Study On Techhics Of Drying Terder Stalk And Frondge In Fructus Lycii

To study L.barbarum L of physical and chemical component and drying process,were confirmed the optimum technics of hot air drying,vacuum drying and vacuum freeze-drying drying process,the color of products is fresh green,less loss of nutrition,rehabilitation of water rate is high.So far,there is no publicly report of the drying process and technology of L.barbarum L at home and abroad.(1) by 0.04%Zn(CH₃COO)₂ and 0.02%Na₂SO₃ mixed solution as the hot air drying and vacuum freeze-drying of the green-maintaining reagent,the result prove that green-maintaining good for zinc and copper in color,but also can be well protected vitamin C.Raw materials will be in 95 100°C solution of the green-maintaining blanching 100 s can be better green-maintaining effect of hot air drying and vacuum freeze-drying process; Vacuum drying process used in microwave firepower 100%to fixing 60s,after dip in the green-maintaining reagent for 30 min.The method can reduce the drying time of green-maintaining and get better results.(2) Blanching have a great influence in color and nutrients of the L.barbarum L,the test results proved that the high temperature and short-time(blanching temperature≥90℃, blanching time≥90 s) can unwork of POD.Extended operating hours can reduce the vitamin C and carotene losses.Liquid-pH value of 6.5,the chlorophyll retention rate is the largest;By 0.3%the hardening of immersion 20 min after blanching,the organization can improve. Determine appropriate blanching process parameters are:blanching temperature of 95 100℃,blanching time for the 100 s.(3) By 4%of the sucrose solution or 10%of the dextrin solution or 3.5%of the salt solution bleaching products can increase the dry-water rate,by contrast tests proved that by 4%of the sugar solution soak 30 min can improve the dry-water rate.(4) The hot air drying process optimization of the L.barbarum L:blanching temperature of 95 100℃,blanching time for the 100 s,for color selection of 0.04%Zn (CH₃COO)₂,0.02%Na₂SO₃ and composition of the mixed green-maintaining agents,drying temperature of 85℃;vacuum drying of the optimization process:green-maintaining 100% microwave method used under fire,60 s fixation,and then 0.02%NaHCO₃ solution soak 20 min;drying oven temperature to 75℃,vacuum degrees for 0.08 MPa;vacuum freeze-drying process for the optimization:at 95 100℃,blanching 100 s,using 0.04%Zn(CH₃COO)₂ and 0.02%Na₂SO₃ composed of a mixed solution of green-maintaining solution,pre-cooling temperature was -25℃,vacuum degree was1 5 Pa,drying temperature was -45℃.