Effect Of Different Storage Conditions On The Stability Of Red Bean

The material of this paper is red bean planted in Heilongjiang province,in the storage period of 180 days,we set three moisture content(11.1%,12.8%,14.9%),three temperature(15 ?,22 ?,30 ?)and three storage methods(conventional airtight,nitrogen inflator,vacuum).In this process,we studied the quality of red bean(storage quality and nutritional quality),the change of gelatinization properties,the microstructure and the content change of volatile gas were measured by usingscanning electron microscope and Fourier transform infraredspectroscopy and GC-MS.The results are as follows:In the course of the experiment,the germination rate of red beans showed a decreasing trend,the value of conductivity,fatty acid,malondialdehyde,drop showed an upward trend.The five indexes are affected by water content,storage time and storage temperature.The higher water content,the higher temperature,the longer time,the more obvious the change.The germination rate of red beans was not significantly affected by the storage method,the remaining indexes were significantly affected by storage conditions.During the whole storage period,the total starch content of red beans decreased,the content of reducing sugar increased first and then decreased,the proportion of amylose increased slightly,the proportion of amylopectin decreased gradually.The effect of storage on the total starch and amylopectin content of red bean was not significant,and the water content,storage temperature and storage time had significant effect on total starch content and amylopectin content.The storage time had a significant effect on the reducing sugar content of red beans,the water content,storage temperature and storage method had significant influence on the content of reducing sugar.The content of water had no significant effect on the amylose content of red bean,and the storage temperature,storage method and storage time had significant influence on amylose content.During the whole storage period,the final viscosity value,peak viscosity value and setback of red bean showed a gradual increase with time.The water content,storage temperature and storage time had significant effect on the final viscosity value,peak viscosity value and setback,while the storage method had no significant effect on the three indexes.At the beginning of storage,the protein matrix and starch granules were tightly packed,as the storage time is prolonged,the nutrients are gradually consumed,the protein matrix is degraded,the binding of the starch granules to the protein matrix becomes weaker,and even falls off the matrix.As the storage temperature increases,the combination of starch and protein becomes loose.With the extension of storage time,the ?-helix in the secondary structure of protein gradually becomes ?-turn structure and ?-sheet structure,which leads to the tendency of ?-helix structure gradually decrease,while the?-turn structure and?-sheet structure showed a gradual increasing trend.The irregular curl structure will be transformed into ordered structure in a specific environment,so the irregular curl structure tends to decrease with the prolonging storage time.There was a significant positive correlation between the water content of red beans and the content of?-sheet structures,and there was a significant correlation between storage time and four secondary structure contents.At the beginning of storage,there were 17 and 18 kinds of volatile substances in red beans with water content of 11.1% and 14.9% respectively.After 180 days of conventional storage,the volatile substances in the red bean samples with water content of 11.1% and 14.9% were 31 species and 35 species respectively.After 180 days of vacuum storage,the volatile substances in the red beans samples with water content of 11.1% and 14.9% were 27 species and 30 species,which shows that compared to conventional storage,vacuum storage has less volatile substances.Compared with conventional storage,the amount of alcohol in the sample was reduced by 1 in the vacuum storage,the number of alkanes decreased by 2,the amount of olefins decreased by 4 species,but the amount of ester was increased by 3.Higher levels of aldehydes are responsible for the spicy flavor of food.The aldehydes were not detected in the initial samples.After 180 days of vacuum storage,trans-2-nonenal and dodecaldehyde were detected,and the content of dodecaldehyde was 3.57%.Increased ester content means that the oxidative decomposition of fatty acids is accelerated.In the whole storage process,(1-hydroxy-2,4,4-trimethylpentan-3-yl)2-methylpropionate,2,2,4-trimethyl-1,3-pentanediol diisobutyrate and dibutyl phthalate have been present,and the content fluctuation is not regular.After 180 days of storage,emerging esters are: ethylene glycol butyl ether acetate,?-amyl-?-butyrolactone,hexyl cyclohexyl carboxylate,isooctyl octanoate and monoethyl phthalate.