I use Hangsens Menthol Sensation. Does the trick for me.
And at the risk of being hung drawn and quartered, I slung a couple of drops of it into Mrs Lords Kendall Mint Cake the other day, just the once, just to see.......
If you've got some fruit juice you'd like to make menthol, pop down to boots and buy some menthol crystals and drop A very very small amount into your juice. A little goes a very long way so go easy.