I'm wondering if the chemicals involved in the Belousov-Zhabotinsky reaction would be at all poisonous. If at all, do you know of another similar oscillating reaction that could safely be ingested?
[Edit] Seriously, I was wondering if it would be possible to invent a candy that changes flavors in waves. I know Turing came up with a mathematical demonstration of the possibility of this sort of reaction long before its discovery which makes me think that others exist.
Here is the apparent chemical reaction:
$$\ce{3CH2(CO2H)2 + 4BrO3- -> 4Br- + 9CO2 + 6H2O}$$