1-MCP Improves the Quality of Stored 'Wonderful' Pomegranates

A major limitation in pomegranate storage is the deterioration of internal quality and taste. As pomegranate is a non-climacteric fruit, not producing large amounts of ethylene during ripening, it is not expected to respond to 1-methylcyclopropene (1-MCP), an ethylene action inhibitor. However, there are reports that non-climacteric fruits may respond to this treatment and one of its effects may be the deceleration of respiration. Our hypothesis was that 1-MCP treatment of pomegranate could delay senescence and deterioration of fruit quality in storage by minimizing the effect of ethylene on metabolic processes, such as respiration. Both laboratory scale and commercial experiments were conducted to examine 1-MCP effects on quality attributes of stored 'Wonderful' pomegranates. The treatment was applied at 900 ppb for 24 h at 20 degrees C prior to storage at 7 degrees C in either air or a controlled atmosphere (2% O-2 + 5% CO2). Respiration in regular air (RA) was reduced in response to 1-MCP, but was similar to that of the control after controlled atmosphere (CA) storage. In addition, lower ethanol and acetaldehyde contents were measured in treated fruit. Exposure of fruit from both treatments to ethylene enhanced their respiration rates. Improved internal quality detected as a result of 1-MCP treatment, was expressed as an inhibition of browning of the internal white septa and preservation of aril color and taste during storage and subsequent shelf life. Although the effect of 1-MCP on external quality was not significant, the overall commercial quality of the pomegranates was improved due to some inhibition of husk scald, especially in air storage. Overall, 1-MCP treatment was shown to improve the quality of stored 'Wonderful' pomegranates, especially their internal quality and taste. We assume that this may be the result of delayed metabolic processes, expressed as reduced respiration and ethanol and acetaldehyde production.