GB766685A - Improvements in or relating to process for the recovery of glutamic acid - Google Patents

Abstract

Glutamic acid is obtained by hydrolysing precursors thereof, neutralizing the hydrolysate with an agent which forms an insoluble salt with the hydrolytic agent, separating off the salt, adjusting the pH of the filtrate to 2.5-4.0 with sulphuric acid, crystallizing out glutamic acid, adjusting the pH of the mother liquor to 1.0-3.5 with sulphuric acid, adding sufficient methanol to precipitate ash-forming material and crystallizing glutamic acid from the filtrate at its isoelectric point. The latter step is facilitated by passing the solution through a cation or anion exchanger, subsequently eluting the adsorbed glutamic acid and crystallizing it at pH 2.5-4.0. The process is applicable to the treatment of desugarized beet molasses or proteinaceous materials such as gluten. Hydrolysis may be effected with barium or calcium hydroxide and the metal subsequently precipitated at pH 6-10, preferably 7-10, with carbon dioxide, sulphur dioxide (or salts thereof) or sulphuric acid. It is advantageous to bring the pH first to 4.5-5.5 and concentrate and filter the solution before the final adjustment of the pH. An example is given of the process. Specifications 655,841, 742,497 and U.S.A. Specification 2,586,295 are referred to. Reference has been directed by the Comptroller to Specification 644,382.