Edible flowers of Viola tricolor L. as a new functional food: Antioxidant activity, individual phenolics and effects of gamma and electron-beam irradiation
Edible flowers are used in food preparations, being also recognized for their beneficial effects on human health. Nevertheless, these species are highly perishable, and irradiation treatment might be applied to ensure food quality and increase their shelf life. Viola tricolor L. is a typical edible flower, with multiple applications and biological properties, mainly provided by the flavonoid content. In the present work, the phenolic compounds were analyzed by HPLC-DAD-ESI/MS, and the antioxidant activity was evaluated using biochemical assays. Linear discriminant analyses (LDA) were performed in order to compare the results obtained with flowers submitted to different irradiation doses and technologies (cobalt-60 and electron-beam). In general, irradiated samples (mostly with 1 kGy) showed the highest phenolic content and antioxidant activity. Furthermore, the significant differences observed in the LDA allow determination of which dose and/or technology is suitable to obtain flowers with higher antioxidant potential.
The authors are grateful to the Fundação para a Ciência e a Tecnologia (FCT, Portugal) for financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2011), João C.M. Barreira (SFRH/BPD/72802/2010 grant) and L. Barros (“Compromisso para a Ciência 2008” contract). The GIP-USAL is financially supported by the Spanish Government through the Consolider-Ingenio 2010 Programme (FUN-C-FOOD, CSD2007-00063). To CNEN, CAPES, CNPq and IPEN-CNEN/SP for financial support to Amanda Koike. This research is included in a Bilateral action FCT-CNPq, Portugal/Brazil 2014.
