The FDA requires the same standards of production, ingredients and storage for generic versions of staples like flour, sugar, salt and spices. Obscure details of production aside, it's almost impossible to find a difference beyond labeling for these products [source: The Simple Dollar].
Salt, for example, is a simple chemical compound. Beyond the usual added iodine, it's hard to mess with that recipe! Of course, the variations in price can be astounding: An ounce of name-brand oregano, for example, can sell for almost four times as much as the generic, and the only difference is the name on the label.
Plus, if you've ever dropped a bag of sugar or flour in the kitchen, or opened one up to find surprise visitors, you know the first thing to do when you get home is transfer it to your own containers. And that company label you just paid so much for? It goes out with the recycling.
Likewise, produce and precut salad mix are two more categories where corporate origin has much less to do with quality or freshness. In fact, it's a good idea to ignore those little brand-name stickers altogether and go with your eyes and nose. Otherwise, you'll end up paying for the sticker, with no difference in quality at all.