Question

Antioxidant which is obtained from a desert plant and shows synergistic action with citric acid is:

• A. Maleic acid
• B. BHA
• C. Tocopherols
• D. Nordihydroguaiaretic acid (NDGA)

Hint:

NDGA is a potent antioxidant from desert plants that works effectively in combination with other compounds like citric acid to inhibit oxidation.

Answer 1

The Correct Option is D

Nordihydroguaiaretic acid (NDGA) is an antioxidant obtained from a desert plant, commonly the creosote bush. It is known for its ability to show synergistic action with citric acid in enhancing its antioxidant properties, thereby preventing oxidation in various applications.

Answer 2

The question is looking for a natural antioxidant sourced from a desert plant that works synergistically with citric acid. Let's evaluate the four options.

1. Maleic acid: Maleic acid is a small synthetic dicarboxylic acid used mainly as an acidulant and chelating aid, not as an antioxidant, and it has no particular desert-plant origin.
2. BHA: Butylated hydroxyanisole is a widely used synthetic phenolic antioxidant manufactured industrially; it is not extracted from any plant, desert or otherwise.
3. Tocopherols: Tocopherols, the vitamin E family, are natural antioxidants but they are obtained mainly from vegetable oils such as soybean, sunflower, and wheat germ oil, not from a desert plant.
4. Nordihydroguaiaretic acid (NDGA): NDGA is extracted from the creosote bush (Larrea tridentata), a shrub that grows in arid desert regions of North America. It is a potent lipid-soluble antioxidant, and it is well documented to show a synergistic boost in antioxidant power when combined with citric acid, since citric acid chelates trace metal ions that would otherwise catalyse oxidation, complementing NDGA's own free-radical scavenging action.

Only NDGA matches both requirements at once, a desert-plant source and demonstrated synergism with citric acid.

Therefore, the correct answer is Nordihydroguaiaretic acid (NDGA).