This paper focused on the production of methane gas to confirm that food waste has the
potential to produce optimum amounts of methane gas. Figure 3 shows the percentages
of methane production for Mixtures 1, 2 and 3. The graph shows that the percentage
of methane gas production was initially low because of the high concentration of
VFAs in the early phase. This high concentration made the conditions unsuitable for
methanogenic bacterial growth. However, after the VFA concentrations decreased,
methanogenic bacteria became very aggressive (Marchaim and Krause, 1993; Fukuzaki
et al., 1990).