Place pears in a food processor, and pulse until pureed (depending on the capacity of your processor, you may need to do this in batches). Add sugar, juice and salt. Pour mixture into a 9 x 13-inch (4-quart) baking dish. Add star anise. Bake for 3 hours or until thick, stirring every 30 minutes. Cool completely. (Mixture will continue to thicken as it cools.) Refrigerate up to 1 week.