| 摘要 |
FIELD: chemistry.SUBSTANCE: method of pectin extraction with high degree of polymerisation includes addition of oxalic acid and/or water-soluble oxalate in water suspension which contains peel pectin. Oxalic acid and/or water-soluble oxalate is added until mixture with pH in the range between 3.0 and 3.6 is obtained. The total molarity of oxalate must be more than the total molarity of calcium (II) in peel. Then mixture is heated to temperature from 50 to 80°C for the time, sufficient for pectin extraction. Then extracted pectin is separated from mixture by sedimentation. In other version of method after heating mixture is subjected to unessential filtering to remove insoluble solid substances and then mixture is brought in contact with cation-exchange resin. Extracted pectin is separated from mixture by sedimentation with obtaining pectin output relative to peel more than 23%. Output of pectin (Y) is evaluated by formula Y=0,1·y·M/W(I), where yrepresents output of liquid extract in g/kg, M represents the total mixture weight before separation of extracted pectin and Wrepresents weight of peel applied in water suspension. Invention makes it possible to obtain pectin with degree of etherification (DE), at least, 72, high degree of polymerisation and intrinsic viscosity higher than 6.5 dl/g.EFFECT: increase of polymerisation degree and viscosity.20 cl, 7 dwg, 3 tbl, 4 ex |
