Question

The spoilage of sulfur stinker in canned food is caused by the following

• C. botulinum
• C. nigrificans
• B. coagulans
• B. stearothermophilus

Hint:

Remember:
- "Flat sour" spoilage = Bacillus stearothermophilus (produces acid but no gas; can ends remain flat).
- "Sulfur stinker" spoilage = Clostridium nigrificans (produces \(\text{H}_2\text{S}\) and blackening; can ends remain flat).

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Canned food spoilage can be caused by thermophilic anaerobic bacteria that survive inadequate heat sterilization.

Step 2: Detailed Explanation:
"Sulfur stinker" is a distinct type of spoilage occurring in low-acid canned foods (such as canned fish).
It is caused by the obligate thermophilic anaerobe Clostridium nigrificans (also known as Desulfotomaculum nigrificans).
This bacterium metabolizes sulfur-containing amino acids to produce hydrogen sulfide (\(\text{H}_2\text{S}\)) gas.
The gas dissolves in the liquid, imparting a highly offensive "rotten egg" odor.
Additionally, the \(\text{H}_2\text{S}\) reacts with the iron of the tin can to produce black iron sulfide, causing intense black discoloration of the can interior and food contents.
Because the gas is highly soluble in the water of the can, the can ends usually remain flat (no swelling occurs).

Step 3: Final Answer:
The spoilage is caused by C. nigrificans, which corresponds to option (B).