It is no secret that potatoes are a great source of potassium, according to Don Flannery, executive director of the Maine Potato Board. For decades, industry officials have lauded the nutritional benefits of the state’s signature crop, which has just 110 calories in a medium potato, along with zero fat and 620 milligrams of potassium if eaten with the skin, according to the Maine Potato Board. Now the board is watching steps taken by the U.S. Food and Drug Administration in late May, when the agency updated nutritional information for most packaged foods sold in the United States. More