Rice antioxidants: phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid
Article first published online: 21 JAN 2014
© 2014 The Authors. Food Science & Nutrition published by Wiley Periodicals, Inc.
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Food Science & Nutrition
Volume 2, Issue 2, pages 75–104, March 2014
How to Cite
Food Science & Nutrition 2014; 2(2): 75–104
- Issue published online: 13 MAR 2014
- Article first published online: 21 JAN 2014
- Manuscript Accepted: 25 NOV 2013
- Manuscript Revised: 18 NOV 2013
- Manuscript Received: 2 OCT 2013
- European Union
- Operational Competitiveness Programme. Grant Number: FCOMP-01-0124-FEDER-022692
- Portuguese Foundation for Science and Technology. Grant Number: PTDC/AGR-AAM/102529/2008
- phenolic compounds;
- phytic acid;
- vitamin E;
Epidemiological studies suggested that the low incidence of certain chronic diseases in rice-consuming regions of the world might be associated with the antioxidant compound contents of rice. The molecules with antioxidant activity contained in rice include phenolic acids, flavonoids, anthocyanins, proanthocyanidins, tocopherols, tocotrienols, γ-oryzanol, and phytic acid. This review provides information on the contents of these compounds in rice using a food composition database built from compiling data from 316 papers. The database provides access to information that would have otherwise remained hidden in the literature. For example, among the four types of rice ranked by color, black rice varieties emerged as those exhibiting the highest antioxidant activities, followed by purple, red, and brown rice varieties. Furthermore, insoluble compounds appear to constitute the major fraction of phenolic acids and proanthocyanidins in rice, but not of flavonoids and anthocyanins. It is clear that to maximize the intake of antioxidant compounds, rice should be preferentially consumed in the form of bran or as whole grain. With respect to breeding, japonica rice varieties were found to be richer in antioxidant compounds compared with indica rice varieties. Overall, rice grain fractions appear to be rich sources of antioxidant compounds. However, on a whole grain basis and with the exception of γ-oryzanol and anthocyanins, the contents of antioxidants in other cereals appear to be higher than those in rice.