The Canadian food company behind the massive Listeria-related recall of sunflower kernels that has led to secondary recalls of dozens of snack products from the likes of Planters, Kellogg, Nature Valley and Trader Joe’s is shuffling executives in an effort to clean up operations and prepare the company for possible sale. Top leaders of SunOpta Inc. of Toronto, Ontario, referred to the reassignment of quality assurance functions to Jim Gratzek, senior vice president for research and development, as part of their work to accelerate growth and enhance shareholder value.