate answer.