All previous methods of birch bark extraction were focused mainly on the use of different solvents (polar and non-polar). The yield of betulin by different solvent extraction methods from Betula papyrifera did not exceed 10-11% on dry outer bark. We have found it is possible to increase the yield of betulin by 80% (from 10% to 18%) by developing depolymerization/extraction technology. Depolymerization (hydrolysis) of birch bark’s natural polymer suberin releases the bound portion of betulin and suberinic omega-hydroxy fatty acids. Unbound and released betulin is extracted efficiently from hydrolyzed mass with an 18% yield. Salts of suberinic and betulinic acids represent another valuable product of this technology.
From 1,000 lbs. of the outer birch bark (Betula paperifera), 180 lb of betulin + 650 lbs. of birch bark soap (sodium salts of suberibic fatty acids with 6% of betulionic acid salt) could be obtained. Acidification of these salts gives 530 lbs. of suberinic fatty acid, including 10% of betulinic acid. Sodium or potassium salts of birch bark suberinic fatty acids or suberinic fatty acids has high potential for use in washing materials, cosmetics, shampoos, skin care products, hair care products, nutraceuticals and cosmeceuticals. Thus, nearly 70% of commercially and industrially valuable materials could be produced from 1,000 lbs. of outer birch bark.
The Chemical Extractives Laboratory is ready to provid interested industrial partners with additional information about depolymerizing/extraction technology of birch bark processing and samples of birch bark products. With the use of pilot equipment the lab can provide customers with pilot scale amount of samples (1-10 lbs.) for broad tests or market development. Any possible chemical derivatives of birch bark products also may be synthesized at laboratory and pilot scale for interested partners and customers.