Chemicals are added to food for (i) their preservation, (ii) enhancing their appeal, and (iii) adding nutritive value in them. Main categories
of food additives are as follows:

(i) Food colours

(ii) Flavours and sweeteners

(iii) Fat emulsifiers and stabilising agents

(iv) Flour improvers - antistaling agents and bleaches

(v) Antioxidants

(vi) Preservatives

(vii) Nutritional supplements such as minerals, vitamins and amino acids.

Except for chemicals of category (vii), none of the above additives have nutritive value. These are added either to increase the shelf life of
stored food or for cosmetic purposes.

Which of the following chemicals are added to increase the shelf-life of foods?

Antioxidants

The correct answer is option 4. Antioxidants.

Here is an explanation of why antioxidants are used to increase the shelf-life of foods and the roles of the other chemicals listed:

4. Antioxidants:

Antioxidants are substances that inhibit oxidation, a chemical reaction that can produce free radicals, leading to chain reactions that may damage the cells of organisms. In the context of food preservation, antioxidants prevent the oxidation of fats and oils, which can cause rancidity and spoilage.

Common Examples: Vitamin C (ascorbic acid), Vitamin E (tocopherols), butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT).

By preventing oxidation, antioxidants help maintain the quality, flavor, and nutritional value of food products for a longer period, thus extending their shelf-life.

1. Food Colour:

Food colorants are added to enhance or restore the color of food, making it more appealing to consumers. Food colorants do not have properties that inhibit spoilage or extend the shelf-life of food. Their primary role is cosmetic.

2. Sweeteners:

Sweeteners, both natural and artificial, are added to foods to provide a sweet taste. They can be used as sugar substitutes to reduce calories or provide sweetness to sugar-free products. Sweeteners do not directly contribute to extending the shelf-life of food products. Their purpose is to modify the taste.

3. Artificial Flavours:

Artificial flavors are chemicals designed to mimic natural flavors. They are used to enhance or impart specific flavors to food products. Artificial flavors do not have preservative properties. Their function is to improve or add to the flavor profile of the food.

In summary, while food color, sweeteners, and artificial flavors are added to foods for their sensory qualities, antioxidants are specifically used to increase the shelf-life by protecting the food from oxidative damage and spoilage.