Soak gelatin in 1/4 cup cold water.

Add lemon rind to another 1 1/2 cups water; bring to a boil and simmer gently for 5 minutes.

Strain, then measure only 1 cup to use; add gelatin mixture, lemon juice, sweetener, food color, and lemon extract, mix well. Chill until the consistency of unbeaten egg whites.

Fold carefully into yogurt; then fold in diced apples, celery, and walnuts. Mix carefully but well. Turn into a 2 1/2-cup salad mold or into five 1/2-cup molds. Cover and chill until firmly set. Serve as a salad on crisp lettuce.

This recipe yields 5 servings. Serving size: 1/2 cup.

Exchanges Per Serving: 1/2 Low-fat Milk.

Nutrition Facts: Carbohydrates 9g; Protein 5g; Fat 2g; Calories 68; Fiber 1.0g; Sodium 45mg; Cholesterol 1mg.

Note: Low-sodium diets: This recipe is excellent.