McKee Foods, Collegedale, TN, adds to its product line Little Debbie single-serve premium muffins. The muffins, available in the two most popular flavors for convenience store shoppers — banana nut and blueberry — will be available on shelves in September. Muffins are a $155 million segment of the baked sweet goods category in convenience stores, and McKee is focusing on the on-the-go segment of those shoppers.