The invention belongs to the technical field of biological agents, and discloses a concentrated
lactulose solution and a preparation method thereof.The preparation method comprises the steps that
purified water and
lactose are mixed and stirred to be uniform, then
sodium metaaluminate is added, a heat preservation reaction is conducted till the
lactose content is smaller than 9%, and then cooling is conducted; adjusting the pH value to 4-7 to obtain a
lactulose-aluminum
hydroxide flocculation mixed
system; adding
purified water into the mixed
system, uniformly stirring, then adding
polyaluminum chloride, uniformly stirring, and standing; carrying out residue-liquid separation on the obtained
system, and collecting filtrate; desalting the filtrate until the
conductivity is less than or equal to 50 [mu] s / cm, and concentrating to obtain a concentrated
lactulose solution meeting the medicinal-grade standard. The problems of aluminum
hydroxide precipitation, difficult
filtration and low removal efficiency in the prior art are solved by using the
polyaluminum chloride, the
aluminum ion removal efficiency is higher, the purification operation step is greatly simplified,
nanofiltration and resin operation are replaced by one-step
electrodialysis desalination, the use of a large amount of
purified water and the generation of aluminum salt
wastewater are reduced, and the method is suitable for industrial production. The process steps are simplified, the cost is reduced, and the quality is controllable.