Sherlock Holmes ... he could smell or taste anything and know instantly what it was and it's origin! And, I would have to say that only second to the most honorable Mr. Holmes would be the American, Derek Flint - who also exhibited the same capabilities.
But, I have to go with Robo - if you're talking contemporary real people - Anthony Bourdain for prepared dishes, Pete Luckett - "The Food Hunter" or the "Traveling Green Grocer" as he is sometimes called who really knows his fresh fruits and vegetables, and who could ignore Rachel Ray with her $40-a-day and her soda fountain trained culinary pallet?
"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain