Transparent thermoreversible gels of β-(1 → 6)-branched β-(1 → 3)-glucan derived from the cauliflower mushroom Sparassis crispa

Sparassis crispa is an edible mushroom and its puree forms a thermoreversible cold-setting gel. In the present study, the gel component was extracted and was analyzed by NMR. The gel component had the same primary structure as reported for the beta-glucan of schizophyllan or scleroglucan, with beta-(1 -> 3)-linked glucose as the main chain and every three residues containing a beta-(1 -> 6)-linked glucose. Large deformation test of this beta-glucan gel at 4 degrees C showed fracture at a strain of approximately 60% in the concentration range from 1.8 to 2.0 wt %. The beta-glucan above a critical molecular weight appears to be required for gel formation.

Automated summary

In this study, the gel component of Sparassis crispa was extracted and analyzed by NMR. The gel component showed the same primary structure as schizophyllan or scleroglucan, with a main chain of beta-(1 -> 3)-linked glucose and every three residues containing a beta-(1 -> 6)-linked glucose. The beta-glucan gel fractured at a strain of approximately 60% in the concentration range of 1.8 to 2.0 wt % at 4 degrees C, indicating that beta-glucan above a critical molecular weight is required for gel formation.