CP-MAS NMR analysis of carbohydrate fractions of soybean hulls and endosperm

Abstract

CP-MAS NMR spectroscopy was used to identify soybean cellulose and pectin extracts and to investigate the kinetics of cross polarization. The in vitro incubation of cellulose and pectin, extracted from soya hull and endosperm, respectively, with sheep rumen fluid was followed with this technique. The difference in enzymatic degradability between ChSS and DASS, two pectins with identical monosaccharide composition, was explained by the degree of esterification that is lower in DASS. Variable contact time CP-MAS NMR experiments of the cellulose fraction during the incubation revealed that cellulose was degraded in a layer-by-layer way.