Formulation of Chitosan/Gelatin/Pequi Oil Emulsions: Rheological, Thermal, and Antimicrobial Properties

The search for bioactive compounds to replace synthetic food preservatives has been drawing attention in recent times, as it aims to solve the problem of food loss using a sustainable proposal better accepted by consumers. In this study, natural emulsions of chitosan/gelatin containing pequi oil (CGPO) were obtained. Thermogravimetric analysis allowed inferring the effects of the addition of pequi oil on the thermal stability of the polymeric network of chitosan and gelatin. Rheological deformation tests indicated that all emulsions were more elastic than viscous (G′ > G″), and that the increase in the pequi oil concentration enhanced their elastic behavior. Higher oil concentrations also led to lower gelation temperatures and increased the emulsion viscosity. In addition, emulsions stabilized by CG had long-term storage stability. CGPO emulsions showed a better antimicrobial activity against Staphylococcus aureus when compared to CG, suggesting a synergism between the oil and chitosan in the desired antimicrobial protection. These results offer a strategy for the development and application of emulsions containing natural compounds, disclosing their potential as food additives.