> Korean Fermented Foods >Stories of Microorganisms
>Cheonggukjang and Microorganisms
Cheonggukjang known as one of the typical health foods
has its nutritional value from the ingredient of soybeans,
and what makes it a healthier food are the substances additionally
produced by microorganisms.
During the fermentation of Cheonggukjang, sticky substance
(polyglutamate) having anti-cancer effects and the nucleic
acid (polymer) with immune-enhancement effects, the antioxidant
of browning substances, and the protease having thrombolytic
effects are produced. This is done by bacilli, and these
microorganisms degrade the protein in soybeans and change
them into smaller pieces of amino acids that they can increase
the absorptivity of soybeans in Cheonggukjang into the human
body, and they also weaken the intestinal saprogenic bacteria
and fight against the disease germs. These bacteria beneficial
for human body suppress the action of saprogenic bacteria
to reduce the carcinogen or cancer-causing agents like ammonia,
indole, or amine. In addition, they can adsorb to these
harmful substances and discharge them. Most of the harmful
substances can be detoxicated in a liver, but if they are
decreased by the functions of Cheonggukjang, the burden
of a liver can be lightened that it can do more for recovering
fatigue or preventing the roughness of skin. In particular,
it has plenty of vitamin B2, so it can protect the liver
suffered from drinking or smoking by improving its detoxicating
functions. Beans contain much of the vitamin B2, 0.3mg per
100g, but it is sharply decreased when boiled. However,
when the boiled beans become Cheonggukjang through fermentation,
the amount of vitamin B2 gets increased to 0.56mg which
is even more than that of raw beans.
Bacilli can also stimulate internal organs to activate the
digestion by producing organic acid.
Various kinds of bacteria act in Cheonggukjang. The Cheonggukjang’s
taste and flavor depend on the strain that ferments the
soybeans. Therefore, it is important which strain is used
in it, and the bacteria’s shape, color, and characteristics
differ from each other by strain. These various kinds of
bacteria change the Cheonggukjang’s taste and savor.
In general, the traditional Cheonggukjang is made by the
process that the beans soaked in water and boiled are mixed
with rice straw to make them fermented by the strain that
moves to the beans from the straw. In the temperature of
37~42℃ and the humidity of 80%, as the beans are fermented
for two or three days, the brown color gets thicker and
sticky white thread is created, and when the thread is more,
the quality of Cheonggukjang gets higher.