The free sugar and organic acid were measured using method of Kim et
al. (13) with modification.
To measure these values, samples were diluted with 5-10oBx, filtrated with a 0.45-μm
membrane filter.
Analysis was conducted via HPLC .
For free sugar analysis, an Econosphere amino column with acetonitrile
at 0.6 mL/min and an refraction index detector were used.
The organic acid analysis used a Rezex ROA-organic acid H+Column with 0.005 N H2SO4 at 0.5 mL/min, measured with a UV detector at 210 nm