Question

Microbiologically induced defect in cheese is
A. Mold Growth
B. Yeast Growth
C. Gassy defect in cheese
D. Discoloration in cheese
Choose the correct answer from the options given below:

• A. A, B and D only
• B. A, B and C only
• C. A, B, C and D
• D. B, C and D only

Hint:

In cheese making, microbes are both friends and foes. The key is control. The desired microbes (starter cultures, ripening flora) are friends. Uncontrolled contaminants (wild yeasts, molds, gas-producers) are foes that cause defects.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
The question asks to identify which of the listed issues are considered defects in cheese caused by microbial activity. Cheese is a complex biological system where microbial growth is sometimes desired (e.g., starter cultures, ripening flora) and sometimes leads to spoilage or defects.
Step 2: Detailed Explanation:
Let's analyze each statement:
A. Mold Growth: While some molds are essential for certain cheese varieties (e.g., Penicillium roqueforti in blue cheese), unwanted mold growth on the surface or interior of other cheeses is a common spoilage defect.
B. Yeast Growth: Uncontrolled growth of wild yeasts can lead to off-flavors, gassiness, and discoloration, which are considered defects.
C. Gassy defect in cheese: This defect, characterized by excessive holes or even splitting of the cheese block, is caused by undesirable gas-producing microorganisms like coliforms, clostridia, or certain yeasts. This is a classic microbial defect known as "early blowing" or "late blowing".
D. Discoloration in cheese: The growth of pigmented bacteria, yeasts, or molds on the cheese surface or within cracks can cause unwanted colored spots (e.g., pink, black, brown), which is a quality defect.
Since all four statements describe potential defects caused by microorganisms, they are all correct.
Step 3: Final Answer:
All listed items—Mold Growth, Yeast Growth, Gassy defect, and Discoloration—are well-known microbiologically induced defects in cheese.