Bolsas monodosis de almidón con extracto activo y microfibras celulósicas de paja de arroz para la conservación de aceite de girasol

[EN]The ability of different starch-based biodegradable materials to prevent sunflower oil oxidation by pacaking in single-dose bags has been studied. The materials were obtained with corn starch and glycerol as plasticiser (30 % by weight of starch), with an antioxidant extract (0, 4, 6 and 8 % by weight of starch), and with cellulosic fibres (0 and 3 % by weight of starch), both obtained from rice straw. The water vapour and oxygen barrier and optical properties (colour and UV-VIS transmittance) of the materials have been characterized. Water vapour and oxygen barrier capacity improved with the incorporation of the fibres, with and without active extract. On the contrary, when incorporating the extract, oxygen permeability of the films was reduced, but water vapour permeability increased. The films with extract exhibited high UV light absorption capacity and colouring. Single-dose bags were manufactured with the films with 0 and 8 % extract and with and without fibres, which were used for the packaging of sunflower oil. The study of oxidative stability of the latter was performed by an accelerated test with UV light at 30 °C. The peroxides index and TBARS index were analysed in terms of storage time (up to 50 days). Both barrier properties of the material and antioxidant capacity of the extract where analysed. Films with extract, with or without fibres, were highly effective in retarding oil oxidation due to the antioxidant capacity of the extract and its protective effect against UV radiation. [ES] Se ha estudiado la capacidad para prevenir la oxidación de aceite de girasol de diferentes materiales biodegradables basados en almidón mediante el envasado en bolsas monodosis. Los materiales fueron obtenidos con almidón de maíz y glicerol como plastificante (30% en peso respecto almidón), con un extracto antioxidante (0, 4, 6 y 8%, respecto al peso de almidón), ambos obtenidos de la paja de arroz. Se han caracterizado las propiedades de barrera al vapor de agua y al oxígeno y las ópticas (color y transmitancia UV-VIS) de los materiales, encontrando una mejora en la capacidad de barrera al vapor de agua y al oxígeno con la incorporación de las fibras, con y sin extracto activo. Este redujo la permeabilidad al oxígeno de los films, pero aumentó la permeabilidad al vapor de agua. Los films con extracto exhibieron alta capacidad para la absorción de la luz UV, y presentaron coloración. Se obtuvieron bolsas monodosis con los films con 0 y 8% de extracto y con y