Official checks by an accredited laboratory on irradiated foods at an Italian market

Food irradiation can be used to increase the microbiological safety and to extend the shelf life of foods. European legislation states that any food or food ingredients must be labelled and every year each Member State, particularly Italy, has to carry out checks at marketing stage. This work reports on the results of analytical controls on 451 foodstuff samples over the period 2006–2011 performed by an Italian accredited laboratory using 4 different screening and confirmatory techniques: PSL, DNA Comet Assay, TL and ESR. A total of 18 samples were found non-compliant: 6 frog legs, 3 clams, 3 cuttlefish, 1 octopus and 1 shrimps from Vietnam; 3 squids, 1 white pepper and 1 chilli tofu from China. Non-compliances are due to both incorrect labelling and irradiation in not approved facilities in extra European/third countries. Check results also showed that among screening methods PSL is the most accurate, simple and practical standard to analyse most of samples (spices, herbs, supplements, mollusks, crustaceans and vegetables) with a low false positive classification (11%) whereas DNA Comet Assay revealed the highest percentage of false positive cases (26%). ESR is the suitable confirmatory method to detect dried fruits and foodstuffs (meat and fish product) containing bone, while TL is the best confirmatory method to detect herbs, spices and supplements, cephalopods, mollusks and crustaceans, besides fresh fruits and vegetables. In conclusion, by comparison with European data, this study suggests more checks on meat products (frog and poultry meats), fish products (cephalopods, mussels and crustacean) spices and supplements especially at import stage from countries where non approved irradiation facilities are operating (e.g. Vietnam and China).