Radiation chemistry of solid-state carbohydrates using EMR

We review our research of the past decade towards identification of radiation-induced radicals in solid state sugars and sugar phosphates. Detailed models of the radical structures are obtained by combining EPR and ENDOR experiments with DFT calculations of g and proton HF tensors, with agreement in their anisotropy serving as most important criterion. Symmetry-related and Schonland ambiguities, which may hamper such identification, are reviewed. Thermally induced transformations of initial radiation damage into more stable radicals can also be monitored in the EPR (and ENDOR) experiments and in principle provide information on stable radical formation mechanisms. Thermal annealing experi-ments reveal, however, that radical recombination and/or diamagnetic radiation damage is also quite important. Analysis strategies are illustrated with research on sucrose. Results on dipotassium glucose-1-phosphate and trehalose dihydrate, fructose and sorbose are also briefly discussed. Our study demonstrates that radiation damage is strongly regio-selective and that certain general principles govern the stable radical formation

A study of stable isotope composition of chosen foodstuffs from the Polish market

In the present work the carbon and nitrogen isotopic composition of food products bought in the retail trade in Warsaw is demonstrated. The research was carried out using meat (pork, chicken), hen eggs and honey. These products originated from the conventional and ecological farms. The values of the isotopic ratios are expressed as δ notation and correspond to the international standards (V-PDB for δ13C, and air for δ15N) according to the following general formula: δ(‰) = [(R sample / R standard) – 1] × 1000, where R represents the ratio between the less abundant and more abundant isotopes, in particular 13C/12C and 15N/14N. The results received in our laboratory, were compared with results presented in the literature for similar products. The results of the study show that the N and C stable isotope ratios in the tested products can be applied to verify their authenticity

Detection of irradiated components in flavour blends composed of non-irradiated spices, herbs and vegetable seasonings by thermoluminescence method

The results of experiments on the detection of irradiated component in commercial flavour blends composed of a mixture of non-irradiated spices, herbs and seasonings are presented. A method based on the thermoluminescence measurements on silicate minerals isolated from blends has been adapted. It has been proved that by applying this technique it is possible to detect 0.05% by weight of paprika, irradiated earlier with a dose of 7 kGy, which was a minor component of nonirradiated flavour blends

Detection of radiation treatment of dry plant extracts by thermoluminescence and pulsed photostimulated luminescence. Comparative study

Results of the examination of the variety of dry plant extracts (Thyme extract, Celery seed extract, Artichoke extract, Citrus aurantium extract and others) by two different detection methods are described. Both PSL and TL methods are presented and discussed. Comparative study based on the analysis of the results obtained by thermoluminescence (TL) and photostimulated luminescence (PSL) measurements delivered the arguments that preselection of detection methods based on model studies is rational to be adapted in analytical laboratories specialized in the detection of irradiated foods