Why should lettuce and leafy vegetables be separated from sources of ethylene gas?

• A. They are susceptible to undesirable respiration
• B. They produce ethylene themselves
• C. They will lose color quickly
• D. They become unsafe to eat

Answer: (A)

Leafy greens like lettuce are highly sensitive to ethylene gas, which acts as a ripening hormone and speeds up their metabolism. When exposed to ethylene, their respiration rate increases, causing faster breakdown of stored sugars and acids. This accelerates aging, leading to wilting, softening, yellowing, and overall quality decline. Keeping these greens away from ethylene sources slows this rapid deterioration and helps preserve freshness longer.

Other effects you might think of, like color changes or safety, are outcomes of the accelerated aging, not the primary reason for separation. And while some produce their own ethylene, the concern here is the impact of external ethylene on their quality, not their own gas production.