On the importance of lignin-carbohydrate complexes in wood and chemical pulps

Selective enzymatic hydrolysis of cellulose has been used to facilitate the isolation of lignin-carbohydrate complexes from wood and kraft pulps. On isolated fractions, a combination of thioacidolysis and size exclusion chromatography was used to gain information about the structure and chemical changes taking place in the lignin component when going from wood to kraft pulp. The method has been applied to spruce, birch and eucalyptus. For the hardwoods, however, the method needs improvement.