NATURAL AND GAMMA INDUCED FREE RADICALS IN DRIED FRUITS. AN EPR STUDY

K. Dimov, K. Aleksieva, Tsv.Tsvetkov, I. Nacheva

Abstract: The aim of the present study is to prove radiation processing in air dehydrated dates, prunes and figs, as well as to recommend which part of the fruit to sample. The detection method is Electron Paramagnetic Resonance (EPR) spectroscopy. Before irradiation in date stone, prune stone and flesh, and fig seeds EPR spectroscopy was detected a weak singlet line, whereas date flesh and fig flesh are EPR silent. After gamma-irradiation in date stone and flesh, and fig flesh a “sugar-like” EPR spectrum is recorded. In prune stone a typical “cellulose-like” spectrum is detected, whereas in prune flesh and fig stone only singlet line is recorded as before radiation treatment. Of research done it can be seen that the irradiation is proved in a different part of the fruit. European Protocol EN 13708 is applicable to irradiated dried dates and figs, whereas Protocol EN 1787 for dried prunes.

Keywords: dried fruits; EPR spectroscopy; gamma-irradiation

Date published: 2017-08-31