Heated Canned Foods Questions

• Canned foods – If a heat-processed can contains viable non-spore-forming bacteria, what is the most likely route/source indicating container leakage?
• Swelled cans in acid/medium-acid foods – The butyric acid type of fermentation with CO2 and H2 gas production is caused by which Clostridia?
• “Sulfur stinker” spoilage – In which product category is this spoilage (due to sulfide-producing anaerobes) uncommonly found?
• Canned poultry spoilage — which group is more common? In commercial canning, poultry products are more frequently spoiled by which clostridial activity pattern?
• Osmotolerant spoilage in high-sugar foods: Which molds can grow in jellies and candied fruits up to about 67.5% sugar?
• Proteolytic (putrefactive) can spoilage indicators: Which Clostridium species produce H2S, mercaptans, ammonia, indole, and skatole from proteins?
• Hydrogen swell (chemical can spoilage): Which conditions favor hydrogen swell development in canned foods?
• Canned dairy defects (milk, cream, evaporated milk): Which organisms commonly cause bitterness, acidity, and curdling?
• Canned acidic fruits (pineapple, tomatoes, pears): Spoilage by Clostridium pasteurianum is more likely when product pH is…
• pH and can defects: Foods with pH above about 5.3 are especially subject to which spoilage pattern?
• Acid foods (pH 4.5–3.7): Which spoilers are most often responsible for defects in this pH band?
• Canned meat and fish spoilage — principal sporeformers: Which groups are most commonly involved?
• Flat sour contamination source: What is the immediate, most common source of flat sour bacteria in canneries?
• Canned dairy quality — thickening defect in sweetened condensed milk In industrial food microbiology, canned sweetened condensed milk may become abnormally thick or “ropy.” Which group of microorganisms is most commonly implicated as the cause of this thickening defect under storage conditions?
• Thermophilic spoilage in acid juices — factors enabling Bacillus coagulans in tomato juice The ability of Bacillus coagulans to grow and cause spoilage in processed tomato juice primarily depends on which combination of factors?
• Canning microbiology — expected spoilage in medium-acid foods (pH 5.3 to 4.5) Medium-acid, canned foods with pH between 5.3 and 4.5 are most likely to undergo which specific type of spoilage if processing or storage conditions are inadequate?
• Flat-sour spoilage agents in acid canned foods Flat-sour spoilage of acidic canned foods is classically attributed to which organism(s)? Choose the best answer for acid food matrices.
• Putrefactive anaerobes in canning — preferred growth in relation to food acidity Putrefactive anaerobes that cause gas and foul odor in canned foods grow best in which acidity class of canned products?
• Spoilage of very high-acid canned foods (pH < 3.7) Highly acidic canned foods with pH below 3.7 are most likely to experience which outcome with respect to microbial spoilage under proper hermetic sealing?