Place preserves in a small saucepan over medium-low heat; cook 10 minutes or until melted. Keep warm over low heat.
Combine the salt, oregano, garlic powder, and pepper; rub evenly over pork. Place pork on a rack coated with cooking spray; place rack in a shallow roasting pan. Bake at 425' for 30 minutes. Brush 1/4 cup preserves evenly over pork. Bake an additional 10 minutes. Brush remaining preserves evenly over the pork. Bake an additional 10 minutes or until meat thermometer registers 155' (slight pink). Let stand 10 minutes before slicing.