METHOD OF PRODUCING .ALPHA.,.ALPHA.-TREHALOSE

摘要

The method for producing crystalline .alpha.,.alpha.-trehalose by isolation from baker's yeast consists in the extraction of baker's yeast with ethanol of concentration 70 to 96 volume %, vacuum concentration of the obtained extract to the concentration of .alpha., .alpha.-trehalose 2 to 30 weight %, after removing the solid portion by filtration, and of the following membrane filtration process consisting of ultrafiltration through an ultrafiltration membrane with the separation limit of molecular masses higher than 500 and, if desirable, of the preceding microfiltration through a microfiltration membrane with the mean pore diameter ranging from 0.05 to 5 .mu.m, preferably from 0.05 to 0.15 .mu.m, where the obtained clear solution, after decolourizing with activated charcoal, is brought into contact with an ion exchanger in H+ cycle and then with an ion exchanger in OH- cycle and the resulting demineralized solution is concentrated in vacuum to the concentration of 40 to 85 weight % and .alpha.,.alpha.-trehalose crystallizing, after addition or ethanol in the amount of 0.5 to 1.5 parts per part of .alpha.,.alpha.-trehalose, is isolated and recrystallized from ethanol after repeated demineralization. Another object of the method according to the invention consists in carrying out the continuous ultrafiltration through an ultrafiltration membrane with the separation limit of molecular masses higher than 500 and, if desirable, carrying out the preceding microfiltration through a microfiltration membrane with mean pore diameter ranging from 0.05 to 5 .mu.m, preferably from 0.05 to 0.15 .mu.m. In the method carried out according to the invention, a styrenedivinylbenzene copolymer with strongly acid sulfo groups is used as a cation exchanger and a styrene-divinylbenzene copolymer with quaternary dimethylhydroxyethylammonium exchanging groups as an anion exchanger. Disaccharide .alpha.,.alpha.-trehalose produced by the method according to the invention is an important raw material or intermediate in pharmacy, food industry and biochemial research.