My guess as to why they also add HFCS is because, in addition to being a sweetener, it has a thickening effect. So a soup can be “thick and creamy” – which is usually an effect of slow-cooking for many hours – without actually having been cooked that long – if they’ve added a “thickening agent” like high-fructose corn syrup.
Also, high-fructose corn syrup is a very effective preservative. So, with the FDA’s proclomation that it cannot be said that high-fructose corn syrup is not natural (notice they didn’t go so far as to actually call it “natural”), a product can be labelled as being “all natural, with no preservatives.” Which seems deceptive from my perspective.
So those two reasons – thickening the soup and its use as a preservative – are the reasons I think some “food” companies put high-fructose corn syrup in soup.
~Sherry – Your No High-Fructose Corn Syrup Blogger