Novel method for crystallizing L-phenylalanine

Abstract

The invention discloses a novel method for crystallizing L-phenylalanine. The method comprises the following steps of: slowly feeding hydrochloric acid into alkaline L-phenylalanine solution with the pH of between 10.0 and 12.0 with stirring at the temperature of between 37 and 45 DEG C to lower the pH value of the solution; when the pH of the solution is lowered to 5.0 to 6.0, cooling a crystallization system; performing suction filtration; washing crystals with ethanol; and performing vacuum drying to obtain alpha type L-phenylalanine crystals. By controlling a crystallization process condition, the alpha type L-phenylalanine crystals with uniform size and transparent color and without special smell can be obtained. The method is easy to operate, has high repeatability, is relatively environmentally-friendly because an organic solvent is not added, and is suitable for industrial crystallization of the L-phenylalanine.

Description

A new method for crystallization of L-phenylalanine technical field The invention belongs to the technical field of separation and purification engineering, and relates to a new method for producing high-purity α-type L-phenylalanine crystals through reaction crystallization of L-phenylalanine solution after ion exchange, decolorization and concentration. Background technique L-phenylalanine is an essential amino acid that cannot be synthesized by the human body and has important physiological activities. The amino acid is mainly used for: (1) as a raw material for the synthesis of food additives, for example, the main raw material of aspartame, the most popular low-calorie health-care sweetener, is L-phenylalanine; (2) as a medical raw material, Such as amino acid infusion, intermediates of amino acid anticancer drugs, and L-phenylalanine is also a raw material for the production of epinephrine, thyroxine and melanin. L-phenylalanine is a polymorphic substance, which ha...

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Problems solved by technology

People such as Han Wei (Han Wei, Deng Xiu, Ma Xinsheng, Dai Gance, Shi Yajun. Liquid membrane method extracts the phenylalanine in the fermented liquid, East China University of Science and Technology Journal [J], 997,23 (12), 669-673) adopt Isoelectric point crystallization method Dissolve L-phenylalanine in hydrochloric acid solution, add salting-out agents such as sodium chloride or ethanol, and add NaOH particles at the same time, control the crystallization temperature and stirring speed to obtain α-type L-benzene Alanine crystals, but this method is because L-phenylalanine has a certain coating on sodium chloride or ethanol, resulting in impure crystals, and the highest yield can only reach 78%, which cannot meet the requirements of the industry

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