Of the major classes of food additives, preservatives are the ones that really get people animated. It’s understandable, since preservatives tend to have very science-y sounding names. But not all of them are the products of labs, and even among those that are, most are synthesized versions of chemicals that occur naturally (usually in plants). Are some to be avoided? Probably. Nitrates (found mostly in deli meats) leap to mind, since they can react with certain amino acids to create carcinogens called nitrosamines. On the other hand they kill botulism spores, which, you know, is a good thing. A few of them every now and again are certainly not going to hurt you.
Of course there are all sorts of common food ingredients that act as preservatives. Salt, that’s an easy one. Sugar, it does a great job of preserving fruit. Fat is another preservative that can work wonders in things like confit. And then there’s vinegar for pickling and alcohol for, well, also pickling. Smoke is a preservative, as is cold. Heat too, now that I think about it.
What do all these things have in common? They all either kill microbes or severely limit their ability to grow and multiply. These days, antimicrobials are just one of three main categories of preservatives, but I’ll need separate posts to talk about them all.