Study Of1-MCP+ClO₂on Controlled Freezing-point Storage Preservation Technology And Aging Regulatory Mechanism Of The Table Grape

1-MCP is a new type of ethylene receptor inhibitor found in recent years, which can irreversibly effect on ethylene receptor, thereby blocking the normal combination of receptor and ethylene, thus inhibits the induction and fruit ripening related a series of physiological and biochemical reactions. Chlorine dioxide （ClO2） is a strong oxidant, and is internationally recognized as the excellent performance, the best food preservative and bactericide, as it does not affect the flavor and appearance quality of food, and can effectively reduce foodborne disease.1-MCP is recoganized as a disinfectant of A1-level security by World Health Organization （WHO）. SO2is the most commonly used preservative in grape storage, play an important role in the storage and preservation of the grape. However, residual problem and harms to human body and environment of SO2has attracted more and more attention.This experiment investigated storage quality of grapes during controlled freezing-point storage, with1-MCP and ClO2as grape preservatives, so as to select a new grape preservative as an alternative to SO2. With Muscat and red global grape as objects, this article study the following three aspects:（1） The preservation effect and response mechanisms of grapes during controlled freezing-point storage （-0.3℃±0.3℃）;（2） The effect difference between ClO2and CT-2during controlled freezing-point storage, and the synergistic effect of ClO2+CT-2treatment;（3） Grape preservation effect and its function mechanisms of1-MCP+CIO2treatment during controlled freezing-point storageThe conclusions are as follows:1、Ordinary cold storage vs controlled freezing-point storage of grape. The results show that at the end of controlled freezing-point storage, weight loss and berry drop rates of Muscat grape were12.34%and10.80%respectively, lower than that of ordinary cold storage; and flesh firmness and Vc content were1.14kg/cm2and2.17mg/100g respectively, higher than that of ordinary cold storage. The total soluble solids and Vc content of red global grape during controlled freezing-point storage were1.42%,3.27mg/100g respectively, higher than that of ordinary cold storage. Controlled freezing-point storage effectively inhibited the reduction of grape nutritional quality, MDA content of this two grapes are7.17and2.13μmol·g-1lower at the end of the storage, POD and SOD activity had also been improved, so controlled freezing-point storage was better to delay fruit aging.2、Effect of ClO2and CT-2as preservatives on storage quality of grape during controlled freezing-point storage. The results showed that comparing to ClO2treatment, CT-2improved grapes quality, and delay fruit aging during storage; CT-2treatment extended storage life of Muscat grape from45d to90d. Berry drop and decay rates were3.13%and8.91%lower thanthat treated with ClO₂at45d. Decay rates and stems browning index were21.63%and37.50%at90d, while the control and CIO： treatment almost completely decomposed withrotten stems and severe browning. Flesh ifrmness and Vc contcnt of CT-2+ClO₂were0.61kg/cm2and0.78mg/100g lower，MDA contcnt2.72j.i’mol#"g higher than those just treatedwith CT-2at90d. CT-2+ClO₂was not as good as just treatment with CT-2, therefore, nosynergistic role exetred with CIO： and CT-2.3、Effectof treatments with1-MCP or ClO₂on grape storage quality during controlledfreezing-point storage. At45d, berry drop rate of Muscat grape under1-MCP+ClO₂treatmentwere4.12%and3,67%respectively, lower than that of treatments with just1-MCP or CIO：.Treatment with I-MCP+ClO₂effectively inhibited ethylene production and MDA of Muscatgrape. At the storage end of red global grape，decay rate of berries treated with l-MCP+CIO:were12.28%and3.49%higher than that of fruits treated with just1-MCP or CIO: Totalsoluble solids and Vc content of berries treated with I-MCP+ClO₂reduced slowliest, PODand SOD activity were higer than that of berries treated with just one chemical Therefore,treatment with I-MCP+ClO₂combined the advantages of tratmcnt with just I-MCP or ClO₂.4、Duringcontrolled freezing-point storage,1-MCP+C102failed to extend the storagelife of Muscat grape （45d），while treatment with CT-2extended the storage life to90d.Therefore I-MCP+ClO₂can not replace CT-2as a preservative of Muscat grape. However,SO2injury of Red Global Grape treated with卜MCP+ClC^did not appear during storage,increase of MDA contcnt in the berries was also inhibited, thus I-MCP+ClO₂can rcplaceCT-2as an preservative of Red Global Grape.