Topics:
Animal Refresher, Meat Science
Causative Organism of Flat Sour Spoilage in Canned Meat
Flat sour of canned meat is caused by:
- Bacillus coagulans only
- Bacillus stearothermophilus only
- Both Bacillus coagulans and Bacillus stearothermophilus — Correct Answer
- Clostridium spp.
Explanation:
Correct Answer: Both Bacillus coagulans and Bacillus stearothermophilus
Flat Sour spoilage of canned meat is caused by Bacillus coagulans and Bacillus stearothermophilus — thermophilic, aerobic/facultative, spore-forming bacteria.
Characteristics of Flat Sour Spoilage
- The can remains flat (no swelling/gas production) — hence the name 'flat sour'.
- The product becomes sour (lactic acid produced by fermentation of carbohydrates) without gas.
- There is no visual indicator that the can is spoiled — it looks perfectly normal from outside.
- This makes flat sour particularly dangerous from a consumer perspective.
Why No Swelling?
- These bacteria are homofermentative — they produce only lactic acid, not gas (CO₂ or H₂).
- Absence of gas = no pressure build-up = no can swelling.
Related Organism
- Bacillus stearothermophilus — causes flat sour in low-acid canned goods (vegetables, meat); used as the biological indicator (BI) for moist heat sterilization (autoclave validation).
📚 About this Topic — Animal Refresher
This multiple choice question is from Animal Refresher, Meat Science. It has 4 options with a detailed explanation of the correct answer. Practice more MCQs from Animal Refresher to strengthen your preparation.
