Umami aside ("just because you don't believe in Father Christmas doesn't mean that he doesn't exist !"). one thing that I regularly notice about commercial food (Fray Bentos steak-and-kidney pies, Waitrose beef-and-pearl-barley, ...) is that it contains detectable (some might say "excessive") levels of sweetness/sugar content, whereas the home-made equivalent rarely if ever does. Would this also be your experience, Bob ?
** Phil.