Question

Which of the following chemical is used to delay the ripening ?

• A. Ethylene
• B. Ascorbic acid
• C. EDTA
• D. Auxins

Hint:

Ethylene accelerates ripening, whereas Auxins and Gibberellins act physiologically to delay senescence and fruit ripening.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Fruit ripening is a complex, genetically programmed physiological process governed by plant hormones (phytohormones).
Applying specific plant growth regulators can either accelerate or delay this ripening process to extend post-harvest shelf life.

Step 2: Detailed Explanation:
Let us analyze the physiological roles of the listed chemicals:
1. Ethylene (A): Known as the primary gaseous ripening hormone. It accelerates and coordinates the ripening process in climacteric fruits. Thus, it cannot be used to delay ripening.
2. Auxins (D): Auxins (such as indole-3-acetic acid or synthetic auxins like 2,4-dichlorophenoxyacetic acid) are known to act as inhibitors of senescence and ripening in several fruit species.
When applied exogenously to pre-climacteric fruits, auxins delay the onset of the ethylene burst and chlorophyll degradation, thereby significantly postponing the softening and ripening process.
For example, auxin sprays are used commercially on citrus fruits and bananas to delay peel color changes and senescence.
3. Ascorbic acid (B) & EDTA (C): These are food additives used primarily as antioxidants and chelating agents to prevent enzymatic browning and lipid oxidation, but they do not actively regulate plant hormone-mediated ripening pathways.

Step 3: Final Answer:
Thus, Auxins are used to delay the ripening of fruits.