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- Migration of two antioxidants from packaging into a solid food and into TenaxPublication . Reinas, I.; Oliveira, J.; Pereira, J.; Machado, P.; Poças, M. F.The migration of chemicals from packaging materials into foods is an important issue in food safety and quality. European legislation sets specific migration limits which compliance must be assessed, surveyed and controlled by industry and authorities. Recently, the new Regulation UE 10/2011 included a new simulant - the Modified Polyphenylene Oxide (Tenax ) for solid dry foods. The objective of this work was to compare the migration kinetics of two antioxidants into Tenax as compared to rice at 3 temperatures: 23, 40 and 70 C. The application of two different solutions of the 2nd Fick’s law to describe and simulate the migration of the migrants to the present systems was studied. Diffusion coefficients ranged between 4.80E-13 and 2.84E-11 cm2/s for the migration into Tenax and between 6.90E-18 and 4.33E-17 cm2/s for the migration into rice. The partition coefficients ranged between 6 and 29 for Tenax and were over 1000 for rice. The activation energy for the migration into rice was half of that for Tenax . The models described relatively well the experimental data (ε < 12% and < 30% for rice and Tenax , respectively). Results indicate that the food simulant tends to overestimate migration values and thus can be safely used to assess materials compliance when materials are intended to contact with rice. However, results also indicate that Tenax is a much more severe simulant in representing rice.
- Consumer exposure to phthalates from paper packaging: an integrated approachPublication . Poças, M.F.; Oliveira, J.C.; Pereira, J.R; Hogg, T.This paper presents an integrated approach to estimate the exposure of the Portuguese population to phthalates as a contaminant originating from paperboard packaging. The approach combined data of migrant concentration in the foods resulting from a stochastic simulation with consumption data of food packaged in paperboard. The results from the exposure model were validated with experimental values actually found in the food. A short surveillance exercise was conducted with samples collection from market shelves to identify and quantify the phthalates present in both the packages and the food. The distribution of values for the di-butyl phthalate concentration in the packages was used as the input of the initial concentration in the Weibull model to estimate the concentration of this phthalate in the foods. This distribution of occurrence data was then combined with the packaging usage data in a probabilistic simulation with a Monte Carlo sampling method. Exposure values ranged between zero and 8.95 mg day 1 kgbw, a value close to the tolerable daily intake established by the European Food Safety Authority (EFSA) – 10 mg day 1 kgbw. However, the 97.5th percentile and the average were 1.82 and 0.44 day 1 kgbw, respectively, indicating that further refinement of the estimates is not necessary. Other phthalates were also detected in the packaging samples: di-isobutyl phthalate and di-ethylhexyl phthalate. The latter was present in all packaging samples collected and was detected in a few food samples at values requiring further investigation.
- Modelling migration from paper into a food simulantPublication . Poças, Maria de Fátima; Oliveira, Jorge C.; Pereira, Joel R.; Brandsch, Rainer; Hogg, TimThe migration of components from paper into Tenax (R) was studied to determine the influence of molecular size and chemical character of the migrant and the influence of paper characteristics in the migration process The Weibull model was applied because Fick s 2nd law of diffusion gave poor fits in some cases The migration pattern depended on the migrants molecular size and was independent of temperature in the studied range The migration rate decreased with the migrant molecular size The influence of the migrants character (polarity and vapour pressure) on the migration behaviour was also studied nonpolar migrants with high vapour pressure presented low relative migration values and polar migrants presented high values of relative migration Results indicated that the apparent partition coefficient between paper and the simulant Tenax (R) increased with the migrant vapour pressure and with both the paper grammage and the recycled pulp content