Effect of 1-methylcyclopropane in combination with Calcium chloride on postharvest storage and quality of green olives

Green olive cultivars “Manzanila” and “Mission” were harvested at the mature green stage. They were either treated with 1-methylcyclopropane (1-MCP) at a concentration of 1.8 µL/L for 24 h at 20°C or kept untreated as a control. Both treated and untreated fruits were then immersed in water containing CaCl2 of 0 (control), 50 and 100 mM for 2 h under 1.2 bar pressure. Fruits were then surface dried, put into plastic basket and stored at 6°C with relative humidity of 80% in a refrigerator for 12 weeks. The non-1-MCP treated fruits softened within 6 weeks after harvest. In contrast, the 1-MCP treatment inhibited fruit softening and color changes. Treatment with CaCl2 delayed fruit softening, but had little effect on fruit color. The rate of ethylene production and respiration were also significantly (P<0.05) lower in fruits treated separately by 1-MCP and CaCl2, compared to the control. However, the effect of 1-MCP in combination with CaCl2 was more effective in the case of color change and softening during cold storage. It could be concluded that the fruits treated with a combination of 1-MCP and CaCl2, were superior in preventing fruit softening and green color loss, and suffered minimum damage for 12 weeks at 6°C.