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- Exposure assessment of chemicals from packaging materials in foods: reviewPublication . Poças, Maria de Fátima; Hogg, TimIt is recognised that chemicals from packaging and other foodcontact materials can migrate into the food itself and thus be ingested by the consumer. The monitoring of this migration has become an integral part of ensuring food safety. This article reviews the current knowledge on the food safety hazards associated with packaging materials together with the methodologies used in the assessment of consumer exposure to these hazards. Special attention is given to the most promising approaches for exposure assessment and to the technical and other barriers which need addressing.
- Legislação e RegulamentaçãoPublication . Selbourne, Maria do Céu; Poças, Maria de Fátima
- Influência da Embalagem na Qualidade e Preservação do AlimentoPublication . Selbourne, Maria do Céu; Poças, Maria de Fátima
- A quantitative approach to assess the contribution of seals to the permeability of water vapour and oxygen in thermosealed packagesPublication . Reinas, Isabel; Oliveira, Jorge; Pereira, Joel; Mahajan, Pramod; Poças, Maria de FátimaShelf-life of many foods is largely dependent on the barrier to moisture and oxygen of the respective package. Barrier is often assessed by measuring the transmission rate of films. However, in thermosealed packages leaks and weak seals can give rise to increased total mass transfer entering the system and reaching the food. While leaks are random defects and are associated to early failure, lower integrity of regular seals tends to affect whole batch causing a decrease in the product shelf-life. In the present work the contribution of the seals to total permeability of packages was assessed by measuring transmission rate of the film and of thermosealed packages of different sizes, therefore with different seals length. Packages made of PA/PE and PVDC coated PET/PE and their respective films were tested for moisture and oxygen transmission rate at different temperature and relative humidity. Results indicate that industrial regular produced seals can account for ca. 25% of the total mass transfer through the system. This decrease of the package barrier as compared to the material barrier will have a significant impact on the product shelf-life and it should be considered in the packaging design process.
- Materiais em contacto com alimentosPublication . Selbourne, Maria do Céu; Poças, Maria de Fátima
- 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
- A embalagem e o meio ambientePublication . Poças, Maria de Fátima