Preheat oven to 425 degrees F. Lightly coat a medium baking dish with nonstick cooking spray.
Transfer the roasted beet wedges to the baking dish.
In a medium bowl, whisk together the orange juice, balsamic vinegar, maple syrup, 1 teaspoon of the orange zest, and the mustard. Pour over the beets and gently toss to coat.
Roast in the oven, uncovered, for 15 minutes or until heated through and most of the liquid has absorbed.
Sprinkle with the remaining orange zest and some mint, if desired. Season with a little salt and pepper and serve.