2.5.4.1. Sugar analysis. Sugar analysis (glucose, fructose and sucrose) was performed by HPLC with amobile phase of acetonitrile (ACN) and water (80:20 v/v). Several ratios were initially trialed including 75:25, 70:30, and 88:12 v/v. The mobile phase was vacuum filtered through 0.2m membrane before using at a flow rate of 1.5 mL/min with 10L sample injection volume.