swollen can will damage the tin coating on the can, cause the
can to rust, as rust is poisonous, we might get poisioned
aluminium will cause aluminium oxide with air, but the citric
acid in fruit will cause the aluminium oxide to dissolve and thus
exposed the aluminium for water in fruits to add on it, causing the
fruit can to dissolve ......
Thats more for dents since a can won't swell on its own but
dents can happen due to mishandling.
Regarding the Al cans, i forgot about the citric acid part but i
would really wonder whether citric acid is strong enough an acid to
dissolve Al2O3 since its a very weak acid.