Merck

Fat-soluble bioactive components in colored rice varieties.

Journal of medicinal food (2014-08-28)
Igor Otavio Minatel, Sang-Ik Han, Giancarlo Aldini, Mara Colzani, Nirupa R Matthan, Camila Renata Correa, Denise Fecchio, Kyung-Jin Yeum
ABSTRACT

Bioactive components in rice vary depending on the variety and growing condition. Fat-soluble components such as γ-oryzanol, tocopherols, tocotrienols, carotenoids, and fatty acids were analyzed in brown, sugary brown, red, and black rice varieties using established high-performance liquid chromatography (HPLC) and GC methodologies. In addition, these colored rice varieties were further analyzed using a high-resolution liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS) (LTQ-Orbitrap XL) to identify the [M-H](-) ions of γ-oryzanol, ranging from m/z 573.3949 to 617.4211. The highest content of tocopherols (α-, 1.5; γ-, 0.5 mg/100 g) and carotenoids (lutein 244; trans-β carotene 25 μg/100 g) were observed in black rice; tocotrienols (α-, 0.07; γ-, 0.14 mg/100 g) in red rice, and γ-oryzanol (115 mg/100 g) in sugary brown rice. In all colored rice varieties, the major fatty acids were palmitic (16:0), oleic (18:1n-9), and linoleic (18:2n-6) acids. When the γ-oryzanol components were further analyzed by LC-MS/MS, 3, 10, 8, and 8 triterpene alcohols or sterol ferulates were identified in brown, sugary brown, red, and black rice varieties, respectively. Such structural identification can lead to the elucidation of biological function of each component at the molecular level. Consumption of colored rice rich in beneficial bioactive compounds may be a useful dietary strategy for achieving optimal health.

MATERIALS
Product Number
Brand
Product Description

Supelco
Tetrahydrofuran, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Tetrahydrofuran, ReagentPlus®, ≥99.0%, contains 250 ppm BHT as inhibitor
Sigma-Aldrich
tert-Butyl methyl ether, reagent grade, ≥98%
Sigma-Aldrich
Methanol, ACS spectrophotometric grade, ≥99.9%
Supelco
Methanol, Pharmaceutical Secondary Standard; Certified Reference Material
Supelco
tert-Butyl Methyl Ether, Pharmaceutical Secondary Standard; Certified Reference Material
Sigma-Aldrich
tert-Butyl methyl ether, ACS reagent, ≥99.0%
Sigma-Aldrich
Ammonium acetate, ≥99.99% trace metals basis
Sigma-Aldrich
Methanol, puriss. p.a., ACS reagent, reag. ISO, reag. Ph. Eur., ≥99.8% (GC)
Sigma-Aldrich
Ammonium acetate, ACS reagent, ≥97%
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Tetrahydrofuran, contains 250 ppm BHT as inhibitor, ACS reagent, ≥99.0%
Sigma-Aldrich
Methanol, BioReagent, ≥99.93%
Sigma-Aldrich
tert-Butyl methyl ether, HPLC Plus, for HPLC, GC, and residue analysis, 99.9%
Sigma-Aldrich
Tetrahydrofuran, ACS reagent, ≥99.0%, contains 250 ppm BHT as inhibitor
Sigma-Aldrich
tert-Butyl methyl ether, suitable for HPLC, ≥99.8%
Sigma-Aldrich
Methanol, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Methanol, HPLC Plus, ≥99.9%
Sigma-Aldrich
Methanol, suitable for HPLC, gradient grade, ≥99.9%
Sigma-Aldrich
Tetrahydrofuran, inhibitor-free, suitable for HPLC, ≥99.9%
Sigma-Aldrich
Methanol, suitable for HPLC, gradient grade, suitable as ACS-grade LC reagent, ≥99.9%
Sigma-Aldrich
Methanol, Laboratory Reagent, ≥99.6%
Sigma-Aldrich
Tetrahydrofuran, contains 250 ppm BHT as inhibitor, puriss. p.a., ACS reagent, reag. Ph. Eur., ≥99.9%
Sigma-Aldrich
Methanol, ACS reagent, ≥99.8%
Sigma-Aldrich
Methanol, Absolute - Acetone free
Sigma-Aldrich
tert-Butyl methyl ether, puriss. p.a., ≥99.5% (GC)
Sigma-Aldrich
Methanol, puriss., meets analytical specification of Ph Eur, ≥99.7% (GC)
Sigma-Aldrich
tert-Butyl methyl ether, reagent grade, 98%
Sigma-Aldrich
Ammonium acetate solution, for molecular biology, 7.5 M