The only solution I know of is that every time your cat tries to take something with a different mint from you, like your tea or some gum is to give the cat some dried
catnip.
Of course, I say that with confidence only because my cat seems to only want
catnip on occasion and not everyday. If I offer her catnip when she isn't really interested, she ignores the offer. So, you could try this. I think I would put my purse in a different location, though, just to be on the safe side.