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.