Answer:
The scientist won't be able to find the product in the brain as this is due to the fact that the experience of tasting chocolate is restricted to the mind making it unnoticeable by anyone-after opening the skull and observing it.
Experience are locked to the mind just the way the brain is locked to the skull. It is possible to open the skull and observe it but it is not feasible to cut the mind open and observe it in that same fashion.
Let's say the scientist went further to lick the brain while you eating the chocolate. He will more that the brain does not taste like chocolate and if it does he can't get the actual experience the individual derive from his own mind as the experience and mental state is not equal to the physical state of the brain indicating more to a person than brain and nervous system as it as to do with one assessment on subjective facts.
The possible conclusion is there is a soul attached to the body which allows for interaction explaining further that man is made up of two distinct things which are a complex physical organism and a wholly mental soul (dualism). Thus, facts on conscious experience are typically subjective and can wholly be judged from the first-person perspective on the conscious topic (Thomas Nagel (1937-)).