Effects of exogenous propylene and fruit calcium on ripening of non-chilled and chilled Anjou pears
Dimitrios Gerasopoulos and Daryl G. Richardson
Postharvest Biology and Technology Vol: 8 Issue: 2 Pages: 111-120
1996
บทคัดย่อ
In order to establish the interactions of calcium sprays and exogenous propylene
on the ripening of Anjou pears when either freshly harvested or chilled for 115
days, 2 levels of CaCl2 preharvest sprays and 2 levels of propylene
(an ethylene analogue) were used postharvest. Freshly harvested fruits failed
to ripen in air, while 50 l/l
propylene during ripening stimulated softening in all cases but failed to
trigger any ethylene synthesis and resulted in a slow increase in respiration
over a 30-day period. Treatment with 500
l/l
propylene during ripening first accelerated softening, then initiated ethylene
and CO2 production. Fully chilled fruit (115 days at -1°C)
when returned to ambient temperature ripened satisfactorily within 8 days
regardless of the propylene treatment. Ethylene amounts produced after the
chilling requirement was satisfied, were three-fold that produced at harvest.
Calcium uptake was significant only when high concentrations were applied, but
even this had only slight effects on ripening behavior. Although the controls
and calcium treated fruits had the same firmness at harvest, the high Ca fruits
showed consistently better firmness retention and slower increase in internal
ethylene.