The present work has an important advantage compared to most of the above-mentioned references, which is the non-volatile, non-aromatic nature of the antioxidant agents, which should reduce any effect on the sensory quality of the final product. Ascorbic acid is one of the most used antioxidants in the food industry. It is water-soluble, but it is easily oxidised and degraded when exposed to oxygen, metals, light or heat. Ferulic acid is a component of lignocelluloses, and serves to crosslink lignin and polysaccharides, giving rigidity to cell walls. It is found in seeds of plants, such as rice, wheat and oats. Ascorbic and ferulic acid owe their antioxidant activity to the hydroxyl groups. Catechins are the principal components of green tea extract and, like quercetin, are bioflavonoids. They present a well-known antioxidant activity due to the catechol group, among other substituents.
The resulting materials were characterised to analyse the effect of the addition of the antioxidants and the casting process on EVOH functional properties, and their antioxidant activity in food was determined by monitoring the release of active agents into different food simulants, analysing the scavenging capacity of radical oxidising compounds, as well as their application as sardine packaging. The lipid oxidation of sardines was monitored by peroxide and TBARS values.