Using 1-MCP to inhibit the influence of ripening on impact properties of pear and apple tissue.
Baritelle, A. L., Hyde, G. M., Fellman, J. K. and Varith, J.
Postharvest Biology and Technology, Volume 23, Number 2, November 2001. pp. 153-160.
2001
บทคัดย่อ
This work is part of a larger effort to determine the effects of hydration on the impact failure properties (loading velocities >100 mm/s) bruise threshold of apple and pear tissue. Since time is required to dehydrate fruit slightly, and since ripening normally occurs during that time, it is desirable to arrest ripening during the dehydration process to minimize or eliminate ripening effects so that hydration effects can be determined. This experiment used 1-methylcyclopropene (1-MCP) to arrest ripening, and then tested whether 1-MCP affected impact failure properties. Thirty fruit from each of four apple cultivars (Fuji, Red Delicious, Golden Delicious and Rome) and two pear cultivars (Bartlett and D'Anjou) were randomly assigned to one of three treatments. The 'fresh' treatment fruit were tested immediately using the procedure described below. The second group was treated with 2 ppm of 1-MCP for 16 h, and the last group was left untreated as a control. The 1-MCP treated samples and the control samples were stored at room temperature in 98+% RH chambers (to minimize moisture loss) for 10 days and then mass losses were measured and tissue samples were subjected to dynamic axial compression (DAC). Six cylindrical tissue samples from each fruit were loaded to failure (strain rate 80/s) at room temperature (approx equal to 23 deg C) to determine tissue failure stress, failure strain and shock wave speed. Magness-Taylor (MT) force measurements were made on the same fruit immediately prior to the DAC testing. The MT values showed no significant difference between fresh (control) fruit at time 0 and 1-MCP treated fruit after 10 days at room temperature, except for the Bartlett pears, which ripened and softened over the 10 days. Untreated fruit all showed significantly lower MT forces after 10 days, except for the Fuji apples. DAC measurements showed significant changes in most of the mechanical properties with treatment, but these changes were consistent with the mass loss and corresponding slight dehydration in these fruit. While this work did not conclusively show that 1-MCP stopped the ripening process completely, it did show that smaller changes in the tissue mechanical properties occurred for the treated than for the untreated samples.