Metabolite Changes during Doenjang Fermentation
Results from the 1H NMR analysis of metabolite content
throughout doenjang fermentation are presented in Figure 4.
Glucose, fructose, galactose,and glycerol were identified as the
primary free organic compounds, and their levels increased
quickly during the early fermentation period (Figure 4A).
However, after approximately16 days, glucose and fructose
concentrations dropped by 108 days; they were almost entirely
consumed. In contrast, galactose concentrations continued to
increase until 108 days of fermentation, but then began to
decrease from 179 days, finally approaching zero at 249 days.
Glycerol concentrations reached maximum at 48 days and then
experienced a gradual decrease until the end of fermentation.