Effects of microfluidization with ionic liquids on the solubilization and structure of β-d-glucan

In order to enhance the solubility of yeast β- d -glucan and enlarge the applicable area, we investigated dynamic high pressure microfluidization (DHPM) treatment with ionic liquids as solvent to prepare water-soluble yeast β- d -glucan (WSG). The solubility of β- d -glucan was greatly impacted by the pressure of DHPM, residence time, and ratio of β- d -glucan and EmimAc. The yield of WSG reached 79.25 % (w/w) with the water solubility of 72.50 % (w/w). The DHPM treatment did not destroy the ionic liquid structure therefore the ionic liquids could be recycled. FTIR and 13C NMR spectrum results showed that WSG was the polysaccharides with (1 → 3)-β- d -glycosidic bonds, after modification, the hydrogen bonding was destroyed. The chain conformation of WSG in 0.1 M NaNO3 aqueous solutions at 25 °C were studied by laser light scattering and viscometry. The Mark-Houwink equation was established to be [η] = 2.09 × 10−2MW0.63 (cm3 g−1). According to the conformational parameters calculated from wormlike cylinder model, WSG existed as semi-stiff chain in aqueous solution.