Apple Cabbage Coleslaw

3 (16 ounce) cartons sour cream
1 cup granulated sugar
2 tablespoons salt
1 tablespoon pepper
5 teaspoons ground mustard
4 to 5 pounds unpeeled tart apples, cut into julienne strips
1/2 cup lemon juice
3 large heads cabbage (3 to 4 pounds each), shredded