Change Of Quality During Storage And The Effect Of Phosphate Fertilizer On Rice Storage

Rice is one of the most important crops in agriculture in northern China.It is characterized by maturity once a year.There is a storage period of nearly 10 months before processing,and with storage,the quality of rice will deteriorate.Pan Jing is an area rich in high-quality rice.It is well-known in the country for its rice and crab breeding model.The quality of rice is the key to its value..In addition,many studies have been published on fertilization methods,While increasing yields by fertilization,the also need to pay close on quality.The changes of rice quality during the whole storage period were studied in this article,the effect of nitrogen fertilizer on rice quality was evaluated,and the possibility of fertilization affecting rice storage tolerance was analyzed.The changes of rice nutritional quality were reflected by measuring the nutrition-related indexes of rice,such as protein,amylose and fat content,and the change trend of milling quality was characterized by measuring brown rice rate,milled rice rate and head rice rate.The sulfhydryl content in rice,water absorption and swelling of milled rice were measured to explore the changes of cooking quality.The study shows that:1.During storage,starch content decreased by about 5% after 3 month;The proportion of protein has increased,from 5.27% to 6.39%;There was no significant change in fat content and almost no difference in brown rice rate,and the polished rice rate has continued to decrease since March.The integrity of polished rice increases and then decreases with time,which may be related to moisture.2.The results by viscosity characteristics show,application of phosphate fertilizer will increase the viscosity,maximum viscosity and final viscosity of rice flour.The effect of increasing storage time is more significant than phosphate treatment.During storage,the hardness of rice increased by nearly 50%,and its viscosity and elasticity were opposite to hardness.The water absorption and swelling of polished rice are significantly reduced,The changes in starch internal structure and thiol content,Changes in starch internal structure and thiol content may be the main influencing factors.Correlation between thiol content and hardness is as high as 0.886 3.The study found that both the peroxide value and the content of MDA,which reflect the degree of lipid oxidation,increased during the storage period,and increased with the increase of nitrogen fertilizer application.The contents of polyphenols and flavonoids were positively correlated with the amount of nitrogen fertilizer application,and there were significant differences in the ability of scavenging free radicals and peroxidized free radicals in rice with different nitrogen fertilizer treatments.Nitrogen fertilizer treatment significantly increased the activity of phenylalanine ammonia lyase,but inhibited the activity of catalase and peroxidase.The causes of lipid deterioration need to be further studied.