A study on the synergistic interaction of pea protein isolate and whey protein isolate for enhancing the stability and quality of krill oil emulsion

Krill oil (KO) is an effective supplement for reducing cardiovascular risk and improving overall heart health, with consistent evidence of increased Omega-3 index levels in patients. In this study, a dual-protein of pea protein isolate (PPI) and whey protein isolate (WPI) was used to stabilize KO emulsion. The interaction between PPI and WPI was studied, and the physical properties of PPI-WPI-KO dual-protein emulsion and PPI-KO, WPI-KO single protein emulsions were compared. The results of fourier transform infrared (FTIR) spectroscopy, fluorescence and X-ray diffractionand (XRD) showed that the combination of PPI and WPI led to an increase in the random coil content and disordered structure. These changes improved the flexibility and ductility of the PPI-WPI dual-protein. Moreover, the PPI-WPI-KO emulsion exhibited greater stability compared to PPI-KO and WPI-KO emulsions. This was evidenced by a significant decrease in the particle size of the emulsions (from 4.24 ± 0.04 μm and 4.20 ± 0.04 μm to 4.04 ± 0.04 μm) and a significant increase in the ζ-potential (absolute value from 17.03 ± 0.57 mV and 17.77 ± 0.21 mV to 18.87 ± 0.38 mV) ( p  < 0.05). Furthermore, microstructure analysis showed that the presence of PPI-WPI dual-protein contributed to the dispersion and homogeneity of the KO emulsion. This study holds significant implication for the development of stabilized KO emulsions using dual proteins, as it can improve the quality of the emulsions and expand their applications in the food industry.