Question

Flat sour in canned food is caused by:

• A. Clostridium botulinum
• B. Bacillus stearothermophillus
• C. Saccharomyces cerevisiae
• D. Lactobacillus plantarum

Hint:

Lactobacilli are key players in many fermented foods and can cause specific types of spoilage under anaerobic conditions.

Answer 1

The Correct Option is D

Step 1: Concept
Flat souring in canned food is a result of anaerobic bacterial activity that produces lactic acid, leading to the breakdown of sugars into acids without producing gas.

Step 2: Meaning
Flat souring refers to the process where canned foods develop an acidic taste due to fermentation by certain bacteria under anaerobic conditions. This does not produce the same carbonation or foaming as other types of spoilage.

Step 3: Analysis
- Clostridium botulinum (A): Known for producing botulism toxin, it is a strict anaerobe but causes gas gangrene and food poisoning rather than flat souring. - Bacillus stearothermophillus (B): This bacterium can survive high temperatures and is associated with thermal processing issues in canned foods. It does not typically cause flat souring. - Saccharomyces cerevisiae (C): Commonly known as baker's yeast, it ferments sugars to produce ethanol and CO2, leading to foaming and carbonation rather than the acidic taste of flat souring. - Lactobacillus plantarum (D): This bacterium is well-known for its ability to ferment sugars into lactic acid under anaerobic conditions. It is commonly found in fermented foods and is responsible for the characteristic flavor and texture changes associated with flat souring.

Step 4: Conclusion
The correct cause of flat souring in canned food is due to the activity of Lactobacillus plantarum, which ferments sugars into lactic acid without producing gas or significant carbonation. Final Answer: (D)