GUANINE PRODUCTION METHOD Russian patent published in 2015 - IPC C09D5/36 C07D473/18 

FIELD: food industry.

SUBSTANCE: invention relates to fish industry, particularly to extraction of guanine from silvery scale and skin of individual fish species used during production of pearl paste and a mother-of-pearl preparation. The guanine production method involves guanine removal and cleaning of protein and lipid impurities; the raw material is represented by air-cured Caspian roach skin with scale; guanine removal is performed by way of such skin soaking in 10% water solution of carbamide with the mixture heated to 45°C at a ratio of 1:10 and maintained under the ambient temperature during 60-72 h; the produced mixture is filtered and washed with water with further cleaning of guanine by way of introduction of the trypsin enzyme with concentration equal to 0.3% and creation of a slightly alkaline medium through addition of 0.0125% water solution of a laundry soap surfactant with pH equal to 7.8-8, the ratio to the initial guanine weight equal to 1:1.5; the mixture is fermented at a temperature of 37°C during 24 hours, with guanine washed with water, degreased with acetone and isolated.

EFFECT: guanine yield increase.