The USA has Wal-Mart, France has Carrefour, and Korea has E-Mart.
You can walk around and eat some sample food. These stores also have several food sample stations set up, so you can try an unknown food before buying it. Snacks and food samples that a grocery store will serve at various locations in order to tempt the patrons into buying something they weren't planning on..
Go on, try it. :)