Concentrating mixtures of volatile compounds
The simplest method would be fractional distillation: if you have a mixture of miscible liquids with different boiling points, as is the case in your question, then you can heat them slowly. When the boiling point of the most volatile compound in the mixture is reached, it begins to boil and the temperature does not increase until it has all boiled off. The vapour formed is cooled with a condenser and collected as a liquid. As soon as the temperature begins to increase again, all of this compound has evaporated, so it can be removed. Provided the boiling points aren't too close, you could use this to separate out all the compounds in the mixture. A diagram of the set-up (from Wikipedia) is below.



This would be easier with water than ethanol, since it has a higher boiling point so is less likely to boil at a similar temperature to your desired compound.
(The most common way to separate out mixtures in chemistry is chromatography - for example, HPLC or GC - but I'm not sure you'd want to put the results in food! HPLC, which stands for high performance liquid chromatography, involves the use of a solvent mixture which normally includes chemicals like acetonitrile or methanol, neither of which are safe to ingest.)