Caracterització i aplicació de pel·lícules de PBS i rapa de raïm per a l'envasament actiu d'aliments

Abstract

[ES] El raspón de uva es un subproducto de alta producción con un elevado potencial antioxidante que puede aprovecharse en el envasado de alimentos. Se incorporó este residuo previamente molido en películas de PBS que se obtuvieron por termocompresión. Se realizó una caracterización de las películas en cuanto a sus propiedades barrera al agua y al oxígeno, propiedades mecánicas, térmicas (DCS y TGA), ópticas y estructurales. Asimismo se realizó un ensayo acelerado de oxidación de aceite con el fin de evaluar el potencial efecto de las películas sobre la cinética de oxidación del alimento modelo.

[EN] In this work, three potentially antioxidant fillers from grape stalks were incorporated: ground stalks (RM), residue from subcritical water extraction at 170ºC and 180ºC (RE170 and RE180 respectively) in polybutylene succinate (PBS) to obtain 4 films: P (pure PBS, without filler), P-RM (PBS + ground stalk), PRE170 (PBS + extraction residue at 170ºC) and P-RE180 (PBS + extraction residue at 180ºC). These films were characterized for their properties relevant to their use as oxidation susceptible food packaging. The semi-crystalline nature of the films was observed using various techniques (FESEM microstructure, and Xray and FTIR spectra). The mechanical properties were slightly affected by the addition of fillers, which caused significant changes in the colour of the films. The thermal resistance of the films slightly improved due to the effect of the fillers. Water vapor permeability increased while oxygen permeability decreased with the incorporation of fillers. Single doses of film were formed to package sunflower oil stored under accelerated oxidation conditions. The films with fillers had a protective effect against the oxidation of the samples. However, this effect was not evident when the film samples were immersed in sunflower oil contained in polyethylene bags (without an oxygen barrier). The results point to the viability of these films for packaging foods susceptible to oxidative processes.