γ‐Oryzanols of North American Wild Rice (Zizania palustris)

Abstract

γ-Oryzanol, a natural mixture of ferulic acid esters of triterpene alcohols and sterols, are an important bioactive components present in rice bran oil. In light of the recent increase in the popularity of wild rice among consumers, and the possibility of a direct relationship between γ-oryzanol composition and its bioactivity, the oryzanol profile of major wild rice (Zizania palustris) grown in North America was studied and compared to regular brown rice (Oryza sativa L.). A total of twenty-three γ-oryzanol components were separated, identified and quantified by HPLC coupled to an Orbitrap MS. The distribution of individual γ-oryzanols was similar for all the wild rice but significantly different from those of the regular brown rice. Unlike in the regular brown rice, a significant amount of steryl caffeate and cinnamate were found in the wild rice samples. Generally, the amounts of γ-oryzanol in the wild rice were higher compared to the regular brown rice, 1,352 vs. 688 μg/g. The results from this study showed that wild rice had a more diverse γ-oryzanol composition and the higher amounts compared to the regular brown rice.

Differentiation of rice varieties using small bioactive lipids as markers

“…In our study, sitosteryl ferulate (marker 125) is also a CM for wild rice, which is observed as having a higher intensity in wild rice coming from Canada than originating from USA. In the literature, profiles of individual steryl ferulates including sitosteryl ferulate in wild rice have been reported to be location dependent . The approach applied in this study can also distinguish different types of wild rice from different origins mainly based on compounds other than steryl ferulates.…”

Brown Rice Versus White Rice: Nutritional Quality, Potential Health Benefits, Development of Food Products, and Preservation Technologies

“…The composition of individual γ‐oryzanols was similar among the wild rice samples but significantly different from those of the regular BR. In addition, the amount of γ‐oryzanol in wild rice was greater than those of regular BR (Aladedunye, Przybylski, Rudzinska, & Klensporf‐Pawlik, ). In another study, BR was found to contain 1.5 mg/g GABA and 0.38 mg/g γ‐oryzanol.…”

Spatial distribution mapping of molecules in the grains of different rice landraces, using desorption electrospray ionization mass spectrometry

“…In Figure , gluconic acid, a glucose oxidation product ( m/z 195.0), is seen to be localized in the embryo of G02, G38, H24, H34, K11 and T05 rice varieties. The multiple components of γ ‐oryzanol are made up of the esters of triterpene alcohol ferulates and sterol ferulates . Two of the major γ ‐oryzanol components of the rice bran oil such as cycloartenyl ferulate (oryzanol A, m/z 601.5) and 24‐methyl cycloartenyl ferulate (oryzanol C, m/z 615.5) were mapped along the bran region of the rice varieties.…”

“…The multiple components of γ-oryzanol are made up of the esters of triterpene alcohol ferulates and sterol ferulates. 26,27 Two of the major γ-oryzanol components of the rice bran oil such as cycloartenyl ferulate (oryzanol A, m/z 601.5) and 24-methyl cycloartenyl ferulate (oryzanol C, m/z 615.5) were mapped along the bran region of the rice varieties. Oryzanol distribution is more pronounced in the T05 rice variety than the other rice landraces.…”