Active antioxidant packaging films: Development and effect on lipid stability of brined sardines

Active antioxidant food packaging films were produced by the incorporation of ascorbic acid, ferulic acid, quercetin, and green tea extract into an ethylene vinyl alcohol copolymer (EVOH) matrix. The characterisation of the thermal and barrier properties of the developed film showed that the addition of these bioactive compounds did not greatly modify their properties. However, the presence of ascorbic and ferulic acids resulted in a significant decrease in water vapour permeability, possibly due to the high affinity for water of these substances. Exposure of the films to various food simulants showed that the release from the films was dependent on the type of food simulant and the antioxidant incorporated: in the aqueous food simulant, materials containing ascorbic acid produced the largest release; in the fatty food simulant, quercetin and green tea extract presented the best performance. The efficiency of the films developed was determined by real packaging applications of brined sardines. The evolution of the peroxide index and the malondialdehyde content showed that, in general, the films improved sardine stability. Films with green tea extract offered the best protection against lipid oxidation.