Underutilised fish as sources of bioactive peptides with potential health benefits

Three species of underutilised fish: silver warehou, barracouta and Australian salmon, sampled in summer and winter, fresh and frozen, were cooked as fillets, subjected to simulated gastrointestinal digestion and bioactive enzymes extracted. Peptide profiles released by in vitro digestion varied with season and fresh or frozen state with seasonal variation most prominent. All peptides released from fish produced high levels of angiotensin converting enzyme (ACE) inhibition with warehou and barracouta more (p < 0.05) potent than salmon. Low levels of α-amylase inhibition and no α-glucosidase inhibition were observed from all fish. Trypsin inhibition was comparable among all fish with fresh fish having a greater effect than frozen. Allergenicity varied between fresh and frozen and remained relatively constant between seasons with the exception of silver warehou. The proximate nutrient composition of all species was similar