Patent GB-345250-A (GB)
Title: Improvements in and relating to the recovery and purification of alkaloids from cocoa products
IPC: C07D473/10
Filed: 1929-10-07
Abstract: Theobromine and caffeine.-Cocoa products are subjected, in aqueous suspension, to the action of a mineral acid such as sulphuric, hydrochloric or phosphoric acid or an acid anhydride such as sulphur dioxide preferably at the boiling point.  An alkaline substance such as lime or other alkaline earth oxide or hydroxide is then added in quantity at least sufficient to neutralize the acidity and after the solid cocoa material has been separated, the alkaloids are recovered from the resulting liquors. The acid treatment may also be carried out at higher temperatures under pressure.  If just sufficient lime &c. has been added to neutralize the acidity, additional alkali in the form of a weak base such as ammonium hydroxide may be added. When excess of alkali has been used, the solids may be separated by filtration and theobromine may be precipitated from the filtrate by the addition of substances such as hydrochloric acid; carbon dioxide may also be used, the liquid being filtered hot from the precipitated calcium carbonate, theobromine crystallizing on cooling.  As this precipitation of calcium carbonate has a purifying action, sodium carbonate or the like can be added to the extract before or after the addition of carbon dioxide to produce further calcium carbonate by reaction with the soluble calcium salts present.  The mother liquor remaining after the separation of the theobromine may be evaporated and a second crop of theobromine crystals thus obtained.  The second mother liquor may be treated for the recovery of caffeine, for example by extraction with organic solvents such as benzol.  The impure second crop of theobromine crystals may be purified by treating an aqueous solution thereof with calcium or alkali hydroxide, and precipitating theobromine by acidification after filtering the solution; or the solution may be treated with an alkali carbonate such as sodium carbonate and filtered from the resulting alkaline earth carbonate before acidification.  The extracted liquors may be mixed with the separated solid cocoa material, the wet material being directly used as a fertilizer, or it can be dried and ground and used as a fertilizer or cattle food.  The drying is preferably done by means of the gases as their carbon dioxide content neutralizes the free lime in the material.ALSO:Cocoa products are subjected, in aqueous suspension, to the action of a mineral acid such as sulphuric, hydrochloric or phosphoric acid, or an acid anhydride such as sulphur dioxide preferably at the boiling-point. An alkaline substance such as lime or other alkaline-earth oxide or hydroxide is then added in quantity at least sufficient to neutralize the acidity and after the solid cocoa material has been separated, the alkaloids are recovered from the resulting liquors.  The extracted liquors may be mixed with the separated solid cocoa material, the wet material being directly used as a fertilizer, or it can be dried and ground and used as a fertilizer or cattle food.  The drying is preferably done by means of flue gases as their carbon dioxide content neutralizes the free lime in the material.