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Gewählte Master / Diploma Thesis:

Martina Helmlinger (2020): The Suitability of the Microplate-Format Ames Test for Food Contact Material Genotoxicity Assessment.
Master / Diploma Thesis - Institut für Lebensmittelwissenschaften, BOKU-Universität für Bodenkultur, pp 143. UB BOKU obvsg

Data Source: ZID Abstracts
DNA-reactive genotoxins may be present in food contact materials (FCMs) and can leach into foodstuffs, thereby affecting food safety. For these substances, a stringent exposure threshold of 0.0025 µg/kg bodyweight/day applies. Current analytical techniques, however, cannot rule out genotoxic contaminations in FCMs which would lead to exceeding exposures. Therefore, a supportive FCM assessment strategy based on a microplate-format Ames test with a sample pre-concentration step has been proposed. The present study evaluated the suitability of this strategy with a focus on analytical sensitivity and specificity in FCM matrices. To that end, the achievable concentration factor during sample pre-concentration by parallel evaporation was approximated with five model substances. With a recovery of 45%, semi-volatiles could be concentrated by a factor of 135, while volatiles could not be recovered. Further, the analytical sensitivity of the microplate-format Ames test with Salmonella Typhimurium strains TA98 and TA100 was assessed. The lowest effective concentrations (LECs) of eight genotoxins were determined in three FCM matrices and ranged from 6 µg/mL to 2500 µg/mL. Importantly, matrix influences on LECs were found manageable. Complementary, the detectability of additive genotoxic effects in mixtures was demonstrated, and the test specificity was 100%, indicating the utility of the test for complex mixtures. Lastly, ten coating and plastic FCMs were screened and determined as non-mutagenic. To discuss the suitability of the strategy for FCM assessment, required sample-specific LECs were established based on reached concentration factors and intended uses. As achieved LECs exceeded the required LECs by factors of 7 to 6*10^5, the strategy was found unsuitable to detect genotoxins at relevant levels. Although it can thus only serve as non-compliance test, the strategy represents a valuable complement to analytical FCM assessment and is worth pursuing further.

Beurteilende(r): Domig Konrad

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