Dietary fibers are defined as hardly digestible components
in foodstuffs which cannot be digested by human digestive
enzymes.!) The dietary fibers include nondigestible organic
materials from plant cell wall components such as cellulose,
lignin, and pectin, as well as chitin, chitosan, and others.
In recent years, several studies on these dietary fibers have
found various activities such as those improving defecation
and reducing the cholesterol level in blood. It has been
revealed that these materials play an important role in
preventing adult diseases. 2