Why do some fruits ripen after picking?
Show answer & explanation
Answer: Ethylene gas triggers ripening
Heat from transport speeds ripening — Wrong. Heat can accelerate ripening, but fruits ripen off the vine because they produce ethylene gas, a natural ripening hormone.
Ethylene gas triggers ripening ✓ — Correct! Climacteric fruits (tomatoes, bananas, avocados) produce ethylene gas, which triggers ripening even after harvest. Ethylene signals enzymes to break down cell walls (softening), convert starches to sugars (sweetening), and change colors. That's why putting unripe fruit with ripe bananas speeds ripening—ethylene spreads! Non-climacteric fruits (citrus, berries) don't ripen further after picking.
Bacteria cause fruit softening — Wrong. Ripening is a controlled plant hormone process involving ethylene, not bacterial decay. Bacteria cause rotting, which comes after ripening.