Which of the following is NOT listed as a type of microorganism that can contaminate dairy products?

• A. Spoilage bacteria
• B. Fecal indicators
• C. Pathogens
• D. Beneficial bacteria

Answer: (D)

Contamination in dairy products comes from microorganisms that cause spoilage or illness. Spoilage bacteria are a concern because they change flavor, texture, and odor, making the product unfit for use. Fecal indicators point to possible fecal contamination and the potential presence of pathogens, signaling a sanitation problem that needs investigation. Pathogens are disease-causing microbes that can lead to illness if the product is consumed. Beneficial bacteria, on the other hand, are intentionally added as starter cultures to drive fermentation and develop the desired texture and flavor in products like yogurt and cheese; they are not considered contaminants. Therefore, the option that is not a contaminant type is beneficial bacteria.