Showing papers by "Ramón Catalá published in 2001"

Characterizing the migration of antioxidants from polypropylene into fatty food simulants

Abstract: The migration (diffusion and equilibrium) processes of antioxidants (AOs) from polypropylene (PP) films of different thicknesses into n-heptane and 95% ethanol as fatty food simulants were analysed at 20, 37 and 60°C. Heptane fully extracted the AOs from the polymer while a partition equilibrium described the migration to ethanol. The kinetics of migration were also studied via the diffusion coefficients. As expected, diffusion was found to be faster when the polymer was in contact with heptane, due to polymer swelling by the solvent. The kinetics of the process in ethanol was described by different theoretical expressions which are discussed. Equations disregarding partition equilibrium failed to describe the process and the diffusion coefficient values obtained through them were much smaller than the actual ones and dependent on film thickness. The results also showed the significance of food simulant selection in the analysis of food-packaging interactions and migration variability with thickness.

Food aroma partition between packaging materials and fatty food simulants

Abstract: By means of thermal desorption experiments, the partition equilibrium (partition coefficient, K) was analysed for six food aroma components (d-limonene, n-decane, ethyl caproate, phenylethanol, n-hexanol and hexanal) between three sealable polymer films suitable for direct food contact (ultra-low density polyethylene, ULDPE; ionomer, ION; and polyester, PET) and four fatty food simulants (ethanol 95%, EtOH; sunflower oil, Oil; n-heptane, HEP; and iso-octane, OCT). The results showed that aroma scalping is highly dependent on the fatty food simulant utilized. Polar aroma components were more sorbed into polymers in the presence of a non-polar fatty food simulant, and vice versa. K values in the presence of Oil were always between those in EtOH and in HEP or OCT. In general, PET was the packaging film which showed the lowest partition coefficient for non-polar components while ULDPE showed the lowest partition for polar aromas. The partition equilibrium of mixed d-limonene, ethyl caproate, and n-hexanol was...

Nuevos envases. De la protección pasiva a la defensa activa de los alimentos envasados

Abstract: Los alimentos se deterioran con el tiempo, fundamentalmente por la accion de organismos vivos (mohos, bacterias, insectos, roedores, etc.), la accion fisico-quimica del entorno (temperatura, humedad relativa, oxigeno, radiaciones, etc.) y la actividad biologica del propio alimento. Las medidas tecnologicas adoptadas para evitar o minimizar los efectos adversos de los factores citados han sido la genesis de las tecnicas de conservacion de alimentos. Todas ellas incluyen un amplio conjunto de operaciones de muy distinta naturaleza y complejidad, entre las que se incluye el envasado. Para algunos alimentos el envase constituye unicamente una forma de presentacion o un medio de distribucion comercial, tal sucede con alimentos frescos destinados al consumo inmediato o aquellos que por sus caracteristicas fisico-quimicas pueden considerarse como autoestables. Ahora bien, en general, los alimentos requieren para su comercializacion un estricto control de las condiciones en que se procesan, distribuyen y almacenan. Los envases, interponiendose entre el alimento y el entorno, tienen como mision fundamental reducir la incidencia de los factores externos, protegiendo la integridad del producto y evitando o retrasando la perdida o deterioro de las caracteristicas nutritivas, sensoriales y sanitarias que definen su calidad y aceptacion para el consumo. El envase se configura asi como un elemento fundamental del sistema de conservacion de los alimentos. En general, cualquiera que sea la forma de proteccion a aplicar, el envase es siempre