Study On Quality Change Of Rice During Aging Under Three Drying Conditions

Rice is the main ration in China,and the newly harvested rice needs to be dried to improve its aging storage performance and processing suitability.On the basis of the previous research in our laboratory,this project takes aolong Silk seedling and Shengtaiyou 018 as the research object,and adopts three drying methods of continuous drying,isothermal slow-suiting drying and low-temperature dry-high temperature slow-suiting drying to dry rice.After analysis of different drying technology on dry contest in the aging process of milled rice,the physical and chemical index,antioxidant activity,microstructure,texture and the change of volatile component,the effects of different drying methods on the exploring rice storage mechanism,the effect of aging process how best to dry the screening of rice,this study to improve the quality of rice storage in China have certain research significance.The main research contents and results are as follows:The effects of three drying methods on water content,water molecular distribution,broken rice rate,fatty acid value,mitochondrial membrane fluidity and membrane permeability of seed embryo during rice aging were studied.The results showed that during the aging process,the water content of two varieties of rice decreased after three kinds of drying,but after low temperature drying and high temperature slow sueing drying,the water content of rice decreased the least,aolong Silk seedling and Shengtaiyou 018 decreased by 2.96%and 2.59%,respectively.The distribution of water molecules in rice under the three drying methods shifted to the left with the extension of aging time,but the amplitude of T2 shift to the left was the lowest after low temperature drying and high temperature slow-supping-drying,indicating that the rice was subjected to the least stress.Among the three drying methods,the two kinds of rice treated by low temperature drying and high temperature slow suwing had the lowest broken rice rates before and after aging,among which the broken rice rates of Aolong Silk seedling and Shengtaiyou 018 were 6.12%and 10.51%respectively,while the broken rice rates of rice treated by continuous drying were the highest.The rate of broken rice of Aolong Silk seedling and Shengtaiyou 018 was 8.52%and 12.86%,respectively.After three kinds of drying,the fatty acid value of the two varieties showed an increasing trend in the aging process,but the fatty acid value of the two varieties showed the lowest increasing rate after low temperature drying and high temperature slow soiling drying.After three kinds of drying,two varieties of rice in the aging process,the kind of embryo mitochondrial membrane fluidity and permeability are affected by a certain degree,but the low temperature drying-high temperature tempering drying after the two varieties of rice,the aging process,the embryo mitochondrial membrane fluidity and permeability affected by minimum,after continuous dry rice in the aging process,The fluidity and permeability of the mitochondrial membrane of the embryo are most affected.The experimental results showed that low temperature drying-high temperature slow-supping drying rice had the best storage quality in the aging process,followed by isothermal slow-supping drying,and the worst was continuous drying.DPPH radical scavenging capacity,total reducing power,SOD value,GR value,malondialdehyde(MDA)content and other antioxidant indexes of two varieties of rice treated by three kinds of drying were studied during aging.The results showed that the DPPH radical scavenging ability and total reducing power of the two varieties of rice treated by three drying methods were the strongest in the aging process,followed by isothermal slow supping drying,and the worst was continuous drying.The SOD value of rice under different drying conditions showed a downward trend in the aging process.The SOD value of Shengtaiyou 018 decreased 34.81unit,37.48 unit and 39.93 unit respectively after aging under low temperature drying,high temperature slow suwing drying,isothermal slow suwing drying and continuous drying.SOD value of Aolong seedling rice showed the same trend.During the aging process,the GR value of rice treated by the three drying methods increased first and then decreased,and reached the maximum value at 20 days.The two varieties of rice treated by low temperature drying and high temperature slow su drying all had the maximum GR value,and the maximum GR value of Shengtaiyou 018 and Aolong seedling was 2.32 mU/mL and 3.73 mU/mL,respectively.The MDA content of the two varieties of rice treated by three drying methods showed an increasing trend in the aging process,but the increasing rate of MDA content was the lowest after low temperature drying and high temperature slow souping drying,and the increasing rate of MDA content was the highest in the continuous drying process.The results showed that low temperature drying and high temperature slow suiting drying rice showed the best antioxidant activity in the aging process,indicating better storage quality.The changes of microstructure,texture,taste and volatile matter of two varieties of rice treated by three kinds of drying during aging were studied.The results showed that two varieties of rice after three kinds of drying,the aging process,rice and its kind of embryo microstructure were different degree changes in mitochondria,show the mitochondrial outer membrane gradually disintegrated,lining,lining and ridge completely disappeared,but the low temperature drying-high temperature tempering after drying the two varieties of rice and its kind of embryo mitochondria microstructure changes is minimal.The hardness and elasticity of rice treated by the three drying methods increased and decreased during the aging process,and the texture and taste quality of rice became worse.However,the hardness increase and elasticity decrease of the two varieties of rice treated by low temperature drying and high temperature slow su drying were the smallest,and the hardness increase of Aolong Silk seedling and Shengtaiyou 018 were 574.1 and 756.1 respectively.The elastic reduction ranges of the two varieties were 1.86 and 11.5,respectively.The comprehensive score of food quality of the two varieties was the highest after low temperature drying and high temperature slow soil-drying.Three kinds of drying process of rice,the main alcohol volatile components were aging process along with the aging time and declining,with no fresh esters substance and aldehyde rise,including low temperature drying-high temperature tempering drying after the two varieties of rice,the volatile substances in the aging process of change is minimized.The experimental results showed that the changes of microstructure,texture,taste and volatile substances in the aging process of low temperature drying and high temperature slow suiting drying rice were the least,and the storage quality was better.