Influence of Paprika Oleoresin Addition on the Structural Properties of Soy Protein Isolate Films

Abstract

This work evaluated the effect of adding an emulsion containing paprika oleoresin on the properties of soy protein isolate films. Different proportions of the dispersed and continuous phases of the emulsion were studied to define the most stable emulsion to be added to the film. Three films were developed, containing soy protein isolate and glycerol (control film), and added paprika oleoresin emulsion in higher and lower concentrations (0.25% POR and 0.50% POR). The films were evaluated for colorimetric, structural, thermal properties, and molecular interactions. The addition of paprika oleoresin positively impacted the analyzed properties. Films with added oleoresin were more attractive, opaque and have a more resistant barrier to UV/Vis exposure. The emulsion was homogeneously and continuously dispersed, and the films were considered resistant due to the amorphous crystallinity pattern. Characteristic peaks of paprika oleoresin were evidenced by molecular interaction analysis. These results are promising for applications of the films in food products, highlighting the wrapping of meat products such as sausages or bologna.