Take the Pure L Glutamine fermentation broth and microfilter it through a ceramic membrane (0.3μm pore size, microfiltration pressure 2.0-3.5MPa) at 28°C. The liquid is concentrated at 37°C to 16.7% of the volume of the filtrate, that is, the concentration ratio is 6 times. The obtained concentrated liquid is cooled to below 10°C to crystallize, and then undergoes plate and frame dehydration (the plate and frame filter pressure is 0.4-0.8MPa, and the water injection pressure 1.4MPa) to obtain the first Pure L Glutamine crude product and filtrate, and the filtrate was sent to prepare compound fertilizer;
Add water to the crude L-glutamine, adjust it to a suspension with a mass percentage of 25%, and then go through plate and frame dehydration again (the conditions are the same as above), separate and obtain the second Pure L Glutamine crude product and mother liquor, and the mother liquor is for use; the second Pure L Glutamine Add water to the L Glutamine crude product to adjust it to a solution with a mass percentage of 5%, and then add activated carbon for decolorization. The amount of addition depends on the actual color of the suspension. 16.7%, that is, the concentration ratio is 6 times. The resulting concentrated solution is cooled to below 5°C to crystallize, and then centrifuged to obtain the finished L-glutamine product and the refined mother liquor. The refined mother liquor is used for later use.
After HPLC detection, the yield of Pure L Glutamine was 55%, and the purity was above 98.5%. At the same time, the same source and weight of L-glutamine fermented liquid were used to extract the traditional method, and the final obtained L-glutamine was detected, and the yield was 53%, and the purity was above 98.5%, and there was no significant difference between the two. Sexual difference shows that the extraction method described in this method can guarantee product quality on the basis of saving procedures.