All the breads you mentioned most likely have the same or very similar preservatives. Common preservatives used in bread are: Calcium Propionate (and other Propionates such as Sodium or Potassium Propionate though Potassium Propionate is not allowed in Canada) and maybe Sodium Metabisulphate. The raisins probably have some Sulfer Dioxide as a preservative. You'll have to read the list of ingredients on the bread bag to look for these. A nice review of preservatives can be found at the American Chemical Society's magazine.
making a small donation to science.ca.