Study On The Effects Of Ethephon And 1-MCP For The Cuticular Wax Of Fragrant Pear And Its Relationship With Storage

In this study,fragrant pear was used as a test material.Changes in storage quality and physiological indicator of fragrant pear treated with different concentrations of ethephon and 1-MCP during refrigeration were measured.During the process of exogenous ethylene accelerate the ripening of fragrant pear and the process of 1-MCP inhibit the ripening of fragrant pear,effects on the wax content,wax composition and wax ultrastructure were analyzed.And by analyzing the correlation between wax changes and storage and physiological changes,to provide a basis for exploring the mechanism of the effect of cuticular wax on the storage and freshness of fragrant pear,and further clarify the role of ethylene in the regulation of cuticular wax components during the cold storage of fragrant pear.The important findings are as follows:(1)The effect of ethephon treatment on extract content,relative component content and ultrastructure of fragrant pear wax.Ethephon treatment increased the peak of total wax extraction content,reduced the relative alkane content and increased the relative aldehyde content,inhibited the decrease of the relative content of saturated fatty acid,enoic acid and ester,and the effect of 1g /L ethephon was outstanding.1 g/L ethephon promoted the increase of the relative content of alcohol,while 0.25 and 0.5 g/L ethephon treatment suppressed the increase of the relative content of alcohol.1 g/L ethephon accelerated the ultrastructural change of the wax surface of fragrant pear,dissolved and melted the wax crystals,and made the wax surface more complete and smoother.The above results indicated that ethephon treatment accelerated the change of epidermal wax extract content,relative content of components and ultrastructure of fragrant pear.(2)Ethephon treatment increased the respiratory rate at 40 d of storage and the amount of ethylene released at 60 d of storage,and advanced the peak of respiratory rate and ethylene release,improved the activity of PG and CX,promoted the reduction of firmness and total phenol content,and suppressed the decrease of TA content,increased SSC peak value,with 1 g/L ethephon prominent.And 0.25 and 1 g/L ethephon promoted cellulose degradation.It can be seen from the correlation analysis that 1 g/L ethephon may promote the downward trend of firmness by accelerating the decrease of the relative content of alkanes;may promote the upward trend of PG vitality by accelerating the increase of the relative content of alcohol;may promote the decline trend of cellulose content by delaying the decrease of the relative content of saturated fatty acids and enoic acid;it was possible to promote the upward trend of WSP content and the downward trend of hardness by delaying the decrease of the relative content of enoic acid.The above results indicated that ethephon accelerated the change of the epidermal wax content and the relative content of components during the process of promoting ripening of fragrant pear.(3)Effects of 1-MCP treatment on extract content,relative component content and ultrastructure of fragrant pear wax.The 1-MCP treatment inhibited the change of the extract content and the relative content of alkane and aldehyde in the wax,reduced the peak of the relative content of them.It also suppressed the increase in the relative content of alcohol and the decrease in the relative content of saturated fatty acid,enoic acid and ester.And the inhibitory effect was proportional to the concentration of 1-MCP.The above results indicated that the treatments with different concentrations of 1-MCP all inhibited the process of wax change of fragrant pear during cold storage.(4)Changes in storage quality and physiological indicator of fragrant pear treated with 1-MCP and their correlation with changes in wax quality.1-MCP treatment had good fresh-keeping effect on fragrant pear.Inhibited respiratory rate and ethylene release rate,postponed the peaks of both.Delayed the rise of WSP content,PG activity,CX activity and weight loss rate.Inhibited the decrease of cellulose content,firmness and total phenol content during storage for 40~100 d,1.2 ?L/L 1-MCP was outstanding.According to the correlation analysis,1.2 ?L/L 1-MCP may inhibit the decline of cellulose content by delaying the decrease of the relative content of enoic acid and aldehydes;it is possible to suppress the upward trend of weightlessness rate by delaying the increase of wax extraction content.1-MCP may also suppress the rising trend of WSP content,PG activity,and CX activity by delaying the increase of the relative content of alcohols and the decrease of the relative content of enoic acids and aldehydes;it is possible to suppress the upward trend of ethylene release rate by delaying the decrease of the relative content of enoic acid;it is possible to suppress the upward trend of weight loss rate and the downward trend of hardness by delaying the decrease of the relative content of enoic acid and aldehydes;it is possible to suppress the decreasing trend of cellulose content by delaying the decrease of the relative content of esters.Noted 1-MCP slowed down the changes of epidermal wax extract content,relative content of components and ultrastructure during the ripening and senescence of fragrant pear.