The profiles of bioactive compounds (including phenolics and flavonoids in free and bound
fractions, anthocyanins, proanthocyanidins, vitamin E, and g-oryzanol) of outer and inner
rice bran from six colored rice samples collected from local markets were investigated.
Proanthocyanidins could only be detected in red rice bran but not in black rice bran. The
free fraction of the extracts dominated the total phenolics (72e92%) and the total flavonoids
(72e96%) of colored rice bran. Most of the phenolic acids (83e97%) in colored rice
bran were present in the bound form. Protocatechualdehyde was identified for the first
time in the bound fraction of red rice bran by high performance liquid chromatographyphotodiode
array/electrospray ionization tandem mass spectrometry. The antioxidative
activities of the free fraction of the colored rice bran were attributed to the proanthocyanidins
in red colored rice and anthocyanins in black rice, while that of the bound fraction
was mainly due to the phenolic acids.
Copyright © 2016, Food and Drug Administration, Taiwan. Published by Elsevier Taiwan
LLC. This is an open access article under the CC BY-NC-ND license