| 摘要 |
501,542. Glutamic acid. STANDARD BRANDS, inc. Aug. 31, 1937, No. 23848. Convention date, Sept. 2. 1936. [Class 2 (iii)] Glutamic acid is prepared by mixing undried wheat gluten with so much concentrated hydrochloric acid that an approximately 10 per cent solution thereof is formed in the resulting mixture which is heated to give glutamic acid until sufficient of the hydrogen chloride has combined with the reaction products to reduce the concentration of the former to about 4 per cent, glutamic acid then being recovered. Wet wheat gluten containing about 66 per cent water is mixed with <2>/5ths. of its weight of about 30 per cent hydrochloric acid giving a final concentration of about 10. per cent. The mixture is heated for about 6 hrs. at 125‹ C. and 20 lb. / in<2>. The glutamic acid, other amino-acids, and ammonia formed combine with part of the hydrochloric acid, the resulting concentration of which is about 4 per cent. The product is filtered, the filtrate preferably extracted with, e.g., benzene or carbon tetrachloride, and treated with decolorizing carbon, and then heated, preferably under reduced pressure, to distil free HCl and water in the form of a constant-boiling acid which can be used for treating more gluten. The syrupy residue can be mixed with concentrated hydrochloric acid and cooled to 0‹ C., .when glutamic acid hydrochloride crystallizes. The mother liquid can be further worked up if desired. The free acid or its salts are obtained in known manner.
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