Chemical Constituents of Five Northeastern Barks

A study was undertaken to characterize the major chemical constituents of five barks common to northeastern United States. The species examined were white pine (Pinus strobus), red pine (P. resinosa), shagbark hickory (Carya ovata), red oak (Quercus rubra), and red maple (Acer rubrum). Chemical analysis results showed that both within species and among species variation in ash, ethanol-benzene extractives, and suberin content occurred among the species examined. Significantly higher alcohol-benzene extractive and suberin contents were measured in shagbark hickory bark compared to the other barks examined in this study.Both within species and among species differences in holocellulose content were measured. In general, a higher holocellulose yield was obtained from hardwood bark compared to softwood bark, with the exception of red maple bark. With but one exception, no within species differences in Klason lignin content and aromatic content were detected. However, statistical differences were measured among the species examined. In general, the softwood species contained a higher aromatic content and Klason lignin content than did the hardwood barks examined in this study