2.2.1. Modified starter
The modified starter was purchased from Korea Enzyme Company,
Seoul Korea, which was modified from the Korean traditional
starter by using wheat flour as raw material instead of wheat grain,
and using screened pure microorganisms such as Rhizopus japonicus,
Aspergillus oryzae and Hansenula yeast as inoculum instead of
the microorganisms from environment. The general culture conditions
were the same as those used by So, Lee, and Noh (1999).