Whole carrots (Daucus carotaL.) and midrib tissues of iceberg lettuce (Lactuca
sativa L.) were treated with 42 µmol·m–3
MCP, then exposed to ethylene. Exposure to
42 µmol·m–3
ethylene at 10 °C increased isocoumarin content ≈40-fold in both peel and pulp
of nontreated carrots within 4 days, but treatment with MCP for 4 hours at 20 °C before
exposure to ethylene prevented isocoumarin accumulation. Ethylene-induced acidity
loss and respiration rate increase in carrots were also prevented by MCP treatment.
Ethylene treatment (126 µmol·m–3
) of lettuce at 6 °C had induced russet spotting >5% to
10% of the midrib tissue by day 3 and 30% to 35% by day 9, while pretreatment with MCP
for 4 hours at 6 °C prevented development of russet spotting. The results indicate that
ethylene-induced physiological disorders and quality loss in carrots and iceberg lettuce
can be prevented by MCP treatment prior to exposure to ethylene. Chemical name used:
1-methylcyclopropene (MCP).