DAKOTA DUNES, S.D. (AP) — A South Dakota beef company says it plans to close processing plants in three states because of the controversy surrounding a product that critics have dubbed "pink slime." Beef Products Incorporated spokesman Rich Jochum said Monday that 650 jobs will be lost when it closes its plants in Garden City, Kan.; Amarillo, Texas; and Waterloo, Iowa. The closures will be effective May 25. A plant in South Sioux City, Neb., will remain open. The company blames what it calls unfounded attacks over a product that it calls "lean, finely textured beef." In the process, bits of beef are heated and treated with a small amount of ammonia. Beef Products is based in Dakota Dunes, S.D.