Characteristics of Films Prepared from Wheat Gluten and Phenolic Extracts from Porphyra haitanensis and Its Application for Salmon Preservation

Abstract

The effect of wheat gluten (WG)/phenolic extracts (PE) coating on the storage qualities of salmon fillets was studied. Porphyra haitanensis, belonging to red algae, possesses abundant phenolic compounds. Films were prepared by incorporating phenolic extracts (0, 0.5%, 0.75%, and 1.0%, w/v) from Porphyra haitanensis to WG. The PE showed strong antioxidant activities by scavenging DPPH and ABTS radicals. The increased addition of PE to WG film significantly increased tensile strength compared to that of WG film, but reduced water vapor permeability. The quality of salmon fillet stored at 4 °C from 0 to 9 days was decreased due to the oxidation of lipid and protein. However, the increased addition of PE to WG significantly reduced pH, TVB-N, TBA, peroxide value, total sulfhydryl content, and carbonyl content of salmon fillet compared to control salmon fillet. In addition, the increased addition of PE to WG also significantly improved water holding capacity, hardness, chewiness, and springiness of salmon fillet during storage compared to those of control salmon fillet. Taken together, this study showed phenolic extracts from Porphyra haitanensis improved wheat gluten-based film properties and further enhanced the qualities of coated salmon fillet during storage.