Application Of 1-methylcyclopropene Treatment Technology In Grape Preservation

The grape is a kind of berry fruit which is rich with nutrition.The skin of grape is thin and juicy,which is easy to damage and thresh and the inherent physiological characteristics of grape is not conducive to its storage.In China,the annual post-harvest grape loss rate is as high as 20%.What's more,the excessive use of fertilizers and pesticide residues is serious,and the demand for green fruits is increasing day by day.In this paper,Summer Black,Hue Honey and Sunshine Rose were used as test materials.Organic cultivation and common cultivation were adopted.The effects of different cultivation modes,different concentrations of1-methylcyclopropene(1-MCP)preharvest treatment and 1-MCP post-harvest treatment on grape quality were investigated to explore the best preservation method and concentration.Effects of different cultivation modes on grape quality showed that organic cultivation could significantly improve post-harvest storage and shelf quality of grape(p<0.05).Compared with ordinary cultivation,organic cultivation significantly reduced the browning rate,rot rate and water lost rate of grape stalks(p<0.05),what's more,organic cultivation could maintain higher content of titratable acid and Vc,inhibit fruit ripening,delay the yellowing of ripe skins,and promote the volatilization of characteristic volatile substances.Effects of 1-MCP post-harvest treatment(1,3,5 ?L/L)on grape quality showed that 3/5 ?L/L 1-MCP treatment significantly inhibited the browning rate,rot rate,drop rate,weight loss rate(p<0.05)and delayed the softening progress of grape flesh.1 ?L/L 1-MCP treatment significantly inhibited the respiratory intensity and ethylene generation rate(p<0.05),delayed the change of skin color.However,post-harvest1-MCP treatment inhibited the volatilization of key volatile substances,especially 1.0?L/L group,while 3 ?L/L had more typical grape aroma.Via comprehensive comparison,the optimal post-harvest treatment concentrations were 3 ?L/L in Summer Black,3 ?L/L in Hue Honey and 5 ?L/L in Sunshine Rose.Effects of 1-MCP preharvest treatment(0.5,1.0,1.5 ?L/L)on storage and shelfquality showed that 1-MCP preharvest treatment could significantly inhibit the browning rate,rot rate and drop rate(p<0.05).The 1-MCP treatment before harvest inhibited the volatilization of key volatile substances,0.5 ?L/L group had the strongest inhibition,while 1.0 ?L/L had the best retention effect.According to the comprehensive comparison,the most suitable 1-MCP preharvest concentrations are 1?L/L in Summer Black,1 ?L/L in Hue Honey and 1 ?L/L in Sunshine Rose.According to the comprehensive analysis of principal component analysis and least partial square regression method,the comparison with the effects of 1-MCP preharvest and post-harvest treatment on grape quality were investigated.The optimal treatment conditions were as follows,3 ?L/L 1-MCP post-harvest treatment in Summer Black and Hue Honey,5 ?L/L 1-MCP post-harvest treatment in Sunshine Rose.Compared with the preharvest treatment,the 1-MCP post-harvest treatment could better maintain the firmness of flesh,inhibit the respiratory intensity and the ethylene production of fruit stalk.Meanwhile,the 1-MCP post-harvest treatment of the grapes maintained high sugar content,low acidity and better taste.In this paper,the optimum 1-MCP treatment method and concentration of different grape varieties were studied.It has wide application value.