Effects Of Different Storage Temperature And Humidity On Quality Characteristics Of Maize

China has a large quantity of annual production and consumption of corn,a large number of corn needs to be stored,among which improper storage leads to the deterioration of the quality of corn that resulting in a staggering amount of loss.The storage environment is very important for the reasonable preservation and subsequent production and processing of corn.Explore the physiological and biochemical properties of corn in different storage environments,as well as changes in key nutrients and storage(A group: 15?,50%RH;B group: 20?,65%RH;C group: 28?,75%RH;D group: 35?,85%RH)by using Zheng Dan958,Wei Ke 702 and Xun Dan 29 as materials,the results showed that:(1)With the extension of storage time,three kinds of selected strains of maize germination potential,germination rate,germination index and vigor index change are reduced(p<0.05),and the higher the storage temperature and humidity environment,the greater the change.Zheng Dan 958,Wei Ke 702 and Xun Dan 29 at group A to 240 d of storage,three kinds of maize germination rate unchanged,storage to 240 d at group D,three kinds of maize germination indexes fell to 0.Three corn peroxidase activity and the activity of catalase,superoxide dismutase,dehydrogenase activity of the extension of storage time showed a trend of decrease(p<0.05),and the change amplitude increases with the increase of environmental temperature and humidity storage,such as: When Zheng Dan 958,Wei Ke702 and Xun Dan 29 were stored for 480 days,the reduction of SOD activity in group D was2.04,1.88 and 1.90 times of that in group A,respectively.The soluble sugar content of maize was reduced as storage time increased,malonedialdehyde content increased(p<0.05).The higher the temperature and humidity of the storage environment,the greater the variation range was.(2)Of the total protein content in corn with the extension of storage time is significantly reduced(p<0.05),a protein component changes,including albumin,globulin,gliadin content decreases,glutelin content showed a trend of increase,the higher the storage temperature and humidity,the more visible changes of protein components(When stored for480 days at group D,medium and small molecular weight protein hydrolysis,albumin 20 k Da?22 k Da protein subunits basic disappearance,globulin 40 k Da?45 k Da protein subunits basic disappear,while the remaining three storage environment no protein subunits disappear).Similar to corn crude protein,the content of total starch decreased with the prolonging of storage time(p<0.05),the decrease rate of total starch content in high temperature and high humidity environment was significantly higher than that in low temperature and low humidity storage environment(The decrease rate of total starch content in Wei Ke 702 stored at group D to 480 d was 1.44 times of that at group A).With the prolongation of storage time,the content of amylose increased(p<0.05),with the decrease of starch gelatinization viscosity and the increase of gelatinization temperature.(3)As for the storage quality of corn,the bulk density decreased with the prolonging of storage time;Fatty acid value and total number of mold colonies showed an increasing trend(p<0.05).When stored for 480 days at group D the loss rates of Zheng Dan 958,Wei Ke 702 and Xun Dan 29 were 1.91,2.40 and 1.82 times of those at group A,respectively.Fusarium moniliforme,Aspergillus glaucus,Penicillium is the dominant molds on the surface of maize.