Abstract

As part of a study on the potential of waste wood from pruning for use in the paper and pulp industry, lignin was extracted from black currant (Ribes nigrum) by ball-milling debarked stems in 90% dioxane. The preparation was digested with Driselase before being extensively washed with water and diethyl ether. The lignin was characterized by both 13C NMR and FT-IR which showed that both 4-hydroxy-3-methoxy (guaiacyl) and 3,5-dimethoxy-4-hydroxy (syringyl) substituted aromatic rings were present in roughly equal amounts, indicative of hardwood lignin. 13C NMR also established the presence of 5-5'-, -O-4- and -5-linkages. A small amount of carbohydrate (1-2%) was present, which was found to contain xylose and mannose in the ratio 3:1, a result similar to that found for hardwood lignins prepared in a similar way. All results confirm that black currant stem wood is a typical hardwood.