Determination of tocopherol and tocotrienol content of Greek barley varieties under conventional and organic cultivation techniques using validated reverse phase high-performance liquid chromatography method
Article first published online: 6 JAN 2012
Copyright © 2012 Society of Chemical Industry
Journal of the Science of Food and Agriculture
Volume 92, Issue 8, pages 1732–1739, June 2012
How to Cite
Tsochatzis, E. D., Bladenopoulos, K. and Papageorgiou, M. (2012), Determination of tocopherol and tocotrienol content of Greek barley varieties under conventional and organic cultivation techniques using validated reverse phase high-performance liquid chromatography method. J. Sci. Food Agric., 92: 1732–1739. doi: 10.1002/jsfa.5539
- Issue published online: 18 APR 2012
- Article first published online: 6 JAN 2012
- Manuscript Accepted: 31 OCT 2011
- Manuscript Revised: 28 SEP 2011
- Manuscript Received: 22 OCT 2010
BACKGROUND: Tocotrienols and tocopherols (tocols) are important phytochemical compounds with antioxidant activity and potential benefits for human health. Among cereals, barley is a good source of tocols. In the present study the effect of two cultivation methods, organic and conventional, on the tocol content in 12 Greek barley varieties was investigated. A validated reverse phase high-performance liquid chromatography method (RP-HPLC) with fluorescence detection (excitation at 292 nm, emission at 335 nm) was applied along with direct solvent extraction with acetonitrile at a 1:30 (w/v) sample/solvent ratio for tocol quantification.
RESULTS: The results showed statistically significant differences (P < 0.05) between the two cultivation methods (except for δ-tocopherol) as well as among varieties. In the case of organic cultivation the four homologues of tocotrienol (α-, β + γ- and δ-) increased, by 3.05–37.14% for α-tocotrienol, 15.51–41.09% for (β + γ)-tocotrienol and 30.45–196.61% for δ-tocotrienol, while those of tocopherol (α- and β + γ- but not δ-) decreased, by 5.90–36.34% for α-tocopherol and 2.84–46.49% for (β + γ)-tocopherol. A simple correlation analysis between tocols revealed a good correlation between (β + γ)-tocotrienol and δ-tocotrienol. Although there was a significant decrease in the important α-tocopherol in the varieties studied under organic cultivation, there was an overall increase in tocotrienol content.
CONCLUSION: The cultivation method (organic or conventional) had an important effect on tocotrienol and tocopherol concentrations in barley. An overall increase in total tocol content and a clear increment in the tocotrienol/tocopherol ratio were observed. Copyright © 2012 Society of Chemical Industry