Effect of the gelatin extraction method from tilapia skin and its application as a coating

Abstract

The objective of this study was to analyze gelatins extracted from tilapia (Oreochromis niloticus) skin and evaluate its effect as a coating on fish fillets of the same species. Four gelatin extractions from tilapia skins were prepared in acidic and alkaline conditions, followed by filtration and freeze drying. The samples were analyzed for moisture, lipids, ash, proteins, color parameters, viscosity, spectrophotometry and the coatings made with fish gelatin (FG) and commercial gelatin (CG) were sensorially tested. The protein content and the viscosity of the FG were influenced by the extraction method. The fillets coated with FG showed less moisture than those coated with CG. The sensorial acceptance of the fillets was not influenced by the use of the coatings. Therefore, the use of fish gelatin appears as a sustainable alternative to use tilapia skin after disposal in industrial processing.