Quantitative evaluation of 1,3,1,6 β-D-glucan contents in wild-growing species of edible Polish mushrooms

Background: Macrofungal β-glucans are mainly represented by compounds with β-1,3- and β-1,6 glycosidic bonds. They have been shown to have immunomodulatory, anticancer, and antioxidant properties. Although there are many reports on the bioactivity and structure of fungal glucans, studies on the quantitative assessment of these compounds are sparse.

Objective: The aim of the study was to determine total β-glucans and 1,3-1,6-β-D-glucan contents in selected species of wild-growing edible Polish mushrooms.

Material and methods: Eight species of wild-growing edible mushrooms Boletus pinophilus, Hydnum repandum, Craterellus cornucopioides, Suillus variegatus, Suillus granulatus, Gyroporus cyanescens, Tricholomopsis rutilans, and Auricularia auricula-judae and one species of cultivated mushroom for comparison purposes Agaricus bisporus, were analyzed. Quantitative analysis of 1,3-1,6-β-D-glucans was done using a colorimetric method in accordance with Nitschke et al.

Result: Mean total β-glucan content varied from 13.5 g/100 g dry mass in A. bisporus (portobello variety) to 40.9 g/100 g dry mass in T. rutilans. Mean 1,3-1,6-β-D-glucan content in the analyzed fruiting bodies ranged from 3.9 g/100 g dry mass in Agaricus bisporus (cremini) to 16.8 g/100 g dry mass in Auricularia auricula-judae (wood ear). The following mushrooms demonstrated the greatest percentage of 1,3-1,6-β-D-glucan contents in relation to the total β-glucan content: Gyroporus cyanescens (54%), Suillus granulatus (49.8%), Auricularia auricula-judae (47.9%), and Suillus variegatus (40.6%).

Conclusions: Among the analyzed species, wild-growing mushrooms had a generally higher average 1,3-1,6-β-Dglucan content compared with cultivated mushrooms such as A. bisporus. The highest average content of these polysaccharides was observed in medicinal mushroom Auricularia auricula-judae. Comparable 1,3-1,6-β-D-glucan content, in relation to this mushroom species, was found in Gyroporus cyanescens, Suillus granulatus and Suillus variegatus, which points to the possibility of the use of these species of mushrooms as medicinal foods.