Structural Characterization and Pyrolysis Characteristics of Lignin in Traditional Smoked and Roasted Wood

In order to explore the effects of different wood types with different chemical compositions and structures on the types and amounts of polycyclic aromatic hydrocarbons produced in traditional smoked meat products, the structural and pyrolysis characteristics of lignin in five kinds of wood commonly used in the production of traditional smoked and roasted meat products, pine, poplar, beech, jujube and apple wood, were investigated by infrared spectroscopy, Raman spectroscopy, thermogravimetry and thermogravimetry coupled with infrared spectroscopy. The results showed that there were differences in the contents of lignin, guaiacyl (G) and syringyl (S) in the five kinds of wood. The pyrolysis process involved three stages, mainly in the range of 200?500 ℃, but the mass loss rate, mass loss temperature, pyrolysis rate and pyrolysis temperature of lignin were different among different kinds of wood, indicating that there are significant differences in the thermal stability of lignin from different wood sources. Differences in lignin content, S/G structure content and side chain structure in smoked and roasted wood could lead to different thermal stability, and different pyrolysis characteristics could in turn affect the formation of harmful substances such as polycyclic aromatic hydrocarbons.