High-humidity performance of paperboard after treatment with xylanase, endoglucanse, and their combination.

For paperboard used to produce packaging, treatment of its fiber constituents with commercial enzymes can improve its compressive strength under cycling and high-humidity conditions. Xylanase that selectively removes pulp xylan (ca. 2% of the pulp by mass) yielded most of the observed beneficial effects, which did not appear related to the packing of the fiber network in the sheet or to the uptake of moisture at high humidity.