Wegmans Food Markets says 4,000 pounds of its mashed sweet potatoes are being recalled because of possible contamination with pieces of white plastic. The Rochester, N.Y.-based grocery chain says the sweet potatoes packaged in 24 oz. plastic trays were sold between Sept. 22 and Nov. 9 in dairy departments at its stores in New York, Pennsylvania, New Jersey, Virginia, Maryland, and Massachusetts. They were recalled by supplier Orval Kent Foods of Wheeling, Ill.