Free radical generation in uncooked carrot (Daucus carota) root tissue after cell disruption – A model for chemical reactions during mastication

Free radical processes resulting from cell disruption of carrot hypocotyl root stock have been investigated at various developmental stages and positions using EPR spectroscopy in combination with chemical spin traps, in order to simulate reactions that might occur in the mastication process when eating raw carrot tissue. With the spin trap PBN, EPR spectra corresponded to a carbon-centred radical adduct of the spin trap and the N-(t-butyl)aminoxyl radical, an oxidative breakdown product of the spin trap. When 4-POBN was used, an oxidation product of the spin trap was observed along with the N-(t-butyl)aminoxyl radical. These oxidation reactions were strongest in the root tips. Additional measurements with spin traps DEPMPO and DPPMPO showed the formation of hydroxyl radical adducts. Thus oxidative free radical production occurs on cell disruption, especially in rapidly developing tissue, a result which suggests that free radicals might not be detrimental components of foods.