Characteristics and antioxidative ability of defatted rice bran extracts obtained using several extractants under subcritical conditions.
Defatted rice bran was treated with water, 50% (v/v) ethanol, ethanol, 50% (v/v) acetone, or acetone. The treatment temperature and time were fixed at 230°C and 5 min, respectively. The treatment with 50% (v/v) acetone produced the highest yield of 0.549 g-extract/g-bran, and the extract exhibited the highest DPPH radical scavenging activity of 0.495 mmol-ascorbic acid/g-extract. The extract obtained with 50% (v/v) acetone showed the higher UV absorbance and highest amount of hydrophobic substances in the HPLC analysis than the other extracts, and it also showed the highest antioxidative ability in both the rancidity test at 105°C and bulk oil system at 60°C for the longest induction period of 4.9 h and 14.4 h, respectively. However, the extracts obtained using various extractants showed no effect on the oxidation rate constant of linoleic acid in the bulk oil system.
Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto, Japan.
Tai-Ying
TY
Chiou
Akane
A
Ogino
Takashi
T
Kobayashi
Shuji
S
Adachi
D000096:Acetone; D000975:Antioxidants / Q000494:pharmacology*; D001713:Biphenyl Compounds; D002851:Chromatography, High Pressure Liquid; D000431:Ethanol; D016166:Free Radical Scavengers; D019787:Linoleic Acid; D012275:Oryza / Q000737:chemistry*; D010851:Picrates; D010936:Plant Extracts / Q000494:pharmacology*; D012997:Solvents; D013696:Temperature; D013997:Time Factors; D014867:Water
D000975:Antioxidants; D001713:Biphenyl Compounds; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D000096:Acetone; D000431:Ethanol; D019787:Linoleic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl