Effect Of Phospholipase D Inhibitor Treatment On Postharvest Quality Maintenance Of Flat Peach Fruits

Different concentration of phospolipase D (PLD) inhibitors 1-hexanal and 1-hexanol were selected to study the effect on quality maintenance of flat peach fruits during storage period. The relationship of 1-hexanal and 1-hexanol to the quality-related, physiological characteristics and cellular ultrastructure of flat peach fruits were discussed. The results are as follows:1. PLD inhibitor treatments could maintain soluble solids content, titratable acidity and VC content of "Yingger" flat peach fruits during storage. Besides, these treatments could reduce the decay index and maintain relatively higher firmness of the fruits. Within these four treatments,0.1% hexanal treatment seems to be better than other treatments in maintaining the quality and flavor of the fruits. However, PLD inhibitor treatments had no significant effect either on delaying the peak time of the ethylene production or reducing the amount of ethylene production.2. PLD inhibitor treatments could increase the activities of active oxygen degradation enzymes such as SOD, CAT and APX, but decrease the activity of POD, which is good for maintaining the internal active oxygen balance of flat peach fruits. Besides, after using PLD inhibitors, the activities of the cell membrane degradation enzymes like PLD and LOX got reduced, which would be helpful in keeping the structure of the cell membrane. At the same time, these treatments also lowered the activities of cellulase and PME, but had no obvious effect onβ-Gal.3. The cellular ultrastructure of "Yingger" flat peach fruit showed completely the senescent characteristics after cold storage for 50 days. But the collapse of the cell wall structure, the reducing of the cell content and the breakdown of the cellular compartmentalization are much slower in PLD inhibitor-treated fruits. Within these treatments,0.1% hexanal was much better than other groups in keeping cell configuration and cell wall structure.The results indicate that it is possible to use PLD inhibitors hexanal and hexanol on postharvest storage of flat peach fruits. Though these treatments have different effects on the quality-related, physiological characteristics of the fruits, on the whole 0.1% hexanal treatment is better than other treatments. By using proper concentration, PLD inhibitor treatment helps quality maintenance of flat peach fruits after harvest.