Release of chromophores and reducing sugars
During pulp treatments, enzyme-mediated release of chromophoric
material was monitored in filtrates by measuring absorption
spectra (Lambda-5 UV/VIS Spectrophotometer, Perkin-Elmer) at
237, 254, and 280 nm. Reducing sugar concentrations in pulp
filtrates were determined by the dinitrosalicylic acid (DNS)
method14 and expressed as d-xylose equivalents. After enzyme
and control treatments, the pulps were thoroughly washed with
deionized water and processed for chemical bleaching as described
below.