ma ‧ ven /ˈmeɪv ə n/ BrE AmE noun [countable]
[ Date: 1900-2000 ; Language: Yiddish ; Origin: meyvn , from Hebrew l'havin 'to understand' ]
American English someone who knows a lot about a particular subject
food/fashion/sports etc maven
A food maven could also be called a gourmet.