Study On Storage Stability Of Green Wheat Kernel

Green wheat kernel was harvested from immature wheat,peeled and quick-frozen,which rich in protein,dietary fiber,polyphenols antioxidants.Green wheat kernel,when harvested,would carry a large number of microorganisms.After harvested,the activities of polyphenol oxidase,peroxidase and lipase were very strong.In addition,green wheat kernel was a complete plant body,and its own respiration would also consume its own nutrients,resulting in the quality of green wheat kernel in the storage process.In this study,the changes of physical and chemical properties and storage properties of green wheat kernel without stabilization treatment at room temperature,4℃ and-20℃ were firstly studied,and then the quality of green wheat kernel with stabilization technology was explored,and the changes of green wheat kernel after stabilization treatment at the same temperature were extended.(1)The unstable green wheat kernels had the fastest water loss rate at room temperature storage,and the water content of 4°C and-20°C storage fluctuated from 53.2% to 55.6%,and the water changes led to the decrease of the 1,000 grain weight of green wheat kernels in normal temperature storage and remained stable in 4°C and-20°C storage.The temperature difference led to different changes in the L*,a*,and b* values of green wheat kernels,which caused browning of green wheat kernels during storage.The content of phenolic acids and flavonoids was gradually reduced at room temperature and-20°C.The degradation rate of phenolic substances was > 4°C storage at room temperature >-20°C storage,indicated that low temperature storage can effectively inhibit the degradation of phenols in green wheat kernels.The activities of polyphenol oxidase,peroxidase and lipase in the storage at room temperature and 4°C in the storage of unstable green wheat kernels were increased first and then decreased,while the fatty acid value continued to increase.There were no significant changes in the activity and fatty acid values of these three enzymes in the-20°C storage.Untreated green wheat kernels were stored at room temperature for up to 2 days and stored at4°C for up to9 days.(2)The three stabilization treatment technologies of superheated steam,microwave and hot water bleaching can reduce the activity of polyphenol oxidase,peroxidase and lipase of green wheat kernels,and at the same time have a significant inhibitory growth effect on microorganisms.Under the condition of 1 min treatment at 160°C,the activities of polyphenol oxidase,peroxidase and lipase in green wheat kernels decreased by 51.8%,44.9% and 47.1%,fatty acid values decreased by 57.1%,the total inactivation rate of colonies was more than44.57%,and the inactivation rate of mold was more than 34.9%.(3)After the stabilization treatment of green wheat kernels,the moisture content and1000 grain weight were slowly reduced with the extension of storage time,and the browning rate of green wheat kernels slowed down during storage.The phenol content in green wheat kernels fluctuated during storage,and the previous treatment increased the initial phenol content of green wheat kernels.After stabilization,green wheat kernels can inhibit the increase in the activities of polyphenol oxidase,peroxidase and lipase in green wheat kernels,and delayed the growth rate of fatty acid values during storage time.After the stabilization treatment of green wheat kernels,it can be effectively extended by 1 day in room temperature storage,and it could be stored at 4°C for 15 days.It was explained that the superheated steam stabilization treatment can effectively extend the storage period of green wheat kernels.