originally posted by Jonathan Loesberg:
As I said, my book, not in my office so I can't cite, on cooking chemistry for bozos, maintains that the emulsifiers in oil do allow marinades to penetrate meat. Even if that were a fraction of an inch, in a boned and butterflied leg, that would be more than sufficient to affect flavor. It wouldn't do much to tenderize, though. With regard to that, I can only testify that it does seem to help with Aussie and NZ lamb, which I find gamier (good) and tougher (bad) than US lamb.