1-MCP处理对几种脆肉梨果实贮藏品质及采后生理的影响

Effects of 1-methylcyclopropene(1-MCP) on quality and physical characteristics of crispy pears during storage

【目的】研究1-甲基环丙烯(1-MCP)处理对‘酥梨’‘红香酥’和‘玉露香’果实贮藏品质和采后生理的影响,为梨果实贮藏保鲜技术提供理论支持。【方法】采后果实经1.0μL·L-11-MCP处理12 h后,常温(20±1)℃贮藏30 d,每隔4 d测定各项品质和生理指标。【结果】与对照果实相比,1-MCP处理有效延缓几种脆肉梨果实硬度、可溶性固形物含量、可滴定酸含量和维生素C含量的下降,抑制乙醇、丙二醛(MDA)含量的升高,降低超氧阴离子(O2-)产生速率和H2O2含量的积累,贮藏后期(15~30 d)经1-MCP处理后的果实仍维持了较高的超氧化物岐化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、抗坏血酸过氧化物酶(APX)活性。【结论】1-MCP通过维持抗氧化酶活性而达到延缓梨果实品质下降和衰老,延长贮藏保鲜时间,1-MCP处理后货架期30 d内食用梨果实品质保持良好,货架期延长10 d以上。

【Objective】In this paper,‘Suli’‘Yuluxiang’and‘Hongxiangsu’pears were used to study the effects of l-MCP on the storage quality and some postharvest physiologies.【Methods】‘Suli’‘Yuluxiang’and‘Hongxiangsu’pears are abundant in Shanxi Province.All those pears are less fiber,crisp,juicy,sweet,tasty and fragrant.They were immediately transported to Institute of Pomology of Chinese Academy of Agricultural Sciences(Xingcheng)by car the day after picking.After two days of transport pears were immediately stored in refrigerated provision store.This three pears were selected the size uniform,free of visible injuries and defects,then were immediately treated with 1-MCP(1.0μL·L-1)for 12 h in the sealed polyvinyl chloride(PVC)plastic bags of 0.1 mm thick,following stored at room temperature(20±1)℃within 30 days.The quality and physiological indicators were assayed every 4 days.The quality indicators included firmness,soluble solid content(SSC),titratable acid(TA)content,vitamin C content.The physiological indicators included ethanol content,malonaldehyde(MDA)content,superoxide anion(O2-)production rate and H2O2 content,SOD,POD,CAT and APX acitivity.【Results】Compared with the control fruits,the treatment of 1-MCP could delay the decline of firmness and soluble solid,TA and vitamin C content,inhibit the increase of ethanol and MDA content and reduce the O2-production rate and H2O2 content.After storage 30 d,the average firmness of 1-MCP treatment decreased by 4%-11%and the averagefirmness of control decreased by 15%-16%.At the same time,the SSC of‘Suli’could reach above 12%,the SSC of 1-MCP treatment of‘hongxiangsu’was more than 4 percent higher than the control samples and the SSC of 1-MCP treatment of‘Yuluxiang’could maintain above 11%than the control.TA content was the fastest decline indicator in quality indicators.In general,the fruits have a good flavor that have high content of sugar and moderate content of acid.When store up to 30 d,the TA content of 1-MCP treatment of‘Suli’decreased by 36%,however,the control decreased by 52%.The TA content of the control of‘Hongxiangsu’was 1.11 times of 1-MCP treatment and‘Yuluxiang’control sample was three times less than that of 1-MCP treatment;the treatment of 1-MCP could maintain SOD,POD,CAT and APX acitivity at later stage of storage(15-30 d).But there was a big difference among different varieties.When store up to 25 d,O2-production rate of‘Suli’were increasing in control and 1-MCP treatments,at the same time the activity of SOD reached the second peak,the pears enter into the aging process.POD and CAT had a certain effect to remove the H2O2.The activity of POD associated with H2O2 content.While the CAT and APX might participate in the other reactive oxygen species metabolism.1-MCP treatment effectively delayed the peak of SOD in‘Hongxiangsu’.O2-production rate was rising when 0-10 d of storage.At the same time,the activity of SOD was slowly rising;Store up to 15 d,the contents of H2O2 of the control and 1-MCP treatments were slight decreasing,then(20 d)rising.The activity of POD and CAT(the control and 1-MCP treatments)respectively reached the peak at 15 d and 20 d.The activity of APX reached the peak when store up to 15 d(only 1-MCP treatment).The treatment of 1-MCP kept the high activity of SOD in‘Yuluxiang’,maintained low O2-production rate;Store up to 15 d,the contents of H2O2 of control and 1-MCP treatments reached the peak,and the content of H2O2 of control was higher than 1-MCP.At the same time,the activity of POD also reached the peak,but the activity of CAT was slowly decreasing,the activity of APX was rising.Through the above analysis,SOD,POD,CAT and APX interacted with each other.We could obtain that 1-MCP treatment could maintain higher enzyme activity(15 30 d)of this three pears【.Conclusion】1-MCP treatment could slow down the decline of pears’quality and senescence by maintaining antioxidant enzyme activity,extended the the shelf life.Integrated with above comparative analysis,different cultivars of pears were not the same in regulatory mechanisms.Three pears were treated by 1-MCP after 30 d shelf life at room temperature(20±1)℃still taste crispy,sweet and juicy,still maintain good quality without other off-flavor.But for‘Yuluxiang’which has thin skin and high sugar should try to short the shelf life to prevent the phenomenon of return-sugar.In this study,the pear of‘Yuluxiang’after treated by 1-MCP could be delayed about 15 d,did not show that the phenomenon of return-sugar.So the treatment of 1-MCP at(20±1)℃within 30 d could maintain good quality for this three crispy pears,and extend the shelf-life of more than 10 d.