title: Extraction of defatted rice bran with subcritical aqueous acetone.
abstract: Defatted rice bran extracts were obtained by subcritical treatment using aqueous acetone as extractant. Treatment with 40% (v/v) acetone at 230 °C for 5 min yielded an extract with the highest 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity (0.274 mmol of ascorbic acid/g of bran), total carbohydrate (0.188 g/g of bran), protein (0.512 g/g of bran), and total phenolic contents (88.2 mg of gallic acid/g of bran). The effect of treatment temperature (70-230 °C) was investigated using 40% (v/v) acetone, and the extract under 230 °C treatment showed the highest levels of all the determinations described above. The extracts obtained with various concentrations of aqueous acetone were subjected to UV absorption spectra and HPLC analysis, and the results showed changes in composition and polarity. Antioxidative activity evaluated against oxidation of bulk linoleic acid of the extract obtained with 80% (v/v) acetone was higher than that not only of the extract from subcritical water treatment but also of that obtained 40% (v/v) acetone treatment.
authors.affiliation: Division of Food Science and Biotechnology, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
authors.forename: Tai-Ying
authors.initials: TY
authors.lastname: Chiou
authors.forename: Tze Loon
authors.initials: TL
authors.lastname: Neoh
authors.forename: Takashi
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Shuji
authors.initials: S
authors.lastname: Adachi
mesh_terms: D000096:Acetone / Q000737:chemistry*; D001205:Ascorbic Acid / Q000737:chemistry; D001713:Biphenyl Compounds / Q000037:antagonists & inhibitors*; D002851:Chromatography, High Pressure Liquid; D005227:Fatty Acids / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry*; D005707:Gallic Acid / Q000737:chemistry; D006358:Hot Temperature; D019787:Linoleic Acid / Q000737:chemistry; D059625:Liquid-Liquid Extraction; D012275:Oryza / Q000737:chemistry*; D010851:Picrates / Q000037:antagonists & inhibitors*; D010936:Plant Extracts / Q000737:chemistry*; D012997:Solvents; D014867:Water
chemical_list: D001713:Biphenyl Compounds; D005227:Fatty Acids; D016166:Free Radical Scavengers; D010851:Picrates; D010936:Plant Extracts; D012997:Solvents; D014867:Water; D000096:Acetone; D005707:Gallic Acid; D019787:Linoleic Acid; C004931:1,1-diphenyl-2-picrylhydrazyl; D001205:Ascorbic Acid