Fabrication and characterization of anti-inflammatory protein hydrolysates from salmon head

The rapid growth of Atlantic salmon processing generates large volumes of protein-rich by-products, particularly heads, which remain underutilized despite their high biochemical potential. In this study, salmon head-derived hydrolysates were produced via controlled enzymatic hydrolysis and structurally characterized to evaluate their anti-inflammatory potential. Compared with alkali extraction, enzymatic processing significantly increased soluble protein yield and enriched low-molecular-weight hydrolysates with high predicted anti-inflammatory and antioxidant potential, without apparent cytotoxicity. Functionally, the hydrolysates exhibited excellent cytocompatibility and markedly attenuated lipopolysaccharide (LPS)-induced inflammatory responses in RAW264.7 macrophages, including suppression of reactive oxygen species and nitric oxide production. In vivo, oral administration significantly alleviated dextran sulfate sodium (DSS)-induced colitis in mice, as evidenced by increased colon length, reduced disease activity index, and decreased expression of pro-inflammatory cytokines. These findings demonstrate that enzymatic valorization effectively converts salmon processing by-products into bioactive hydrolysates with potential applications, supporting the development of sustainable functional ingredients for inflammation-related disorders.