UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS

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Conference: Bucharest University Faculty of Physics 2012 Meeting


Section: Atomic and Molecular Physics; Astrophysics


Title:
New applications of EPR spectroscopy in food science and cultural heritage


Authors:
V.BERCU (1), C.D.NEGUT (2), O.G.DULIU (1)


Affiliation:
(1) University of Bucharest,Faculty of Physics, Department of Structure of the Matter, Earth and Atmospheric Physics, Astrophysics, P.O. Box MG-11, 077125 Magurele (Ilfov),Romania.

(2) Horia Hulubei, National Institute for Physics and Nuclear Engineering,P.O. Box MG-6, 077125 Magurele (Ilfov), Romania.


E-mail
vasile.bercu@fizica.unibuc.ro


Keywords:
EPR spectroscopy, food science, cultural heritage


Abstract:
Gamma ray irradiation is wily used in food sterilization and cultural heritage for destroying micro-flora and insects involved in bio-deterioration of art works such as paintings. Although, at present time, there are more physical methods able to identify irradiated foods, Electron Paramagnetic Resonance (EPR), Thermoluminescence (TL) and Chemiluminescence (CL) are already accepted by European Committee for Standardization (CEN) as European standards. Among them, EPR seems to be the most adequate in the case of foodstuff containing a hard skeleton. The results concerning X as well as Q band EPR spectra of 60Co gamma ray irradiated edible mushrooms and frog legs are presented and discussed. The sterilization procedure for cultural heritage could alter optical and mechanical properties of paintings. As pigments used in painting retain their crystal structure after mixing with binders, color centers, whose presence results in a more or less persistent color changes, represent the main irradiation defects. Historical pigments usually contain impurities specific to raw materials as well as to preparation methods. Therefore, our study was focused on historical white pigments, the most susceptible to suffer color changes by accumulating color centers. Note: This work was supported by the strategic grant POSDRU/89/1.5/S/58852, Project "Postdoctoral programme for training scientific researchers" co-financed by the European Social Fund within the Sectorial Operational Program for Human Resources Development 2007 – 2013.