Compression‐molded soy protein concentrate film incorporated with natural antioxidant: Storage stability and their effectiveness to improve the quality of fish products during refrigeration

The aim of the present research was to investigate aging stability of compression‐molded soy protein concentrate (SPC) film activated with red grape extract (RGE) (10%w/w SPC) and its effect as a food packaging material under refrigerated conditions. After 90 days at 25 ± 2°C and 65 ± 2% RH, control and active SPC films, kept unchanged transparency and color parameters, visual appearance, and water vapor permeability. Tensile properties varied significantly over time due to physical and chemical aging. The in vitro antioxidant activity of films dropped with time, remaining high after 90 days. SPC active film delayed bacterial growth and preserved mackerel chunks color parameters during storage. Samples packed with active SPC films received similar scores by a sensory panel to those packed with polyethylene, up to 15th d. The results demonstrated the potential of SPC‐based films as bio‐based alternatives for enhancing the quality of fish products during refrigeration storage. Practical applications The combined film obtained by adding RGE to the SPC formulation turned out to an effective packaging for food preservation. Our results open new perspectives to SPC‐RGE films as innovative environmentally safe packaging that can effectively delay the lipid oxidation and microbial growth in fish products, prolonging the shelf life and contributing to reduce the food spoilage and waste.