Glazed Yams

4 yams or sweet potatoes, peeled and sliced
1/2 cup brown sugar
1/4 cup butter or margarine
1/4 cup frozen pineapple juice concentrate
1 tablespoon lemon juice
ground cinnamon

Boil the yams in salted water for 20 to 25 minutes or until they are tender. Drain the yams, and arrange them in a large baking dish in a single layer. In a small saucepan, melt the butter, and add the concentrate and lemon juice. Heat until bubbly. Pour over the yams. Sprinkle with cinnamon. Cover the baking dish and bake at 300 F for an hour. Add orange juice or pineapple juice if necessary during baking.