Study On Postharvest Physiology Structure Change And Related Enzyme Metabolism Of Fresh-eating Waxy Corn

Fresh waxy corn shows high starch content and low water content. Thus, the physiological basis for changes in eating quality may differ between fresh waxy corn and other fruits and vegetables. It means that the postharvest changes in carbohydrate of common fruits and vegetables were not applicable to instruct the storage and retail of fresh waxy corn. In this study, we report the changes of related carbohydrate and associated enzyme activities and the correlations between them. The research realizes the reason of eating quality changing and controlling factors. These results can promote the quality of fresh waxy corn in the processing, storage and retail.The content of sucrose, reducing sugar continued to decline. The content of toatal starch, amylose and amylopectin all reached the peak value at1st day, followed by little change in amylose, amylopectin content decreased slightly, with toatal starch showed an increase trend. Compared with20℃storage temperature,the content of sucrose, reducing sugar and amylopectin was high,while the content of amylopectin and toatal starch was low when stored at0℃storage temperature. The anabolism about inverting of soluble sugar to starch occupied the dominant position for postharvest fresh waxy corn. The inverting of soluble sugar to starch and amylose to amylopectin can be reduced when stored at0℃.Compared with20℃storage temperature, the low temperature improved the activities of UDPGPPase to promote the sucrose degradation and reduced the activities of SSS and GBSS to slow down the process of starch synthesis. The activities of SBE would be restrained and DBE be strengthend to promote the amylose synthesis when stored at0℃The activities of PAL and C4H was promoting by the low temperature. And while the activities of4CL appeared in an inhibition, the activities of4CL coenzymes A ester synthesis, also indirectly determine the synthesis of lignin.So, low temperature storage at least to slow the speed of lignification;This study on the activities of CAD and DFR under low temperature conditions showed a curve with ups and downs, while at room temperature them steadily falled.It suggesting that postharvest temperature or take proper preheat fresh-eating waxy corn processing can control the activities of CAD and DFR, and thus control the formation of lignin;This research shows that The activities of PPO less affected by temperature, and greatly influenced by the storage time, the Browning occurred in middle and later periods of the storage of fresh-eating waxy corn, so save time or try to stop the processing timely will protect the fresh color and tasty quality.