Structural characteristics and stability of salmon skin protein hydrolysates obtained with different proteases

The aim of this work is to evaluate the effects of Neutrase, Alcalase, Flavourzyme, and Protamex on the structural characteristics and stability of salmon skin protein (SSP) hydrolysates. The results suggested that Alcalase hydrolysate had the highest degree of hydrolysis (DH, 20.07%), the lowest molecular weight (<2000 Da), and more hydrophobic amino acids. Structural characterization demonstrated that the surface hydrophobicity, α-helical, and β-turn of the hydrolysates were significantly higher than those of salmon skin protein. Alcalase hydrolysate showed superior antioxidant activity to other hydrolysates. All SSP hydrolysates had good stability against oxidation under thermal, pH 3–11, or high salinity conditions and enhanced antioxidant activity during gastrointestinal digestion. Consequently, SSP hydrolysates can be used as potential antioxidants in the food and pharmaceutical industries.