That's not even tasting a bit fizzy. In the eighties I remember someone eating a tin of Scott's or Shackleton's bully beef on the telly and it was fine. Fair doos, it'd been in Antarctica for nigh on a century.
Just check to see if the tins are blown at each end then get a trust "friend" to sample. They say that the tinned foods caused The Ross expedition in HMS Eribus to fail in the North West Passage search