Skip to comments.Spoilage in canned food products
Posted on 08/01/2013 5:31:14 PM PDT by djf
SPOILAGE IN CANNED FOOD PRODUCTS
By: Stephanie Hoffman, CSU Food Science Graduate Student - Fall 2008
The safety of commercially canned foods is generally not of concern to consumers, but recent national recalls of canned chili products and institutional-size cans of vegetables due to potential contamination with Clostridium botulinum is a reminder that store-bought canned goods can be implicated in foodborne illness outbreaks. These were the first recalls of commercially canned foods in the U.S. linked to botulism in 33 years and improper processing that allowed the survival of C. botulinum spores appears to have been the cause. Home canners and commercial manufacturers both rely on time-tested processes to insure the inactivation of this deadly microorganism. Proper cooking temperatures, times and pressure, along with well-maintained equipment are all necessary to prevent the survival of C. botulinum.
How can consumers help protect themselves? One important way is to look for signs of spoilage and to immediately discard any canned foods that are suspected of being spoiled.
Here are the terms used in the industry to describe canned foods with signs of spoilage:
Soft Swell: A can that is bulged on both ends, but not so tightly that the ends can't be pushed in somewhat with a thumb press.
Hard Swell: A can that is so tightly bulged on both ends that the ends can't be pressed in. A can with a hard swell will generally "buckle" before it bursts.
Flipper: A can whose end normally looks flat, but "flips out" when struck sharply on one end.
Springer: A can with one end bulged out. With sufficient pressure, this end will flip in, but the other end will flip out.
Leaker: A can with a crack or hole in the container that has caused leakage.
Flipper and Springer cans do not always indicate microbial spoilage, but are often an indication of contamination. Soft swells, hard swells and leakers usually do represent microbial spoilage but can sometimes be caused by chemical reactions. As always, do not purchase or consume canned food products that are bulging or have packaging that appears compromised in any way. It's always better to be safe than sorry!
I have had a couple cans go bad in the past, and there is/was zero doubt that they were unsafe. Bulging to the point of being explosive, bad odor when opened (a few I simply buried whole).
You cannot be too careful!
I’ve had pretty good luck so far. Some cans I missed on rotation that were 6 years old. Still good. I have seen some swell in tomato sauce after 5 years.
I quit storing tomato based products for longer periods. Too acidy. Just won’t keep.
and sometimes you just have to throw caution to the wind
6 months should be a safe rotation. 3 months better.
I wonder if canned food would last longer if it was irradiated
Right. But the point being many things last well beyond their best if used by date.
A year or so ago, I used a can of tomato sauce that was about 5 years old.
There was a noticeable “shrinkage” of the product, it was about 3/4 of an inch down from the rim. I take that to mean that even in professionally canned products, they cannot practically seal it against a bit of water loss.
Smelled fine, cooked up fine, angel hair pasta and garlic bread, some olives, it was a feast!
I was always under the impression that tomato products were, in general, too acid to have botulism.
But acidity by itself is not enough of an indicator. I had a can of mandarin oranges start to swell, so those got pitched.
Of course not all food contamination is necessarily botulism.
The problem with botulism is it doesn’t smell bad or taste bad, and cooking won’t neutralize the poison it produces.
I worked for a major hotel chain and it was a firing offense to buy mushrooms canned in China. Those are the most likely to have botulism.... both because the mushrooms are not acid, and because the chinese don’t have the same standards we have for canning.
It would. But they would have to bury you 12 feet deep to somewhat dim your inner glow...
Just kidding. They have been doing it for years.
So basically, if the can looks or acts like A. Weiner, throw it away.
Right. I pitch anything that doesn’t look right. I just made 12 pints of nanking cherry jelly and 8 quarts of syrup.
A few years ago I had several cans that showed bulging. Strangely, one was large can of sliced apples and another was a can of apple pie filling.
I toss any bulging cans.
A couple of days ago I was making a cheeseburger and for some reason got a whiff of the Kraft Mayonnaise. It had just a bit of spoiled smell. Not that bad but just enough I was suspicious.
I looked at the use by date and it was a few months past it. That really surprised me as my refrigerator is right about 34 degrees. As luck would have it, I had just bought another jar as this one was getting towards empty.
I looked at the date on the new one and it was only good for about 7 more months. I will have to start checking closer.
Watch out buttulinum - bad meat in the can.
Food in the fridge is generally safe - but not always.
Most bacteria go into almost a suspended animation at that temp, if not just outright croak.
Listeria isn’t one of those! Listeria is happy as a clam at temps of 40 degrees or less!
AFAIK, listeria is almost never fatal. But it might make you wish U wur dead!
Boiling for 10 minutes will inactivate the botulin toxin. At higher elevations, I would use a pressure cooker to make sure the heat is sufficient to kill the toxin.
Home canned non-acidic foods (like beans or meat) should *always* be cooked as if they are contaminated with C. botulinum.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.