"Captain Cool" wrote in :

Dear Group,

I love a good tuna salad sandwich and a cold beer. I make tuna salad
by combining one can of solid albacore with a diced Spanish onion,
diced dill pickle, Mrs. Dash seasoning, white pepper, lemon or lime
juice and mayonnaise. I mix it all up and apply a liberal coating to
freshly baked Bahamian bread and enjoy a meal fit for a king.


Being a live aboard sailor with no refrigeration, I sometimes wonder
about the mayonnaise. I hear people say that one can get terribly ill
by eating non-refrigerated mayonnaise. Perhaps that is an old wives
tale. Why do I say this? Well, as an experiment I took a new 16 oz.
bottle of Deep South Real Mayonnaise, scooped out a couple heaping
tablespoons and used it to make tuna salad. I then put the lid back on
and stowed the bottle back in the settee locker. Six months later, I
used the contents of the same bottle to make another batch of tuna
salad. It had somewhat of a strong taste, but I did not get sick.
From this I would conclude that real mayonnaise lasts almost forever.
I would like to hear from anyone with similar or opposing experiences.

Will mayonnaise make you sick if you leave the picnic potato salad out too
long in this heat?

Dr. Doyle: There's an old wives' tale that mayonnaise being added to
perishable foods will cause food poisoning. That's not true. Acid is added
to mayonnaise to prevent these bad bacteria from growing and producing
illness. However, there are certain types of micorganisms -- such as molds
and other types of bacteria -- that can spoil mayonnaise. [They] don't make
you sick, but they can spoil mayonnaise. So once mayonnaise has been opened,
it's important to refrigerate it so that the spoilage bacteria don't grow
and cause "off flavors."

Source: http://www.npr.org/templates/story/story.php?storyId=5639903