Effects of Secondary Metabolites from Balsam Poplar and Paper Birch on Cellulose Digestion

Abstract

Inhibitory effects of metabolites from balsam poplar (Populus balsamifera) and Alaskan paper birch (Betula papyrifera) on cellulose digestion in vitro were examined. Significant inhibition of cellulose digestion occurred at concentrations of 5 mg per gram of substrate for benzyl alcohol, cineole, papyriferic acid, and a steam distillate fraction from juvenile paper birch. Digestibility declined as increasing amounts of resin were added to the substrate, but the rate of inhibition declined with each concentration increment. Secondary metabolites present in resins of paper birch and balsam poplar appear to be important in determining the relative nutritive quality of these species.