Simulation of Beef Tallow Based on Quinoa Protein-Stabilized Pickering Emulsion

In this study, high-internal phase Pickering emulsions (HIPPEs) were prepared by high speed shearing using quinoa protein isolate (QPI) as interfacial particles, corn oil as dispersed phase, and beef bone broth or beef powder solution as continuous phase, and their rheological properties, thermodynamic properties, color and volatile components were analyzed. The results showed that all 5 emulsions exhibited obvious shear thinning behavior of a pseudoplastic fluid, and their apparent viscosities decreased with the increase in shear rate. However, at the same shear rate, the emulsion with fish gelatin added to the aqueous phase showed the highest viscosity, which was more conducive to simulating the sticky taste of beef tallow. Addition of fish gelatin or starch into the aqueous phase significantly increased the storage modulus (G’), loss modulus (G”) and viscoelastic properties of Pickering emulsions, and the emulsion with fish gelatin had better viscoelastic properties and rheological properties closer to those of beef tallow than the emulsion with starch. Adding fish gelatin to the aqueous phase containing beef bone broth significantly increased the brightness and whiteness of Pickering emulsion (P < 0.05), whereas the opposite effect was observed when the aqueous phase was beef powder solution. Moreover, adding starch or fish gelatin into the aqueous phase could significantly increase the melting point of quinoa protein-stabilized Pickering emulsion. The results of gas chromatography-mass spectrometry (GC-MS) showed that using beef bone broth as the aqueous phase increased the contents of flavor components such as hexanal, 4-isopropyl toluene, and pentadecylene, imparting the emulsion with part of the flavor of beef tallow. The composition of flavor components in the emulsion with beef powder solution was similar to that in the emulsion with beef bone broth, but the content of flavor compounds was lower in the emulsion with beef powder solution than with beef bone broth. In summary, quinoa protein-stabilized Pickering emulsion with an aqueous phase containing bovine bone broth and fish gelatin showed similar rheological properties, appearance and volatile flavor composition to beef tallow, and it possessed higher melting point, showing its potential and sustained research value in simulating saturated fat.