ant's experience probably points to the majority of snmx royalties being closer to 1% than 4%. It does sound like snmx has real deals and hard terms so I'm not concerned that this is bait and switch and the royalties will be far less.
Sounds like the promise of the tech is that even after paying a small royalty the mfg would be saving money by using less of offending ingredients. Whereas the same wouldn't necessarily be true of toothpaste? We're also at a time where there's great concern about the (un)healthy aspects of processed foods and drinks and in turn potential for competitive marketing advantages.
I think it's a pretty great thing if they (or anyone) can develop compounds to allow packaged food mfg to do things like cut fructose levels in soda (much debate about a link to climbing diabetes rates), cut sodium in canned soups (loaded with salt) and so forth without sacrificing taste. Recent wsj article about some sort of popular new artificial sweetener that's doing so well, the mfg can't keep up with demand. So there's no doubt there's a real market. I think this is worth keeping an eye on, esp as it's the only pure play.