Yeah, I've heard that a lot of the generic food is, essentially, the official brand stuff but repackaged, right down to coming from the same factories. Not all, but most.
So, if that's true... they're screwed! :lolface:
I don't know how true that is. You have to look at the label. Usually if something is manufactured by a major company for a retailer, it will say so on the label. Many supermarkets do own their own private-label brands, or have longstanding contracts/arrangements with lower-profile food producers.
At any rate, my family has been buying store-brand stuff for years, and most of the time, it's at least as good in quality as the higher-priced brand name stuff. It's a good way to save money.
There is a factory not to far from my college(relatively speaking) that produces garbage bags for hefty and Great Value(Wal-Mart's brand). There might be a few differences, but the product is pretty much the same, and the differences don't matter(Wal-Mart's seem a little on the small side). When it comes to food, I think your right though. Most companies care about their recipe and won't let it be branded as something else. If a store/private label does use food from another company, there will be a label of said second company somewhere clearly visible. Store label brands do tend to be pretty good in quality. Target has the best private label IMO, although Wal-Marts private label can be a little inconsistent when it comes to food quality(still worth the price though).
When I worked at Del Monte for a season many (many) moons ago, we would shut down the labeller and swap in the Aldi brand labels and the Jewel brand labels all the time. Usually, we did 3 runs per night, one for each label. They didn't switch the cans coming down the belt, just the labels.
No idea if it is still like this, but I imagine that it probably is.