In a saucepan, combine cornstarch and lemon juice until smooth. Add the preserves and cinnamon. Bring to a boil over medium heat; cook and stir for 2 minutes or until thickened. Add sausage and pineapple; stir to coat. Cook for 5 minutes or until heated through. Just before serving, stir in oranges and apple. Serve warm. Refrigerate any leftovers.