บทคัดย่องานวิจัย

หมวดหมู่ : ฐานข้อมูลงานวิจัย

Effect of 1-MCP on avocado quality in relation to membrane integrity, polyphenol oxidase and peroxidase activity.

Hershkovitz V., Feygenberg O., Ben Arie R., Saguy I.S., Pesis E.

5th International Postharvest Symposium . Volume of Abstract . Verona, Italy 6-11 June 2004. 143 p.

2004

บทคัดย่อ

Effect of 1-MCP on avocado quality in relation to membrane integrity, polyphenol oxidase and peroxidase activity.  Ripening of Fuete, Pinkerton and Hass avocado cultivars was significantly inhibited by 1-methylcyclopropene (1-MCP).Application of 1-MCP at low concentrations (150-300 ppb; for 18 h at 20 °C) prior to the climacteric peak, was effective in reducing both CO2 and ethylene production, as well as decreasing fruit softening and electrical conductivity (EC) measurements.The EC measurement carried out using a special probe that penetrated the intact fruit was found as a good indicator for predicting and expressing membrane integrity.

Avocado treated with 1-MCP before storing for 4 weeks at 5 °C, resulted in reduced chilling injury symptoms expressed as mesocarp discoloration, and a decreased polyphenol oxidase (PPO) and peroxidase (POD) activity.Both PPO and POD activity that initially were quite low in the freshly harvested fruit, increased significantly during the cold storage and thereafter its removal to ambient temperature simulating commercial shelf life conditions.Ethylene action inhibited by 1-MCP, probably prevented the disruption of the cell membranes, which reduced the contact of the PPO enzyme with the phenolic substrates, resulting in a lesser amount of pulpbrowning.

Chilling injury symptoms in the avocado fruit expressed as mesocarp discoloration was found to be correlative with higher EC values.The highest EC values were found in the brown tissue of the midsection part close to the seed, while the lowest EC values were found in the green tissue close to the peel.The data highlight that 1-MCP could be utilized to keep quality of avocado during cold storage and shelf life by reducing ethylene levels, decreasing the oxidative activity, maintaining membrane integrity and inhibition of chilling injury symptoms.