β-Glucan was solubilised in concentrated hydrochloric acid (HCl) (37%, 10 N) and then extensively hydrolysed by 1.3 N HCl at 100 °C for 2 h. After that, 10 ml of 2 N KOH were added to the suspensions of samples and then the whole was transferred to a 100 ml volumetric flask, using 200 mM sodium acetate buffer (pH 5)