Canned food safety?!
Canned food safety?
I am preparing for disasters, and have stocked up on some canned food, such as vegetables and meat products (e.g. chili, spam, mushrooms, etc.). Of course, most of these foods don't end up in my daily diet, so they stay in my pantry for a long time. Since my pantry isn't temperature controlled (perhaps over 85 degrees) and I don't use them often, I want to know how you can identify whether a can of food is unsafe, i.e. botulism. Some more details than "bulging ends." What do bulging ends even look like?! And storage over 1 year is not recommended, but it isn't likely will throw away food over the expiration date during times of emergency. Some explanation please!
Answers:
Two ways you can tell if your home-canned foods have been spoiled by bacteria.
1. An obvious color change. Many bacteria when in large numbers (colonies) present themselves in color. Some of these are white, red, yellow. In addition yeasts & molds can be black, brown, & white. The color change is an indication that the food is highly contaminated by a microorganism-do not eat it.
2. Bulge. A bulge is a sign of fermentation. The organism has produced carbon dioxide (CO2) or other gases and the food is likely spoiled. The most notorious bateria is Clostridium botulinum which produces a toxin that is deadly to humans. You can easily feel the bulge when you run your finger tips across the top of the tip. When a can is opened if it is foaming (not a bit of air foam) really noticable foam that is also a sign of fermentation by C. botulinum. Do not touch or taste or smell-throw it away. It is deadly!
Clostridium botulinum:
C. botulinum (botulism) is a gram-positive, anaerobic, rod-shaped, spore-forming bacteria. Originally, all organisms known to produce botulinm neurotoxin were included in the species.
The bacteria can be killed but the neurotoxin cannot be destroyed with normal practices. The occurance of C. botulinum is more often found in home canned foods than commercially produced foods.
One reason for the expiration date is due to things such a poor storage conditions. When the container warms & cools the seals can be weaken. The result may be contamination by microoganisms such as yeasts, molds, and bacteria. The worst being C. botulinum a toxin producing bacterium. Under good storage conditions a properly processed canned food should last longer than a year.