Tannic acid enhanced the emulsion stability, rheology and interface characteristics of Clanis Bilineata Tingtauica Mell protein stabilised oil-in-water emulsion

Clanis Bilineata Tingtauica Mell Protein (CBTMP) was one of the new natural insect protein resources. However, due to its strong surface hydrophobicity and poor emulsion stability, its application has greatly been limited. In this study, Pickering emulsions were prepared by CBTMP-Tannic acid (CBTMP-TA) particles and soybean oil (phi = 50%). The presence of TA significantly increased the zeta-potential (from -23.5 +/- 0.73 to -29.23 +/- 0.58 mV) and three-phase contact angle (from 129.9 +/- 4.53 degrees to 87.27 +/- 3.20 degrees) of complex, especially the concentration of TA was 0.4 mm. Besides, the stability of emulsions was significantly improved according to the results of the droplet size and static multiple light scattering. Furthermore, rheological properties including viscosity, thixotropy and creep recovery were significantly enhanced, which indicated the formation of a more stable network structure. Interfacial behaviour (Interfacial tension, interfacial film viscoelasticity and diffusion rate) of emulsions was significantly changed, forming a more stable interfacial layer as TA content increased. The CBTMP-TA complex was adsorbed at the interface and the adsorption rate was also mainly affected by the content of TA. The study indicated CBTMP-TA compositions to enhance stability, rheological behaviours and interfacial characteristics, and demonstrated the potential applications of insect protein resources in food emulsion systems.