Study On The Postharvest Loss Reducing Technology Of Rapeseed

This paper mainly studies the postharvest loss reducing technology of rapeseed.The mainly results as follow:(1) The rapeseed was treated with six kinds of emergency treatment methods (UV,ozone, sodium chloride, metabisulfite, propionic acid and hypoxia sealed), and storedat25℃. Results showed that:Compared with the control (untreated rapeseed), growth of mold were inhibitedunder all6kinds of emergency treatment methods. Generally speaking, all qualityindexs determined in rapeseed treated with UV were better than those in the control.UV treatment is the optimum emergency treatment method for rapeseed.(2) Under different temperature (40℃,50℃,60℃) and air volume(20m3/h,25m3/h,30m3/h), we attained the drying curve and drying rate curve of rapeseed, andanalyzed the influences of different temperature and air volume on rapeseed quality.The results of hot-air drying showed that:Drying time is shortened with the increase of temperature under the same airvolume; At the same drying temperature, the larger air volume, the shorter dryingtime；With the rise of drying temperature and air volume increases, the drying rateincreases.The quality indexs has the smallest differences between rapeseed drying under40℃and original sample. At40℃,30m3/h air volume has the shortest dring timeand the fastest drying rate, so40℃,30m3/h is the optimum combination of hot-airdrying condition for rapeseed.(3) The rapeseed was stored under the treatment combination of three levels oftemperature (15℃,25℃,35℃) and five levels of oxygen volume fraction (2%,5%,10%,15%,21%), in order to study the effect of controlled atmosphere storage withN2on the storage quality of rapeseed. The changes in quality of rapeseed wereinvestigated per20days during syorage, and the results showed that:Germination rate and oil content of rapeseed was slowly descend with thestorage time prolonging. They were extremely significantly positive correlated (r=0.536). At the same oxygen volume fraction, the higher the storage temperature was,the more rapidly the reducing of germination rate and oil content. The effect ofdifferent oxygen volume fraction on rapeseed’s germination rate were significant (0.01＜P＜0.05), on oil content were not significant (P＞0.05).The acid value and peroxide value of rapeseed was rised gradually in the storagetime. They were extremely significantly positive correlated (r=0.941). At the samestorage temperature, the lower the oxygen volume fraction was, the increasing of acidvalue and peroxide value was slower; at the same oxygen volume fraction, the higherthe storage temperature was, the more rapidly the increasing of acid value andperoxide value. Storage time, oxygen volume fraction, temperature as well as theinteraction between them showed extremely significant effects on moisture content,acid value and peroxide value of rapeseed (P＜0.01).The correlation between germination rate and acid value, germination rate andperoxide value, oil content and acid value, oil content and peroxide value were allextremely significantly negative correlated. The Correlation coefficient were-0.865,-0.784,-0.720and0.752respectively.