Marta Gallego

Hypertension and glycemia disorders are severe issues in public health, highlighting the urgent need for the discovery of natural bioactive agents with health benefits. In this sense, the present study examines camel skin gelatin hydrolyzate, obtained using Alcalase (GHA). GHA was first ultrafiltrated, and the low molecular weight fraction (<10 kDa) with the highest in vitro ACE and DPP-IV inhibitory activities (82.75% and 72.5%, respectively) was further purified by reversed-phase high-performance liquid chromatography. Among the resulting fractions (FI to FV), FIII and FIV were the most potent inhibitors against the ACE activity. Thus, they were analyzed by LC-MS/MS for peptide identification. In silico and peptidomic analyses revealed several novel peptide sequences. Molecular docking and MM-GBSA studies were subsequently performed to investigate the interactions and estimate the binding energies of the selected peptides with ACE and DPP-IV. Among the investigated peptides, GPSGPSGL and GPSGPR showed the strongest energy-binding scores against the studied enzymes with favorable interactions with their active sites. In conclusion, hydrolyzed camel skin gelatin is a promising source of multifunctional bioactive peptides and a potential natural ingredient for the management of hypertension and glycemic disorders.

The valorisation of meat by-products as sources of functional ingredients is gaining attention due to interest in sustainable protein recovery. This study explored the generation of antihypertensive peptides from bovine heart hydrolysates produced using Novozym®, Protamex®, and their combinations with the exopeptidase Protana™ Prime. Sequential enzyme treatments increased hydrolysis and amino acid release, while single endopeptidases yielded higher angiotensin-converting enzyme-I (ACE-I) and neprilysin (NEP) inhibitory activities, reaching 68.72% in the Protamex hydrolysate and 58.48% in the Novozym hydrolysate, respectively. Peptide profiling by LC–MS/MS identified 1251 peptides in the most bioactive fraction, mainly derived from muscle proteins. In silico analysis with PeptideRanker predicted 172 peptides with high bioactivity, whereas AHTpin supported antihypertensive activity for 109 peptides. MultiPep predicted ACE-inhibitory activity for NPPKFDK, VYPFPGPI, and VYPFPGPIPN, the latter showing the highest antihypertensive score (0.995). Additionally, KPPVVKW, LKPLPPK, and LKPRPPAR showed cell-penetrating peptide scores > 0.6, suggesting potential for cellular uptake. This study represents one of the first reports of NEP-inhibitory activity in bovine-derived peptides, highlighting heart hydrolysates as promising sources of multifunctional peptides for use in functional foods or nutraceuticals targeting cardiovascular health.

Fish consumption is rapidly increasing worldwide, generating significant by-products and waste that offer opportunities for reuse as food, cosmetic, or pharmaceutical ingredients aimed at a sustainable economy. This study evaluated the effect of simulated gastrointestinal digestion (GID) on the generation of antioxidant peptides from blue whiting muscle as well as from by-products hydrolysates obtained by alcalase hydrolysis and ultrasound-assisted alcalase hydrolysis. A comprehensive peptide profile was obtained by nano- or ultra-high-performance liquid chromatography coupled to mass spectrometry, identifying 1246 medium- and 415 short-sized peptides. In this context, GID led to a significant reduction in the number of identified medium-sized peptides in all samples. Concurrently, the quantity of identified short peptides increased in the digested muscle, whereas it remained largely unchanged in the by-product hydrolysates. Peptides containing proline, aspartate, histidine, tryptophan, or glycine residues showed high resistance to GID, and in silico analyses predicted 36 short-sized sequences as bioactives. Results of in vitro assays showed that antioxidant activity generally increased after GID when measured by ABTS radical-scavenging capacity and oxygen radical absorbance capacity assays, whereas it decreased in DPPH free radical–scavenging and ferric-reducing antioxidant power assays. These findings underline the antioxidant potential of peptides derived from both blue whiting muscle and by-products, which could be valorised as a sustainable source of functional ingredients, promoting circular economy and reducing waste in aquaculture.

Chicken feathers constitute a major by-product from the poultry industry, with a potential environmental impact and significant difficulties in their management. This study aimed to develop a sustainable method to hydrolyse chicken feathers and evaluate the effects of microwave (MW) irradiation pre-treatment in the generation of bioactive hydrolysates by simple or sequential hydrolysis with Alcalase. The hydrolysate with MW irradiation pre-treatment and Alcalase (2%, 2 h) (MWA) showed the highest overall antioxidant activity and neprilysin-inhibitory activity (55%), whereas samples without MW irradiation pre-treatment exerted the highest inhibitory activity of dipeptidyl peptidase IV (DPP IV) and angiotensin-converting enzyme (ACE-I), with values close to 50 and 70%, respectively. Mass spectrometry in tandem of bioactive hydrolysates was performed, and an in silico approach was used to characterise the obtained sequences. These results confirmed that MW irradiation pre-treatment improved Alcalase hydrolysis, leading to the generation of bioactive peptides with potential multifunctional properties, including antioxidant, antidiabetic, and antihypertensive activities. Moreover, this study highlights the potential of combining MW irradiation and enzymatic hydrolysis as a sustainable strategy for the revalorisation of chicken feathers.

Iron-fortified broad bean flours were obtained by vacuum impregnation during soaking.