Thanks very much. I am going to do the "milk going off" test with heat/cinnulin/syrup to see if the germ-suppressing power is approximately the same as each other.
I'm pretty sure that the cinnulin will fail, and probably the sugar reduced version also. The problem is that the fat in the milk coats the silver particles, it becomes a capping agent.
The old myth is that the settlers put a silver coin in their milk jugs to keep their milk fresh. That might have worked then, but milk today is not the same as milk was then. Today, its homogenized. The fat in the milk never separates from the water. Fat is a stabilizer which will coat the silver particles because silver is hydroscopic; it hates water.
Again, this is not a problem for CS when ingested because the stomach enzymes and acid strips any capping agent from the silver particles, but how to test it?