Studies On The Physiological Characters And Ethanol Fermentation Of Post-harvest Sweet Sorghum Stalk

The new sorghum No.3 and No.4 sweet sorghum stalk selected by Xinjiang Academy of Agricultural Science were used as the trial material, and their physiological parameters content, including water, total sugar, reduce sugar, total acidity, starch,fiber,dehydration rate, respiration rate, Sucrose Synthase(SS) and Sucrose Phosphate Synthase(SPS) activity were studied under different storage conditions (defoliation stand, defoliation lie, leaf stand, leaf lie, pyramid type) both in different growth periods(jointing stage, maturity stage,full ripeness stage) and in 220 days storage periods. Fermatation technology also were studied.The results showed that: in different growth period: the parameters above except the SS and SPS activity showed an increasing tendency during the whole growth periods, the increasing rate was significantly from the jointing stage to the maturity stage.however both SS activity and SPS activity were lowest in maturity stage, and highest in jointing stage. The parameters tested of No.3 new sorghum were significantly higher than No.4 new sweet sorghum during the whole growth periods. During whole storage period: the parameters above except reduce sugar and total acidity content, dehydration rate, respiration rate showed a decreasing tendency, and the reduce sugar content showed a"double peak"tendency upon the whole storage method.The parameters tested except dehydration rate, respiration rate of No.3 new sorghum were significantly higher than No.4 new sweet sorghum. As the storage time goes on, the content of parameters except the total acidity, dehydration rate, respiration rate from highest to lowest was defoliation stand-defoliation lie-leaf stand-leaf lie- pyramid type 5th- pyramid type 4th- pyramid type 3rd- pyramid type 2nd - pyramid type 1st in the whole storage period,while dehydration rate showed the opposite tendency. Respiration rate of the whole stalk types was higher than the pyramid type during the whole growth periods. the Total acidity content of pyramid type was higher than the whole stalk types during the whole storage period, in 0-130 d total acidity content showed an increasing tendency, and in 130-220 d the whole stalk types showed a decreasing tendency while the pyramid type showed an decrease- increase tendency.The optimal Solid- State fermentation condition for the sweet sorghum stalk are: inoculum 5 %(v/w), fermentation time 48 h,temperature 30℃, the sweet sorghum stalk water ratio 14:1, pH 4.0, 0.3 %(NH₄)₂SO₄,0.2 %KH₂PO₄,0.1 %MgSO₄,0.1 % cellulase, 0.08 % glucoamylase,the ethanol yield can reach to 7.2%(v/v).