Dietary Fibre Content and Composition of Some Edible Fungi Determined by Two Methods of Analysis

Abstract

Six common edible fungi from four orders of Basidiomycetes, namely Agaricus bisporus (Agaricales), Auricularia auricula and Auricularia polytricha (Auriculariales), Tremella fuciformis (Tremellates), Ganoderma lucidum and Poria cocos (Aphyllophorales), were analysed for their total dietary fibre (TDF) content using the Association of Official Analytical Chemists (AOAC) method and for dietary fibre content and composition using the Uppsala method. The non-protein nitrogen contributed from fungal chitin was corrected in the fibre residue obtained by the AOAC method. The TDF content measured by the AOAC method was always greater than that of the Uppsala method. The TDF content determined by the AOAC and Uppsala methods ranged from 182 and 132 g kg-1 (dry matter) in A bisporus to 735 and 711 g kg-1 (dry matter) in P cocos, respectively. Neutral and amino sugars were the dominant sugars in all the fungi. Sugar composition of the TDF reflected that the major cell wall polysaccharides in most fungi were hemicelluloses, such as β-glucan and glucuronoxylomannan, pectic substances and chitin. Judging from their high fibre content and unique fibre composition, edible fungi have considerable value as sources of dietary fibre in human nutrition. © 1997 SCI.