Colorado State University Cooperative Extension
SafeFood Rapid Response Network
SAFEFOOD NEWS - Summer 2001 - Vol 5, No. 4
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Commercially Canned Food: FAQ's
Most consumers know the visual "red flags" that alert them to a potential food safety concern when looking at the exterior of a commercially canned food. For example bulging ends are cause for concern as are any signs of a leaking seal. But what about cans that "hiss" or "spurt liquid" when they're opened? Can these conditions be explained by the higher altitude of Colorado, or is it an unwanted organism?
The Canned Food Alliance (CFA), which is a consortium of steelmakers, canmakers, food processors, and canned food brands, can help answer these questions and more. Below is a list of Frequently Asked Questions (FAQ's) about canned foods and can be found on the CFA's website.
Q. Do canned foods have expiration dates?
A. Many canned products now have a "for best quality use by" date stamped on the top or bottom of the can. "Expiration" dates are rarely found on canned food.
Q. How long does canned food remain edible and retain its nutritional content after it is purchased?
A. Canned food has a shelf life of at least two years from the date of processing. Canned food retains its safety and nutritional value well beyond two years, but it may have some variation in quality, such as a change in color and texture.
Q. How long is it between the date of processing and the date of purchase? How can I find out the exact date of processing?
A. In a well-run supermarket, foods on the shelf will be rotated on a regular basis, so there is continuous turnover. However, if you want to learn the date a particular product was packed, some food companies use a series of numbers or letters that may contain a date. To "break the code," call the toll-free number or write to the address on the product. According to one manufacturer, its product code of 81382 indicates it was packed in 1998 (the first number, eight, is the year), on the 138th day (middle three numbers), by the second shift (the last number is two). The codes may differ from one processor to another. To be certain, call the company.
Q. Are canned foods safe?
A. Yes. Research shows that the commercial canning process not only destroys bacteria that can cause food spoilage, but also can eliminate as much as 99% of the pesticide residues occasionally found in fresh produce.
Q. Can canned foods be heated in their containers?
A. Yes. If it is necessary to heat canned foods in the container, the top must be removed to prevent pressure build-up.
Q. Does damage to the outside of the can indicate damage to the food?
A. Not necessarily, but some good judgment should be used. Rust or dents do not affect the contents of the can as long as the can does not leak. If the can is leaking, however, or if the ends are bulged, the food should not be used. These containers should be returned unopened to the place of purchase.
Q. Can you refrigerate canned foods after use?
A. Yes. Unused portions of canned foods can be refrigerated after use, but should be removed from the can and placed in storage containers first, to avoid development of off-flavoring.
Q. Should cans "hiss" when they're opened?
A. Some cans may hiss because they are vacuum-packed and the noise is a result of air pressure, which is perfectly normal. However, if a can hisses loudly or spurts when opened, it may be an indication that the food is spoiled.
Visit the CFA website for additional information on commercially canned foods: www.mealtime.org.
Source: Canned Food Alliance-About Canned Food. www.mealtime.org/about/faq.htm
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