Analytical methods
Glucose, DP4+ (high saccharides containing four or more glucose), lactic
acid, and ethanol concentrations were determined by HPLC (Agilent 1200).
The HPLC method is based on a normal chromatography procedure, using a
Phenomenex Rezex Cal organic acid column (California, USA), the size of
which is 300x7.8 mm, and a refractive index detector. Eluent was 5 mM
H2SO4 flowing at 0.6 ml/min. The volume
of injection for both standard solutions and sample extracts was 20 µl.