Preheat oven to 350°F. Paper-line or grease 30 muffin cups.
Combine flour, pumpkin pie spice, baking soda and salt in a large bowl
Combine sugar, pumpkin, eggs, oil and juice in large mixer bowl; beat just until blended. Add apples. Add flour mixture; stir just until moistened. Spoon batter into prepared muffin cups, filling ¾ full.
Bake for 25 to 30 minutes or until wooden pick inserted in centers comes out clean. Cool in pans on wire rack for 10 minutes; remove to wire rack to cool completely. Store muffins in covered container or resealable plastic bags.