Marine sulfated polysaccharide affects the formation mechanism of gelatin emulsion-based oleogels

Abstract

Protein-polysaccharide delivery systems function as a promising tool to deliver bioactive ingredients aiming to improve their solubility and bioavailability. In this study, gelatin (Gel) and κ-carrageenan (Car) were used to evaluate the characteristics of the Gel-Car emulsion and the emulsion-templated oleogels. Results showed that Car addition significantly reduced the particle size and increased the potential absolute value during emulsion storage, especially for Gel-0.5% Car and Gel-1.0% Car emulsions, indicating Car addition enhanced the emulsion's stability. The emulsions' rheological results indicated that all the emulsions exhibited weak gel-like behavior dominated by elasticity, suggesting Car addition improved the emulsions' shear resistance and viscoelasticity. The emulsions' instability indices were Gel (0.034), Gel-0.1% Car (0.026), Gel-0.5% Car (0.013), and Gel-1.0% Car (0.011), indicating Car addition enhanced the emulsions' stability. For oleogels, Car addition significantly reduced the oil loss rate, delayed the thermal degradation, and improved the viscoelasticity, shear resistance, thixotropic recovery properties, and high-temperature resistance, especially for Gel-1.0% Car oleogel. The stability analysis exhibited that Car addition improved the oleogels' stability, with Gel-0.5% Car oleogel showing the best stability. FFA release was Gel (25.22%), Gel-0.1% Car (26.86%), Gel-0.5% Car (31.38%), and Gel-1.0% Car (39.57%), suggesting Car addition promoted the rapid release of FFA during oleogels digestion. Results above indicated that Gel-Car oleogels exhibited good structural stability and high gel strength, which provide a theoretical basis and new ideas for the preparation of oleogels from protein-marine sulfated polysaccharides using the emulsion template method for food industrial application.