Soaking Conditions Affect the Contents of Tocopherols, Tocotrienols, and γ-Oryzanol in Pigmented and Non-Pigmented Brown Rice
Journal
JAOCS, Journal of the American Oil Chemists' Society
Journal Volume
92
Journal Volume
92
Journal Issue
11-12
Journal Issue
11-12
Pages
1681-1688
Start Page
1681
End Page
1688
ISSN
0003021X
Date Issued
2015-12-01
Author(s)
Abstract
Tocopherols (Toc), tocotrienols (T3), and γ-oryzanol (GO), important lipid antioxidants in rice, are known to possess various pharmacological properties. In this study, our aim was to examine the effects of soaking conditions on the extractable contents of Toc, T3, and GO in cooked pigmented (PBR) and non-pigmented brown rice (non-PBR). The results showed that Toc, T3, and GO concentrations in non-PBR peaked after soaking at 25 °C for 120 min, whereas soaking conditions showed minimal effects on these compounds in PBR. In non-PBR, high Toc, T3, and GO levels were also noted in the treatments at higher soaking temperatures (45 and 55 °C) with a shorter soaking time (less than 60 min). The GO level in both cultivars was at least ten times greater than the total Vitamin E content. Vitamin E analogues having concentrations greater than 10 mg/kg in PBR and non-PBR were γ-Toc and γ-T3, and α-Toc and γ-T3, respectively. This study concludes that presoaking and cooking processes can improve the extractable contents of Toc, T3, and GO in cooked PBR and non-PBR, and the extraction yield of these bioactive compounds was significantly different between cultivars.
Subjects
Bioactive compounds
Brown rice
Cooking
Oryza sativa
Soaking
Publisher
Springer Verlag
Type
journal article