METHOD OF PROTEIN HYDROLYSATE PREPARING Russian patent published in 1994 - IPC

FIELD: chemical technology. SUBSTANCE: hydrothermal treatment of leather waste is carried out at pH 12-13 with alkaline mixture consisting of calcium hydroxide and sodium carbonate at their mass ratio 1.0:(1.4-1.5), respectively, at 125-130 C for 35-45 min at the first stage and at 105-110 C for 15-25 min at the second stage following by recuperation of chrome tanning agent components from the slime with concentrated sulfuric acid at volume ratio acid : slime = (0.2-0.3):1.0 for 25-30 min at pH 1.5-1.7. Yield is 90.1% , chrome Cr⁺³ content is 0.48 mg/kg protein hydrolysate. Product is used as component in cosmetic agents and domestic chemistry preparations. EFFECT: improved method of preparing, increased yield of product. 2 tbl