1Department
of Pathobiology, Faculty of Science, Mahidol University,
Bangkok 10400, 2Faculty of Agricultural
Technology, Burapha University Sakaeo Campus, Sakaeo
27160, Thailand.
For correspondence:
E-mail: parasit109@yahoo.com
or
scpsw@mahidol.ac.th Tel:
+66-2-201-5550; Fax: +66-2-354-7158
Received: 14 February
2011 Revised
accepted: 30 June 2011
Purpose:
To investigate phenolic levels, phytophenolic profiles
and total antioxidant activities of
Oryza sativa,
unpolished Thai rice.
Methods:
Unpolished Thai rice strains of Leum Phua, Klam, Hawm
Nil and Black Rose were measured for antioxidant
activity using 1,1-diphenyl-2-picrylhydrazyl (DPPH),
2,2’-azinobis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS)
and ferric reducing antioxidant power (FRAP) methods.
Phytophenolic chromatograms were obtained by a high
performance liquid chromatography (HPLC) technique.
Additionally, phenolic content and anthocyanin pigment
were also assayed.
Results:
Oryza
sativa, unpolished
Thai rice strain of Leum Phua showed the highest
antioxidant activity. It was also highest in
anthocyanin pigment. The strains of Leum Phua, Klam,
Hawm Nil and Black Rose showed high levels of phenolic
content: 1.36±0.03, 0.78±0.02, 0.61±0.01 and 0.57±0.02
mg gallic acid/ g sample, respectively. Interestingly,
phytophenolic chromatogram and anthocyanin pigment
levels showed a strong correlation.
Conclusion:
Oryza
sativa, unpolished
Thai rice strain of Leum Phua, has high levels of
anthocyanin pigment, phenolic content and antioxidant
activity. Its pure phytochemical contents should be
further studied for their pharmaceutical benefits.
Keywords:
Antioxidant,
Oryza sativa,
Phenolics, Anthocyanin, Phytochemicals, Thai rice
