On the deli meats ...... the meats that come from the Deli and are sliced when you buy it, don't have the same levels of preservatives as those that are sliced and packaged individually (e.g., Oscar Meyer, Hormel, etc.).

In the Deli, once a package of bulk meat is opened and placed in the display case for slicing to order, it's not vacuum packed anymore so, its exposed to the air, supports bacterial and fungal growth and goes bad quicker.

So, yeah, if you're not going to eat it same day, get the prepackaged stuff in small quantities that stays vacuum packed until you serve it. It costs a bit more but stays fresh and good tasting longer.

In the small quantities that preservatives (usually nitrates/nitrites, bromates and sulfites) are in these packaged meats, they are not harmful. You can screen them though for those with the lowest quantities of these preservatives.

Bottom line, its a risk/benefit equation. A little salt compound preservatives in your system or stomach upset and diarrhea from spoiled meat.