Step 1: Understand food preservatives.
Food preservatives are substances that prevent spoilage of food by inhibiting the growth of microorganisms. Step 2: Analyze each option. (A) Alitame: It is an artificial sweetener and not used as a food preservative. (B) Sodium benzoate: Commonly used as a food preservative, especially in acidic foods. (C) Propionic acid salts: Used as preservatives to prevent mold growth in bread and bakery products. (D) Sorbic acid salts: Widely used preservatives to inhibit fungal growth. Step 3: Conclusion.
Alitame is not used for food preservation.