Seabuckthorn seed protein concentrate: a novel seed protein; emulsifying properties as affected by ultrasonication and enzymatic hydrolysis

The study investigated the influence of ultrasonication and enzymatic hydrolysis on emulsifying properties of Seabuckthorn seed protein concentrate (SSPC). Sonication was done at 24 kHz (50% amplitude) for different time combinations (15, 45 and 75 min), and enzymatic hydrolysis of SSPC was done using pepsin, trypsin and protamex, resulting in different SSPC emulsions. All the emulsions were characterised to ascertain the particle size distribution, pH stability, temperature stability and rheology. Hydrolysed SSPC was also characterised for the respective degree of hydrolysis by pepsin, trypsin and protamex. The pepsin revealed the highest degree of hydrolysis among the proteases, followed by trypsin and protamex. The ultrasonicated SSPC and SSPC hydrolysate emulsions showed unimodal particle size distribution except for pepsin hydrolysate emulsions which showed bimodal size distribution of particles. The variation in pH from 2 to 5 increased the particle size, while at higher pH (7-10), the particle size decreased for all the emulsions. The increase in temperature from 25 degrees C to 85 degrees C increased the droplet size of all the emulsions except for protamex at 75 min, which showed a relatively smaller droplet size than other proteases. All the emulsions displayed shear thinning behaviour, however, the pepsin-treated emulsions showed the highest consistency index and K-value. The resulting ultrasonicated and different protease-treated SSPC emulsions can be suitable green and nontoxic alternatives to synthetic emulsifiers used in the food industry.

Automated summary

This study investigated the effects of ultrasonication and enzymatic hydrolysis on the emulsifying properties of Seabuckthorn seed protein concentrate (SSPC). The results showed that ultrasonication and enzymatic hydrolysis can alter the particle size distribution, pH stability, temperature stability, and rheology of SSPC emulsions. Pepsin had the highest degree of hydrolysis among the proteases, and ultrasonicated and protease-treated SSPC emulsions exhibited unimodal particle size distribution.