Kraft Cooking with Teak Wood Extract and Determining Residual 2-Methylanthraquinone in Eucalyptus Pulp

抄録

Anthraquinone（AQ）is used in the pulp and paper industries as a cooking catalyst. However, because AQ is “possibly carcinogenic”, it is no longer approved in Germany for the manufacture of paper and paperboard that contact food. To address this problem, we examined 2-methylanthraquinone（2-MAQ）, a natural anthraquinone from teak（Tectona grandis）wood. Eucalyptus globulus wood was subjected to kraft cooking at 145℃ for 3 h with 0.03％2-MAQ and 15-19％ active alkali to provide pulp in 55.5-58.1％ yield. Kraft cooking with the acetone extract of Myanmar teak wood increased pulp yield by 1.6％ but decreased kappa number by two points compared to that with only 2-MAQ. Ames testing suggests that 2-MAQ is not mutagenic. Unbleached and oxygen-bleached pulp contained 0.40- 2.90 ppm and 0.21-0.39 ppm residual 2-MAQ, respectively, while 2-MAQ was not detected in fully bleached pulp; therefore, this pulp should be safe for food-packaging use.