Patent GB-695378-A (GB)
Title: Process for the production of solutions of amino acid mixtures having a high cystine content
IPC: A23J3/32
Filed: 1950-08-11
Abstract: Solutions of amino acids having a high cystine content are prepared by hydrolysing keratins with the aid of sulphuric acid and/or hydrochloric acid, mixing the resultant hydrolysate containing free mineral acid with an amount of d-glucose or dextrose corresponding to about 14-16 times the cystine content of the hydrolysate and then neutralizing the free mineral acid. In a modification an amount of starch is added to the hydrolysate which is then heated, whereby the starch is hydrolysed to provide in situ the desired amount of sugar. Neutralization is generally effected with basic alkaline earth metal compounds.  The hydrolysate containing sulphuric acid may be neutralized with a keratin hydrolysate prepared using a basic alkaline earth metal compound as hydrolysing agent.  Part of the sulphuric acid may be neutralized with a basic alkaline earth metal compound and the remainder with an alkaline earth metal thiocyanate yielding thereby a solution of amino acids, the sugar and thiocyanic acid useful as a disinfectant and as an impregnator for bandages (see Group VI).  In typical examples: (1) cleaned hair is hydrolysed by boiling with aqueous hydrochloric acid, treated with charcoal, filtered, boiled with the appropriate amount of starch and then neutralized with ammonia and calcium carbonate; (3) cleaned hair is hydrolysed with aqueous sulphuric acid in presence of charcoal, filtered and boiled with starch; a second quantity of cleaned hair is hydrolysed with aqueous strontium hydroxide and filtered; the two hydrolysates are then mixed and the neutralization of the sulphuric acid completed with strontium carbonate; (4) cleaned hair is hydrolysed with sulphuric acid and the hydrolysate boiled with starch as in (3) and the mixture neutralized with a mixture of strontium carbonate and thiocyanate and filtered.ALSO:Amino acid solutions, suitable for enrichment of inferior nutrition albumen, for producing nutrient media for bacteria and, in conjunction with thiocyanic acid, useful as disinfectants are prepared by hydrolyzing keratins with the aid of sulphuric and/or hydrochloric acid, mixing the resulting hydrolyzate containing free mineral acid with an amount of d-glucose or dextrose corresponding to about 14-16 times the cystine content of the hydrolyzate and then neutralizing the free mineral acid.  In a modification, starch is used in place of dextrose or glucose and the solution is heated to form in situ the sugar in required amount. Neutralization is effected with basic alkaline earth metal compounds; thus, the acid hydrolyzate may be mixed with the hydrolyzate obtained by hydrolyzing keratin with the basic alkaline earth metal compound. The thiocyanic acid may be added as such to the neutralized hydrolyzate or added to the partially neutralized hydrolyzate in the form of an alkaline earth metal thiocyanate; the solution, thickened if desired by addition of silica gel, may be used to impregnate bandages.  In typical Examples: (1) cleaned hair is hydrolyzed with aqueous hydrochloric acid, the hydrolyzate is then boiled with starch and neutralisation effected with ammonia and calcium carbonate; (2) clean hair is hydrolyzed with aqueous sulphuric acid and boiled with starch, the resulting solution is mixed with a hydrolyzate obtained by boiling with aqueous strontium hydroxide and neutralization of the mixture completed with strontium carbonate; (3) cleaned hair is hydrolyzed with aqueous sulphuric acid, boiled with starch and neutralized with a mixture of strontium carbonate and thiocyanate.