Spoilage in canned food products

Colorado State University Extension ^ | 2008 | Stephanie Hoffman

[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!

[ansel12]

You describe a huge drawback of the precision of modern manufacturing, there is no overbuild, no margin in many items and utensils and tools.

A manufacturer can be so precise, that he meets just exactly the point at where the minimum yet adequate meet, which of course means more failures and in almost all cases, less durability.

[Bloody Sam Roberts]

I always check the CVS store shelves of food items when waiting for a prescription. They occasionally have 1LB. Dak canned hams on sale for 2 for $5.00...half price (Thanks for the tip Kart!). I found them on sale this past week. However, all the cans were more or less “stuck” to the shelf because one can had leaked. I decided to pass on the whole lot rather than hunt down the leaker and assume I’d found the only one. As ‘they’ say, better safe than sorry.

[Bloody Sam Roberts]

and because the Chinese don’t have the same standards we have for canning.

Hey...there's a billion or more of them suckers over there. Why should Central Committee care if a few thousand serfs drop dead from food poisoning?

[djf]

I stocked up on the DAK hams a while back, got about 25 of them.

Good item to have. I imagine that barring the cans getting dented, or exposed to moisture, they will last quite a long time.

[Bloody Sam Roberts]

they will last quite a long time.That's what I'm thinking. Looks like a good number of years on the 'sell by' date. Which means only that you'll survive the experience. Not that it's a hard limit.