Free and bound phenolic profiles and antioxidant activity of milled fractions of different indica rice varieties cultivated in southern China.
This study quantified free and bound phytochemicals and their antioxidant activity in the endosperm and bran/embryo of different indica rice varieties. Phytochemicals mainly existed as free form in the bran/embryo and as both free and bound forms in the endosperm. The average values of total phenolic content, flavonoid content, FRAP, ABTS and ORAC values in the bran/embryo were 3.1, 10.4, 8.2, 11.2 and 11.4 times higher than those in the endosperm, respectively. In whole brown rice, the bran contributed 59.2%, 53.7%, 47.7%, 55.5% and 56.9% of total phenolics, flavonoids, FRAP, ABTS and ORAC values, respectively. Seven individual phenolics (gallic, protocatechuic, chlorogenic, caffeic, syringic, coumaric and ferulic acids) were detected with most coumaric and ferulic acids in the bran. All measurements exhibited varietal differences. These findings provide important information for improving human health by encouraging the consumption of whole brown rice and its use in food product development.
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Huihui
H
Ti
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Qing
Q
Li
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Ruifen
R
Zhang
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China. Electronic address: mwzhh@vip.tom.com.
Mingwei
M
Zhang
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Yuanyuan
Y
Deng
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Zhencheng
Z
Wei
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Jianwei
J
Chi
Sericultural and Agri-Food Research Institute, Guangdong Academy of Agricultural Sciences, Guangzhou 510610, PR China.
Yan
Y
Zhang
D000975:Antioxidants / Q000494:pharmacology*; D002681:China; D003373:Coumaric Acids / Q000032:analysis; D005419:Flavonoids / Q000032:analysis; D006801:Humans; D012275:Oryza / Q000737:chemistry*; D010636:Phenols / Q000032:analysis*; D010936:Plant Extracts / Q000494:pharmacology*
D000975:Antioxidants; D003373:Coumaric Acids; D005419:Flavonoids; D010636:Phenols; D010936:Plant Extracts; C004999:ferulic acid
Antioxidant activity; Flavonoids; Milled rice fraction; Phenolic acids; Phenolics; Rice variety