Xylanase Treatment Suppresses Light- and Heat-Induced Yellowing of Pulp

Abstract

Xylanase is commonly applied in pulp and paper industries to ease cost-related and environmental pressures. The effect of xylanase treatment on pulp bleaching is well-established, however, few studies were conducted on the effects of xylanase treatment in pulp yellowing, especially the mechanism of pulp yellowing inhibition by xylanase treatment. In this study, pure xylanase (EC 3.2.1.8) was applied to treat wheat straw chemical pulp (CP) and poplar chemi-thermo-mechanical pulp (CTMP) to determine their effects on pulp brightness and on light- and heat-induced yellowing. The xylanase treatment decreased the post-color number of the pulps during light- and heat-induced yellowing. However, differences were observed in the yellowing inhibition between the wheat straw CP and poplar CTMP. The changes in chemical components of pulps after the xylanase treatment, for example, lignin, hemicellulose, and HexA contents, and analysis of UV–vis absorption spectra and Fourier transform infrared-attenuated total reflectance spectrum were used to explore the pulp yellowing inhibition causes by the xylanase treatment.

Fusarium concolorX4 Pretreatment Suppresses Light-Induced Yellowing of High-Yield Pulp

“…e decrease of signal (▽K/S) at 240 nm and 280 nm after biotreatment (Figure 3) might be caused by the decrease of HexA content in biotreated pulp ( Table 2). at HexA (240 nm) was easier to be degraded to the UV-active compounds (280 nm) and then transformed to colored structures during light-induced yellowing, which is consistent with the previous research results [42,43]. F. concolor X4 treatment degraded HexA or changed HexA structures, thus blocking the transformation process of HexA to chromophores.…”

Optimization and Analysis of Transparent Bamboo Performance Using Response Surface Methodology (RSM) and Linear Analysis Method

“…This will also lead to the L decrease. [27] 3) Besides lignin, the yellowing problem of epoxy resin may also cause the L decrease. [28] In addition, the tensile strength of TB-12 was also excellent (119.3 MPa), which was bet- ter than high strength TB materials reported in the reference (92 MPa).…”