Sam's Club stores are limiting the amount of rice customers can purchase. The warehouse club store is limiting the sale of jasmine, basmati and long-grain white rices to four bags per customer per visit. The limits are because of increases in the worldwide demand issues for rice and concerns over worldwide food shortages. Sam's Club says it's working with its suppliers to make sure rice products remain in-stock. On Wednesday, Costco announced purchase limits on rice and flour at some of its stores.