Sapatinha, MariaCamacho, CarolinaPais-Costa, Antónia JulianaFernando, Ana LuísaMarques, AntónioPires, Carla2025-07-042025-07-042025-011660-3397PURE: 110603056PURE UUID: 5ae3ea0f-7769-480e-a828-cd825e4ae259Scopus: 85216765998PubMed: 39852515WOS: 001404256800001ORCID: /0000-0001-9270-3982/work/187257690http://hdl.handle.net/10362/184832This work was developed within the scope of the “BLUE BIOECONOMY INNO- VATION PACT” (Project No. C644915664-00000026) funded by NextGenerationEU, under the incentive of the “Agenda for Business Innovation” of the recovery and resilience plan (PRR). © 2024 by the authors. Licensee MDPI, Basel, SwitzerlandCo-products from the frozen fish processing industry often lead to financial losses. Therefore, it is essential to transform these co-products into profitable goods. This study explores the production of fish protein hydrolysates (FPH) from three co-products: the heads and bones of black scabbardfish (Aphanopus carbo), the carcasses of gilthead seabream (Sparus aurata), and the trimmings of Nile perch (Lates niloticus). Four enzymatic hydrolysis systems were tested: an endopeptidase (Alcalase, A), an exopeptidase (Protana, P), two-stage hydrolysis with an endopeptidase followed by an exopeptidase (A + P), and a single stage with endo- and exopeptidase (AP). The results show that combined enzymatic treatments, especially single-stage Alcalase and Protana (AP), achieved high protein yields (80%) and enhanced degrees of hydrolysis (34 to 49%), producing peptides with lower molecular weights. FPH exhibited significant antioxidant activity, in 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) assays, with EC50 values below 5 mg/mL. Additionally, AP hydrolysates demonstrated over 60% angiotensin-converting enzyme (ACE) inhibition at 5 mg/mL, indicating potential antihypertensive applications. Antidiabetic and anti-Alzheimer activities were present, but at relatively low levels. AP hydrolysates, especially from gilthead seabream, proved to be the most promising. This study highlights the value of fish co-products as sources of functional peptides, contributing to waste reduction, and their potential applications in food, agriculture, and nutraceuticals.1414584engAlcalaseanti-hypertensiveantioxidantbioactive compoundsmolecular weight distributionProtanasequential hydrolysissimultaneous hydrolysiszero wastePharmaceutical ScienceDrug DiscoveryPharmacology, Toxicology and Pharmaceutics (miscellaneous)SDG 12 - Responsible Consumption and ProductionSDG 9 - Industry, Innovation, and Infrastructurejournal article10.3390/md23010014https://www.scopus.com/pages/publications/85216765998