Beware of cans

Do not store canned fruits and vegetables in open cans

10/21/2011

Tin cans often release metal residues to the contents after opening. The contained canned fruits or vegetables should therefore either be eaten after opening or immediately transferred to another vessel, the German Association of Food Chemists in the Public Service (BLC) warns in a recent release.

On the storage of canned fruit and Co. in the cans, is to dispense after opening the canned food urgently, said Detmar Lehmann BLC. Because under oxygen supply, ingredients of the packaging begin to dissolve and go over to the content. The canned fruits often taste slightly metallic, for example because tin is released from the can wall. While many preserves have a protective coating inside (such as plastic) to prevent material diffusion, can openers and forks can damage the coating. Therefore, the contents should be removed immediately after opening the can - a storage of canned fruits and Co. in open canned food is urgently to be avoided, explained the experts of the BLC.

Eat or top up can contents
According to the food chemist, the food cans sometimes do not even have a corresponding protective coating. Because consumers have become so used to the metal taste of canned fruits and vegetables that manufacturers do not have to worry about complaints if they omit the protective coating, explained the BLC. Whether the protective lacquer is missing, consumers recognize it, „that the tin looks marbled from the inside“, emphasized Detmar Lehmann. The lack of protective coating, however, according to the experts, no problem as long as the canned food is closed. Because until then stay „the can is a closed system, between the can wall and the liquid there is a kind of balance“, explained Detmar Lehmann. However, as soon as the cans are opened and oxygen enters, the system becomes unbalanced and the metallic can wall releases tin to the contents. Therefore, consumers should take the canned fruits and vegetables directly after opening „either eat or transfer“, stressed Lehmann.

Health risk due to food cans?
If the food remains in the cans even after opening, various materials from the can wall can be transferred to the contents. In particular, the potential burden of canned fruits with tin is a health risk that should not be underestimated. Although tin is generally considered to be non-toxic, the uptake in large quantities contaminates the kidneys and can cause long-term significant health problems, said the expert of the BLC. The food chemists also warn against the consumption of canned contents, if the food cans already have a bulging lids. Because in such cases there is a risk that the preservation was not performed properly and there is a potential threat of life-threatening poisoning in the form of botulism. (Fp)

Image: Andreas Stix