Soybean seeds and its by-product okara as sources of dietary fibre. Measurement by AOAC and Englyst methods

Araceli Redondo-Cuenca; Ma José Villanueva-Suárez; Inmaculada Mateos-Aparicio

doi:10.1016/j.foodchem.2007.11.061

Soybean seeds and its by-product okara as sources of dietary fibre. Measurement by AOAC and Englyst methods

Food Chem. 2008 Jun 1;108(3):1099-105. doi: 10.1016/j.foodchem.2007.11.061. Epub 2007 Dec 3.

Authors

Araceli Redondo-Cuenca¹, Ma José Villanueva-Suárez², Inmaculada Mateos-Aparicio²

Affiliations

¹ Dpto. Nutrición y Bromatología II: Bromatología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain. Electronic address: arared@farm.ucm.es.
² Dpto. Nutrición y Bromatología II: Bromatología, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.

PMID: 26065777
DOI: 10.1016/j.foodchem.2007.11.061

Abstract

The composition of soybean seeds and its by-product okara has been studied in this work. Dietary fibre was analysed by Englyst et al. method, by enzymatic-gravimetric methods of AOAC and by the quantification of the monomers obtained from the AOAC residues after acid hydrolysis (AOAC plus hydrolysis). Total dietary fibre by the enzymatic-gravimetric methods of AOAC in okara (55.48g/100g dry matter) is more than twice that of soybean seeds (24.37g/100g dry matter). The proportion IF/SF is 11 in okara and 6 in soybean seeds. Dietary fibre results from enzymatic-gravimetric AOAC methods are higher in okara and soybean seed samples than those from the Englyst method (okara: 41.14g/100g dry matter; soybean seeds: 15.05g/100g dry matter), and AOAC plus hydrolysis (okara: 44.91g/100g dry matter; soybean seeds: 16.38g/100g dry matter). In the case of the insoluble fibre from both samples, AOAC plus hydrolysis gives significantly (p<0.001) higher values than the Englyst method, whilst for soluble fibre the opposite occurs (p<0.001). The main monomers in soybean seeds and okara fibre are glucose, galactose, uronic acids, arabinose and xylose. The proportion of each monomer is similar in soybean seeds and okara, so the healthy properties of soybean seeds fibre are also claimed for okara.

Keywords: Dietary fibre; Non-starch polysaccharides; Okara; Soybean seeds.