Place sweet potatoes in a Dutch oven. Stir together orange juice concentrate and next 4 ingredients in a small bowl. Pour over sweet potatoes, tossing to coat.
Cover and cook on low heat for 5 1/2 to 6 hours or until potatoes are tender.
Transfer potatoes to a serving dish using a slotted spoon. Increase heat to medium-high. Whisk together cornstarch and 1 Tbsp. cold water until smooth. Whisk cornstarch mixture into cooking liquid in Dutch oven. Cook, whisking constantly, 3 to 5 minutes or until sauce thickens. Spoon sauce over potatoes.
Stir together parsley, orange zest, and garlic. Sprinkle potatoes with parsley mixture and crumbled bacon.