Sprouting and elicitation with natural elicitors as an effective tools for improving antioxidant activity of potentially bioaccessible wheat phytochemicals

Antioxidant activity of potentially bioaccessible phytochemicals from 4-days-old sprouts of Polish winter wheat (Triticum aestivum ssp. vulgare) cultivars: Bogatka, Mulan and Muszelka were studied. Before germination seeds were treated with three kinds of natural elicitors: 0.1% (w/v) of Saccacharomyces cerevisiae (SC) extract, 0.1% (w/v) Salix daphnoides (SD) bark extract and their combinations (1:1, SCD) and distilled water (control) (6h, 25 °C) and were germinated at 20 °C in darkness. Potentially bioaccessible phytochemicals were released during digestion in the simulated human gastrointestinal tract. Antiradical activity (ABTS radical cation decolorization; AA), ferric reducing power (FRAP), Fe(II) ions chelating ability (CHEL) and ability to prevent linoleic acid against oxidation (LPO) were estimated. The analysis of variance (ANOVA) and Tukey's post-hoc test were used to compare groups (α= 0.05). Sprouting significantly decreased AA activity of potentially bioaccessible phytochemicals from Mulan and Bogatka, whereas such impact on Muszelka sprouts was not observed. Elicitation with all elicitors significantly increased AA activity of Bogatka sprouts, whereas in the case of Muszelka and Mulan such impact was observed after treatment with SD and SCD. Sprouting significantly increased RP and CHEL in respect of wheat variety. Treatment not influenced on RP of Bogatka sprouts. Sprouting and treatments with all elicitors significantly increased LPO activity of potentially bioaccessible compounds from Bogatka and Muszelka sprouts. Elicitation significant increased LPO. Treatments with all elicitors increased CHEL activity of potentially bioaccessible compounds from Bogatka and Muszelka seeds, whereas in the case of Mulan SCD was not effective. Especially high effect of SD was obtained for antiradical activity, chelating power and ability to lipid prevention.

Acknowledgement: The study was financed by the Polish National Science Centre (Grant 2012/07/B/NZ9/02463).