Determination of Dietary Fiber and Carbohydrate Composition of Foods by a Modified Version of the Englyst Method

Abstract

A modified version of the Englyst procedure for determination of dietary fiber and carbohydrate fractions of foods is described. The method is based on hydrolysis of separated fractions and capillary gas chromatographic (GC) analysis of derivatized monomer sugars, UV photometry of uronic acids, gravimetric determination of residue, and analysis of nitrogen content of the residue by using a C, H, N elemental analyzer. Modifications of fractionation, derivatization, and GC procedures are discussed. Rigorous sample preparation is required for reproducibility of 200 mg test portions. Contami- nants interfering with chromatography must be minimized. Results for reference samples (wheat bran and Buerre Bosc pears) and white and wholemeal bread agree with literature values.