The restaurant supply company is selling to dozens and hundreds of restaurants, so it is kind of like a fast food chain, just not under the same logo.
The restaurant needs twenty five-pound bags of prepared chicken every day. The supplier sources this chicken meat, spices, seasonings, and synthetic chemicals from a number of distributors, who source the components from a number of other suppliers, who eventually source them from the farms. The farms are producing for volume, so quality is not really in the picture, as long as it meets the inspection standards and government regulations.
It is not only the finished product, but also the sub-components, that spend days, months, sometimes years in the supply chain, being processed, preserved, and homogenized, and processed again.
Just like with software, you have to check and verify all the sources, or at least have someone do it for you. This may mean buying from the farmer's market, or going to the farm itself.
If you can't do that, you have to find a trustworthy supplier and take their word for it.