Effect Of Controlled Atmosphere With N₂on Storage Stability Of Sorghum

Sorghum is used widely throughout the world as grain and forage crop, and currentlytraditional storage methods can’t meet the social demand for green food raw materials. Thisstudy takes three methods of conventional storage,90%N2and98%N2controlled atmosphereat different temperatures on sorghum storage for180days, and make a inspection every45days on sorghum quality. The results show that:90%N2controlled atmosphere storage can guard against insects well. During storage,germination rate were gradually decreased, and relatively more slowly at low temperature orin N2controlled atmosphere storage. Viability was consistent with germination rate, after180days storage at20℃, conventional and98%N2storage were decreased by19%and10%respectively, while at25℃22%and15%respectively, and at35℃storage after90daysviability of three methods were decreased dramatically by64%,56%,39%respectively to180days. CAT activity decreased gradually, and N2controlled atmosphere storage had significantremission of enzyme activity decrease. Conductivity gradually increased, and especially athigher temperature, in N2controlled atmosphere storage conductivity increased relativelyslowly.Starch content decreased along with storage time extension, and more slowly in N2controlled atmosphere storage, after180days the content decreased by3-4%. As insectsroutined at25℃and30℃, the starch content decreased by10.3%and11.9%respectively.Crude protein and fat content were decreased slowly with a narrow range, and in N2controlled atmosphere storage both were more stable. The content of reducing sugar began todecline at35℃in conventional storage after45days, and at the other temperatures in0-90days reducing sugar content increased gradually, at20℃after135days the content decreasebegan, at25℃and30℃began after90days. In N2controlled atmosphere storage reducingsugar content increased in90days storage, after90days that began to decline but relativestability. Under high temperature, the content of reducing sugar changed with relatively widerrange with storage time extension.In conventional storage at20℃alpha amylase activity increased gradually in135days, after135days that decreased gradually, at the other temperatures all increased in90days, decreased after90days. In N2controlled atmosphere storage, alpha amylase activitywas stable comparatively, and it’s more stable in the higher concentration of N2. In conventional storage the characteristic values of the starch RVA-curve decreased with thestorage time extension gradually, that showed that the water absorptivity of starch granulesdecreased, thermal paste stability and cold paste stability enhanced, starch paste hardness atroom temperature reduced. In N2controlled atmosphere storage all characteristic valuesincreased in90days, deceased after90days gradually. This showed that the waterabsorptivity of starch granules increased gradually in90days storage, thermal paste stabilityand cold paste stability reduced, starch paste hardness at room temperature decreasedgradually, after90days the water absorptivity decreased gradually, thermal paste stabilityand cold paste stability enhanced, starch paste hardness at room temperature reduced. Thestorage effect in N2controlled atmosphere storage at higher temperature was alike withconventional storage at lower temperature, that showed that it can alleviate the effect of hightemperature on sorghum processing quality in N2controlled atmosphere storage.