publications

Article

Salt effect on phenolics and antioxidant activities of Tunisian and Canadian sweet marjoram (Origanum majorana L.) shoots

BAATOUR Olfa, MAHMOUDI Hela, TARCHOUNE Imen, NASRI Nawel, TRABELSI Najla, KADDOUR Rym, ZAGHDOUDI Maha, HAMDAOUI Ghaith, KSOURI Riadh, LACHAAL Mokhtar, MARZOUK Brahim, 2012

Journal of the Science of Food and Agriculture, 93, 1, 134-141, Juin 2012

Résumé

The results showed a significant variability in phenolic composition and antioxidant behavior between the two varieties under salt stress. The phenolic composition of methanolic extracts was determined by reversed-phase high-performance liquid chromatography. Amentoflavone was the predominant flavonoid compound; in addition, trans-2-hydrocinnamic acid became the major phenolic acid with salt treatment of the Tunisian variety. In the control, Canadian variety extract was characterized by high levels of gallic acid and amentoflavone. However, under 75 mmol L(-1) NaCl, gallic acid content doubled, whereas amentoflavone content was maintained in the Canadian variety. Stimulation of phenolic acid biosynthesis was observed in these two varieties under salt treatment despite the fact that shoots of the Tunisian variety showed higher antioxidant activities compared to those from the Canadian variety. Tunisian O. majorana might have developed tolerance to salinity and avoided tissue damage by activating enzymes involved in the galactosylation of quercetin into quercetin-3-galactoside and quercetin-3-rhamnoside.