Analyses were performed using HPLC Shimadzu coupled with RI detector and equipped with Aminex HPX-87H (BIO-RAD column) (300 x 7.8 mm; 9 µm). Conditions: mobile phase was H2SO4 (5 mM) eluted with a flow rate of 0.7 mL.min -1 for 60 min (Isocratic) at 60 °C. Injection volumes of 10 µL were used for all samples.