PREPARATION:

1. Combine sugar, water and salt in 2-quart pan. Cook, stirring occasionally, over medium heat until sugar is dissolved. Let cool. Stir in grapefruit juice and orange peel. Pour into 2 divided ice cube trays; freeze 2 hours or until almost firm. Transfer cubes to blender or food processor container fitted with metal blade or large bowl of electric mixer; process until smooth and slushy. Spoon into 1-quart container with lid. Cover and freeze until firm, about 3 hours or up to 2 weeks. Let stand at room temperature 10 minutes or until slightly softened before serving. Garnish with mint sprigs.