This study aimed to verify the applicability of the EN 1787 method for the detection of irradiation in herbal ingredients used in Plant Food Supplements (PFSs). In matrices such as herbs and spices the main limit of the method is the presence of intrinsic radicals responsible for spurious signals leading to complex ESR spectra. To overcome this limit, before ESR measurement a treatment with alcohol has been proposed (Delincee and Soika, 2002; Ahn et al., 2012, 2014). As reported in the literature, this treatment is expected to reduce/eliminate the confounding signals so that the samples may be correctly classified. In this study the efficacy of the pre-treatment was tested on raw herbal ingredients largely used for PFSs, namely Camellia sinensis, Cinnamomum verum, Curcuma longa, Ginkgo biloba, Silybum marianum, Vaccinium myrtillus and Zingiber officinale. Non-irradiated and irradiated (5, 10 kGy) samples were analysed before and after pre-treatment. The results showed a general decrement of signal intensity. In some cases, this was associated with the elimination of some spurious signals, which, however, did not always ensue in an easier interpretation of the ESR spectra. Only for two matrices (Camellia sinensis and Vaccinium myrtillus) was alcoholic extraction crucial for the correct classification of the samples.
This paper presents the successful application of total reflection X-ray fluorescence spectroscopy (TXRF) for the identification of products obtained from mechanically separated meat (MSM), a very important issue for food quality and safety. According to the European Food Safety Authority, one of the most important parameters to distinguish MSM is the content of Ca. Consequently, the development of reliable and cost-effective analytical tools is very important to monitor the chemical composition of these foods. In this study, we have developed an analytical method for elemental analysis of meat samples based on total reflection X-ray fluorescence. A simple sample preparation by suspending the grinded meat sample in a solution of diluted Triton X-100 and polyvinyl alcohol in water showed to be the best for this kind of samples. Fresh chicken meat, chicken meat with different percentage of MSM, pure MSM and meat products prepared with MSM were analyzed. The content of K, Ca, Fe, Cu and Zn was determined. Results show that Ca, but also K and Fe are significant markers to distinguish MSM from fresh meat. A limit of 40% MSM for differentiation was achieved by applying principal component analysis. The method accuracy was evaluated comparing the obtained results with those obtained after acidic digestion and ICP-MS analysis.