Protein Hydrolysates and Biopeptides: Production, Biological Activities, and Applications in Foods and Health Benefits. A Review

Quinoa protein and its hydrolysate improve the fatigue resistance of mice: a potential mechanism to relieve oxidative stress and inflammation and improve energy metabolism

Fatigue is commonly marked by reduced endurance and impaired function, often linked to overexertion and chronic conditions. Quinoa (Chenopodium quinoa Willd.), with its rich amino acids and resilience to harsh conditions, offers a novel strategy for combating fatigue. This study explored the antifatigue effects of quinoa protein (QPro) and its hydrolysate (QPH) in weight-loaded swimming mice. After 4 weeks of oral administration, QPro and QPH significantly prolonged swimming duration, reduced serum fatigue biomarkers (lactic acid, urea nitrogen, lactate dehydrogenase, creatine kinase), and elevated glycogen reserves in the liver and muscle. RT-qPCR analysis indicated that QPH activated hepatic gluconeogenesis via G6Pase and PEPCK signaling and enhanced mitochondrial function through PGC-1α/NRF1/TFAM signaling in muscle. Additionally, QPro and QPH boosted antioxidant defenses by improving antioxidant enzyme activity, reducing malondialdehyde through the Nrf2/HO-1 pathway, and suppressing inflammation by reducing TNF-α and IL-6 levels. Network pharmacology identified 31 key targets involved in energy metabolism and inflammation, providing novel insights into the molecular mechanisms underlying the antifatigue properties of quinoa peptides. These findings highlight the potential of QPro and QPH as natural and bioactive ingredients in functional foods for enhancing endurance and mitigating fatigue.

Production of Protein Hydrolysates from Cod Backbone Using Selected Enzymes: Evaluation of Antioxidative and Antimicrobial Activities of Hydrolysates

In the fish industry, up to 70% of all fish end up as side-streams such as backbones, heads, and viscera. To reduce the quantities of side-streams, a higher utilization degree of fish is needed. The aim of this study was to use cod backbone for an enzymatic production of bioactive hydrolysates with antioxidative and/or antimicrobial properties. Three different enzymes were applied (Alcalase, Neutrase, and Protamex), and hydrolyses were carried out within the enzyme's optima for pH and temperature for 0.5-6 h. The efficiency of the enzyme treatment was evaluated based on the protein extraction yield (PEY), the degree of hydrolysis (DH), and antioxidant activity using two different in vitro assays (1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging and iron chelation) and antimicrobial activity determined by minimum inhibitory concentration (MIC) and disk diffusion assays. Selected hydrolysates showing activity were evaluated with respect to amino acid composition and molecular weight. Alcalase-treated samples had the highest PEY (3 h, 63.5 ± 4.5%) followed by Protamex-treated samples (3 and 6 h; 51.9 ± 5.5% and 56.5 ± 4.5%); the lowest PEY was obtained with Neutrase (3 and 6 h; 30.4 ± 1.9% and 34.7 ± 3.4%). No clear relationship was observed between the PEY and DH. All hydrolysates had antioxidant activities. For radical scavenging activity, Protamex-treated hydrolysate showed the lowest IC50 (6 h, 2.1 ± 0.1 mg powder/mL) and had a molecular weight <10 kDa, whereas for iron chelation activity, the control samples (no enzyme added but heat-treated) showed a similar or lower IC50 with molecular weights of 200-10 kDa. Amino acid composition measured on selected hydrolysates suggested that not only the composition of amino acid but also sequence and size influence the properties. None of the hydrolysates showed antimicrobial activity. In summary, the results showed that protein hydrolysates with antioxidant activity can be produced from the cod backbone, which makes it possible to utilize this side-stream generated in the fish industry.

Advancements in Inactivation of Soybean Trypsin Inhibitors

Soybean Trypsin Inhibitors (STIs) in soy-based foods have negative effects on soybean protein digestion and pancreatic health of humans. The inactivation of STIs is a critical unit operation aimed at enhancing the nutritional properties of soy-based foods during processing. This paper reviews the structure of STIs and soybean proteins, as well as the mechanisms of digestion. Various technologies (physical, chemical, biological) have been used to inactivate STIs. Their parameter settings, operating procedures, advantages, and disadvantages are also described. Mechanisms of inactivation of STIs (Kunitz trypsin inhibitor (KTI) and Bowman-Birk inhibitor (BBI)) conformations under different treatments are clarified. In addition, emerging technologies, e.g., Ohmic Heating, Electron Beam Irradiation, Dielectric-Barrier Discharge, and probiotics, have demonstrated great potential to inactivate STIs. We advise that multiple emerging technologies should combine with other unit operating systems to maximize inactivation efficiency.

Microbial protease supplementation improves gastric emptying and protein digestive fate of beef for the elderly under dynamic in vitro digestion

Elderly individuals experience age-related declines in digestive function, which can hinder the digestion of dietary proteins and thereby negatively impact overall health. This study provides a comprehensive understanding of the protein digestive fate of beef with Protease-DS supplementation by analyzing gastric emptying behavior and amino acid and peptide profiles during a simulated in vitro elderly digestion process. The adult model exhibited superior gastric emptying capacity, with relatively rapid and early expulsion of gastric digesta into the intestinal segment. Additionally, the underperforming elderly model showed notable improvement in the emptying process with Protease-DS supplementation, achieving a rate of 0.0110 min-1, which was close to the adult model of 0.0125 min-1 and significantly faster than the elderly model of 0.0080 min-1. Protein digestibility in the elderly model was significantly enhanced with Protease-DS supplementation, increasing from 55.62 % to 63.60 %, approaching that of the adult model (69.60 %). Protease-DS significantly improved the essential amino acid score (EAAS), particularly for methionine + cysteine, phenylalanine + tyrosine, lysine, and leucine. Furthermore, it enhanced the release of unique polypeptide fragments, distinct from those in both the adult and elderly models, and demonstrated significant anti-amnesic and antithrombotic bioactive functions, highlighting its potential to improve memory and reduce blood clotting. This study provides guidance for elderly consumers on enhancing dietary protein digestion through protease supplementation, presenting it as an effective strategy to address protein deficiency and improve health and well-being.

Protein hydrolysates with ACE-I inhibitory activity from amaranth seeds fermented with Enterococcus faecium-LR9: Identification of peptides and molecular docking

One of the causes of hypertension is the activity of angiotensin-I converting enzyme (ACEI), making its inhibition a crucial strategy for controlling the disease. Protein hydrolysates are a known source of bioactive peptides that contribute to ACE-I inhibition. This study aims to evaluate the ACE-I inhibitory activity of amaranth seed hydrolysates after fermentation with Enterococcus faecium-LR9 and to compare it with Leuconostoc mesenteroides-18C6 and enzymatic hydrolysis (Alcalase®). The fermentation strategy with LR9 proved to be more effective in inhibiting ACE-I (79.1 ± 2.6 %) in vitro compared to 18C6 (68.0 ± 9.8 %) and enzymatic hydrolysis (69.4 ± 1.2 %). Consequently, these protein hydrolysates were subjected to in silico analysis, identifying 125 novel peptides. Bioinformatics and molecular docking analyses revealed 10 peptides with high ACE-I inhibitory potential. Among them, the IFQFPKTY and VIKPPSRAW peptides stood out. Therefore, E. faecium-LR9 is a promising strain for the release of bioactive peptides from seed storage proteins.

Atlantic salmon (Salmo salar) waste as a unique source of biofunctional protein hydrolysates: Emerging productions, promising applications, and challenges mitigation

The Atlantic salmon is an extremely popular fish for its nutritional value and unique taste among several fish species. Researchers are focusing on the utilization of Atlantic salmon waste for generating protein hydrolysates rich in peptides and amino acids and investigating their health benefits. Several technological approaches, including enzymatic, chemical, and the recently developed subcritical water hydrolysis, are currently used for the production of Atlantic salmon waste protein hydrolysates. Hydrolyzing various wastes, e.g., heads, bones, skin, viscera, and trimmings, possessing antioxidant, blood pressure regulatory, antidiabetic, and anti-inflammatory properties, resulting in applications in human foods and nutraceuticals, animal farming, pharmaceuticals, cell culture, and cosmetics industries. Furthermore, future applications, constraints several challenges associated with industrial hydrolysate production, including sensory, safety, and economic constraints, which could be overcome by suggested techno processing measures. Further studies are recommended for developing large-scale, commercially viable production methods, focusing on eradicating sensory constraints and facilitating large-scale application.

Valorization of fish processing by-products for protein hydrolysate recovery: Opportunities, challenges and regulatory issues

Protein-rich fish processing by-products, often called rest raw materials (RRM), account for approximately 60% of the total fish biomass. However, a considerable amount of these RRM is utilized for low-value products such as fish meal and silage. A promising and valuable approach for maximizing the utilization of RRM involves the extraction of bioactive fish protein hydrolysate (FPH). This review assesses and compares different hydrolyzation methods to produce FPH. Furthermore, the review highlights the purification strategy, nutritional compositions, and bioactive properties of FPH. Finally, it concludes by outlining the application of FPH in food products together with various safety and regulatory issues related to the commercialization of FPH as a protein ingredient in food. This review paves the way for future applications by highlighting efficient biotechnological methods for valorizing RRM into FPH and addressing safety concerns, enabling the widespread utilization of FPH as a valuable and sustainable source of protein.

The ultrasonic-assisted enzymatic extraction, characteristics and antioxidant activities of lychee nuclear polysaccharide

A response surface methodology (RSM) and one-factor method were established to investigate the optimum conditions for the extraction of lychee nuclear polysaccharides (LSP) by ultrasonic-assisted pectinase. The content of basic components in polysaccharides was determined. The antioxidant activity was well determined and compared the differences in the activities of the polysaccharides extracted by water extraction (LSP-HW) and those extracted at ultrasound-assisted enzyme (LSP-UAE). The activity of lychee nuclear polysaccharide increased with the increase of concentration. The anti-hydroxyl radical and anti-lipid peroxidation abilities of lychee nuclear polysaccharide were more excellent, and LSP-HW was slightly better than LSP-UAE in terms of activity, but the difference was not significant. In terms of solubility; LSP-HW without deproteinization was the best, followed by LSP-UAE, and the worst was LSP-UAE after deproteinization. The higher the glycoprotein content, the better the solubility of its polysaccharide. Compared with the existing extraction methods, this experiment greatly improved the extraction rate of lychee nuclear polysaccharides and further enriched the antioxidant activities of polysaccharides.

Exploring the Utilization of Bovine Blood as a Source of Antioxidant Peptide: Production, Concentration, Identification, and In Silico Gastrointestinal Digestion

This study delves into the pivotal industrial process of efficiently managing livestock waste. Specifically, the study concentrates on harnessing the potential of bovine blood through enzymatic hydrolysis to produce antioxidant peptides. The whole bovine blood sample, subjected to a 90°C heat treatment for 30 min, underwent hydrolysis utilizing various commercial enzymes, alcalase, neutrase, and papain. Through neutrase hydrolysis (BB-N), we identified optimized conditions crucial for achieving heightened antioxidant activities and 40% protein recovery. Ultrafiltration with a molecular weight cutoff of 3 kDa was employed to concentrate the BB-N peptide, demonstrating the highest antioxidant and protein yield. The gel electrophoresis profile confirmed the denaturation of key proteins like albumin, globulin, and fibrinogen before digestion, while the BB-N derived after digestion contained peptides below 16 kDa. Post-concentration, the permeation of UF-3 kDa underwent purification, and the peptide sequence was discerned using liquid chromatography with tandem mass spectrometry. The exploration identified nine novel peptides- IWAGK, VDLL, MTTPNK, MPLVR, KIII, LPQL, TVIL, DFPGLQ, and VEDVK. Notably, the IWAGK sequence emerged as the most potent antioxidant activity peptide. Subsequent in-silico gastrointestinal digestion predicted structural changes in these peptides. While IWAGK, VDLL, MPLVR, LPQL, TVIL, and DFPGLQ could be fragmented into bioactive dipeptides and tripeptides, MTTPNK, KIII, and VEDVK exhibited resistance, suggesting potential circulation through the bloodstream to reach the target organ. Consequently, our study explores the potential use of BB-N as a novel dietary ingredient with health benefits. In vivo studies are needed to validate and extend our findings.

Profiling Bioactive Components of Natural Eggshell Membrane (NEM) for Cartilage Protection and Its Protective Effect on Oxidative Stress in Human Chondrocytes

The current study aimed to investigate the physicochemical properties of the natural eggshell membrane (NEM) and its protective effects against H2O2-induced oxidative stress in human chondrocytes (SW-1353). Bioactive components from NEM related to cartilage were profiled, consisting of 1.1 ± 0.07% hyaluronic acid, 1.2 ± 0.25% total sulfated glycosaminoglycans as chondroitin sulfate, 3.1 ± 0.33% collagen, and 54.4 ± 2.40% total protein. Protein was hydrolyzed up to 43.72 ± 0.76% using in vitro gastro-intestinal digestive enzymes. Peptides eluted at 9.58, 12.46, and 14.58 min using nano-LC-ESI-MS were identified as TEW, SWVE, and VYL peptides with an M/Z value of 435.1874, 520.2402, and 394.2336, respectively. Radical scavenging activity of NEM at 10 mg/mL using the ABTS assay was revealed to be 2.1 times higher than that of the positive control. NEM treatment significantly enhanced cellular SOD expression (p < 0.05). Pre-treatment with NEM (0.1, 1, and 10 mg/mL) dose-dependently reduced H2O2-induced ROS levels in SW-1353. Cell live imaging confirmed that NEM pre-treatment led to a significant reduction in apoptosis expression compared to control. Results from the present study suggest that NEM rich in cartilage protective components including hyaluronic acid, collagen, and chondroitin antioxidative peptides could be a potential therapeutic agent for osteoarthritis (OA) by scavenging oxidative stress.

Bioactive Peptides from Corn (Zea mays L.) with the Potential to Decrease the Risk of Developing Non-Communicable Chronic Diseases: In Silico Evaluation

Studies have shown that corn (Zea mays L.) proteins, mainly α-zein, have the potential to act on therapeutic targets related to non-communicable chronic diseases, such as high blood pressure and type 2 diabetes. Enzymatic hydrolysis of proteins present in foods can result in a great diversity of peptides with different structures and possible bioactivities. A review of recent scientific research papers was performed to show evidence of the bioactive properties of corn peptides by in vitro assays. The α-zein amino acid sequences were identified in the UniProtKB protein database and then analyzed in the BIOPEP database to simulate enzymatic digestion and verify the potential biological action of the resulting peptides. The peptides found in the BIOPEP database were categorized according to the probability of presenting biological action using the PeptideRanker database. The aim was to use existing data to identify in silico the potential for obtaining biologically active peptides from α-zein, the main storage protein of corn. The analysis showed that the majority of peptide fragments were related to the inhibition of angiotensin-converting enzyme, followed by the inhibition of dipeptidyl peptidase IV and dipeptidyl peptidase III. Many drugs used to treat high blood pressure and type 2 diabetes work by inhibiting these enzymes, suggesting that corn peptides could be potential alternative agents. In vitro studies found that the primary bioactivity observed was antioxidative action. Both in vitro and in silico approaches are valuable for evaluating the bioactive properties resulting from protein hydrolysis, such as those found in α-zein. However, conducting in vitro studies based on prior in silico evaluation can be more efficient and cost-effective.

Identification of New Angiotensin-Converting Enzyme Inhibitory Peptides Isolated from the Hydrolysate of the Venom of Nemopilema nomurai Jellyfish

Recently, jellyfish venom has gained attention as a promising reservoir of pharmacologically active compounds, with potential applications in new drug development. In this investigation, novel peptides, isolated from the hydrolysates of Nemopilema nomurai jellyfish venom (NnV), demonstrate potent inhibitory activities against angiotensin-converting enzyme (ACE). Proteolytic enzymes-specifically, papain and protamex-were utilized for the hydrolysis under optimized enzymatic conditions, determined by assessing the degree of hydrolysis through the ninhydrin test. Comparative analyses revealed that papain treatment exhibited a notably higher degree of NnV hydrolysis compared to protamex treatment. ACE inhibitory activity was quantified using ACE kit-WST, indicating a substantial inhibitory effect of 76.31% for the papain-digested NnV crude hydrolysate, which was validated by captopril as a positive control. The separation of the NnV-hydrolysate using DEAE sepharose weak-anion-exchange chromatography revealed nine peaks under a 0-1 M NaCl stepwise gradient, with peak no. 3 displaying the highest ACE inhibition of 96%. The further purification of peak no. 3 through ODS-C18 column reverse-phase high-performance liquid chromatography resulted in five sub-peaks (3.1, 3.2, 3.3, 3.4, and 3.5), among which 3.2 exhibited the most significant inhibitory activity of 95.74%. The subsequent analysis of the active peak (3.2) using MALDI-TOF/MS identified two peptides with distinct molecular weights of 896.48 and 1227.651. The peptide sequence determined by MS/MS analysis revealed them as IVGRPLANG and IGDEPRHQYL. The docking studies of the two ACE-inhibitory peptides for ACE molecule demonstrated a binding affinity of -51.4 ± 2.5 and -62.3 ± 3.3 using the HADDOCK scoring function.

Evaluation of Prebiotic and Health-Promoting Functions of Honeybee Brood Biopeptides and Their Maillard Reaction Conjugates

This study addresses the growing interest in natural functional ingredients by evaluating the prebiotic and health-promoting functions of honeybee brood biopeptides (HBb-Bps) and their conjugates. The purpose was to investigate their antioxidant activities, enzyme inhibition properties, and effects on probiotic growth and short-chain fatty acid (SCFA) production. The HBb-Bps were conjugated with honey, glucose, and fructose via the Maillard reaction. Antioxidant activities were assessed using DPPH and ABTS assays. The inhibitory effects on amylase, pancreatic lipase, and the angiotensin-converting enzyme (ACE) were measured. Probiotic growth and SCFA production were evaluated using L. plantarum TISTR846, and L. lactis TISTR1464. The HBb-Bps and their conjugates exhibited enhanced antioxidant activities post-Maillard reaction. They showed moderate enzyme inhibition, which decreased after conjugation. However, ACE inhibition increased with conjugation. The HBb-Bps significantly promoted probiotic growth and SCFA production, with further enhancement by the Maillard reaction. Overall, the HBb-Bps and their conjugates demonstrate significant prebiotic and health-promoting functions, suggesting their potential as natural ingredients in functional foods and nutraceuticals. Further research should focus on the in vivo effects and, given their solubility and stability these biopeptides could be incorporated into functional food formulations, such as health beverages, protein bars, and other fortified foods designed to deliver specific health benefits.

Contemporary Speculations and Insightful Thoughts on Buckwheat-A Functional Pseudocereal as a Smart Biologically Active Supplement

Today, food scientists are interested in more rational use of crops that possess desirable nutritional properties, and buckwheat is one of the functional pseudocereals that represents a rich source of bioactive compounds (BACs) and nutrients, phytochemicals, antimicrobial (AM) agents and antioxidants (AOs), which can be effectively applied in the prevention of malnutrition and celiac disease and treatment of various important health problems. There is ample evidence of the high potential of buckwheat consumption in various forms (food, dietary supplements, home remedies or alone, or in synergy with pharmaceutical drugs) with concrete benefits for human health. Contamination as well as other side-effects of all the aforementioned forms for application in different ways in humans must be seriously considered. This review paper presents an overview of the most important recent research related to buckwheat bioactive compounds (BACs), highlighting their various functions and proven positive effects on human health.

A Novel Workflow for In Silico Prediction of Bioactive Peptides: An Exploration of Solanum lycopersicum By-Products

Resource-intensive processes currently hamper the discovery of bioactive peptides (BAPs) from food by-products. To streamline this process, in silico approaches present a promising alternative. This study presents a novel computational workflow to predict peptide release, bioactivity, and bioavailability, significantly accelerating BAP discovery. The computational flowchart has been designed to identify and optimize critical enzymes involved in protein hydrolysis but also incorporates multi-enzyme screening. This feature is crucial for identifying the most effective enzyme combinations that yield the highest abundance of BAPs across different bioactive classes (anticancer, antidiabetic, antihypertensive, anti-inflammatory, and antimicrobial). Our process can be modulated to extract diverse BAP types efficiently from the same source. Here, we show the potentiality of our method for the identification of diverse types of BAPs from by-products generated from Solanum lycopersicum, the widely cultivated tomato plant, whose industrial processing generates a huge amount of waste, especially tomato peel. In particular, we optimized tomato by-products for bioactive peptide production by selecting cultivars like Line27859 and integrating large-scale gene expression. By integrating these advanced methods, we can maximize the value of by-products, contributing to a more circular and eco-friendly production process while advancing the development of valuable bioactive compounds.

Subcritical Water Extraction of Undaria pinnatifida: Comparative Study of the Chemical Properties and Biological Activities across Different Parts

The subcritical water extraction of Undaria pinnatifida (blade, sporophyll, and root) was evaluated to determine its chemical properties and biological activities. The extraction was conducted at 180 °C and 3 MPa. Root extracts exhibited the highest phenolic content (43.32 ± 0.19 mg phloroglucinol/g) and flavonoid content (31.54 ± 1.63 mg quercetin/g). Sporophyll extracts had the highest total sugar, reducing sugar, and protein content, with 97.35 ± 4.23 mg glucose/g, 56.44 ± 3.10 mg glucose/g, and 84.93 ± 2.82 mg bovine serum albumin (BSA)/g, respectively. The sporophyll contained the highest fucose (41.99%) and mannose (10.37%), whereas the blade had the highest galactose (48.57%) and glucose (17.27%) content. Sporophyll had the highest sulfate content (7.76%). Key compounds included sorbitol, glycerol, L-fucose, and palmitic acid. Root extracts contained the highest antioxidant activity, with IC50 values of 1.51 mg/mL (DPPH), 3.31 mg/mL (ABTS+), and 2.23 mg/mL (FRAP). The root extract exhibited significant α-glucosidase inhibitory activity with an IC50 of 5.07 mg/mL, indicating strong antidiabetic potential. The blade extract showed notable antihypertensive activity with an IC50 of 0.62 mg/mL. Hence, subcritical water extraction to obtain bioactive compounds from U. pinnatifida, supporting their use in functional foods, cosmetics, and pharmaceuticals is highlighted. This study uniquely demonstrates the variation in bioactive compound composition and bioactivities across different parts of U. pinnatifida, providing deeper insights. Significant correlations between chemical properties and biological activities emphasize the use of U. pinnatifida extracts for chronic conditions.

Preparation and identification of antioxidant peptides from Quasipaa spinosa skin through two-step enzymatic hydrolysis and molecular simulation

Frog skin, a by-product of Quasipaa Spinosa farming, is rich in protein and potentially a valuable raw material for obtaining antioxidant peptides. This study used papain combined with acid protease to digest frog skin in a two-step enzymatic hydrolysis method. Based on a single factor and response surface experiments, experimental conditions were optimized, and the degree of hydrolysis was 30 %. A frog skin hydrolysate (QSPH-Ⅰ-3) was obtained following ultrafiltration and gel filtration chromatography. IC50 for DPPH, ABTS, and hydroxyl radical scavenging capacities were 1.68 ± 0.05, 1.20 ± 0.14 and 1.55 ± 0.11 mg/mL, respectively. Peptide sequences (17) were analyzed and, through molecular docking, peptides with low binding energies for KEAP1 were identified, which might affect the NRF2-KEAP1 pathway. These findings suggest protein hydrolysates and antioxidant peptide derivatives might be used in functional foods.

Sacha Inchi (Plukenetia volubilis L.) Protein Hydrolysate as a New Ingredient of Functional Foods

Sacha inchi (Plukenetia volubilis L.) is an under-exploited crop with great potential due to its nutritional and medicinal characteristics. A Sacha inchi protein isolate (SII), obtained from defatted Sacha inchi flour (SIF), was hydrolyzed by Bioprotease LA 660 under specific conditions. The hydrolysates were characterized chemically, and their digestibility and antioxidant capacity were evaluated by in vitro cell-free experiments to select the hydrolysate with major antioxidant activity. Sacha inchi protein hydrolysate at 20 min (SIH20B) was selected, and the anti-inflammatory capacity was evaluated by RT-qPCR and ELISA techniques, using two different doses in monocytes THP-1 stimulated with lipopolysaccharide (LPS). The results obtained showed that the in vitro administration of SIH20B down-regulated the TNF-α gene and reduced the release of this cytokine, whereas the anti-inflammatory cytokines IL-10 and IL-4 were up-regulated in LPS-stimulated monocytes and co-administrated with SIH20B. The peptides contained in SIH20B were identified, and the 20 more relatively abundant peptides with a mass by 1 kDa were subjected to in silico analysis to hypothesize those that could be responsible for the bioactivity reported in the hydrolysate. From the identified peptides, the peptides AAGALKKFL and LGVKFKGGL, among others, are proposed as the most biologically actives. In conclusion, SIH20B is a novel, natural source of high-value-added biopeptides that could be used as an ingredient in formulations of food or nutraceutical compounds.

Employing fruit juices to hydrolyze edible bird's nest and enhance the antioxidant, anti-tyrosinase, and wound-healing activities of the hydrolysates

Enzymatic hydrolysis of edible bird's nest (EBN) has attracted great interest in both scientific and commercial fields due to the enhancement of solubility and nutraceutical values. The present study attempted to investigate the hydrolysis of EBN with papaya (Carica papaya L.), pineapple (Ananas comosus (L.) Merr.), and cantaloupe (Cucumis melo L.) juices as well as two commercial enzymes papain and bromelain. Our analysis revealed that EBN hydrolysis with pineapple juice and bromelain produced a degree of hydrolysis (DH) value of approximately 27 % while it was about 25 % for the hydrolysis with cantaloupe juice and 22 % for the hydrolysis with papaya juice and papain after 4 h of treatment. When EBN was digested by fruit juices and enzymes, the protein solubility and free sialic acid content were increased and the highest values were achieved for EBN hydrolysis with pineapple juice and bromelain (estimately 11 mg/mL of soluble protein and 18 g/kg of free sialic acid). The ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase capacities were higher in the EBN hydrolysates by papaya juice (IC50 of 0.034, 0.108, and 0.419 mg/mL, respectively), pineapple juice (IC50 of 0.025, 0.045, and 0.190 mg/mL, respectively), and cantaloupe juice (IC50 of 0.031 mg/mL, 0.056, and 0.339 mg/mL, respectively) than in the hydrolysates by unhydrolyzed EBN (IC50 of 0.094, 0.366, and 1.611 mg/mL, respectively). An improvement in ABTS•+-scavenging, •OH-scavenging, and anti-tyrosinase abilities was also observed for the hydrolysates by papain (IC50 of 0.041, 0.129, and 0.417 mg/mL, respectively) and bromelain (IC50 of 0.025, 0.069, and 0.336 mg/mL, respectively) but in a lesser extent as compared to the hydrolysates by respective papaya and pineapple juices. Noticeably, the EBN hydrolysates by fruit juices remarkably enhanced the wound closure in human fibroblasts by about 1.4-1.8 times after 24 h of treatment whereas this property was insignificant in the hydrolysates by enzymes. As papaya, pineapple, and cantaloupe juices are easily obtainable and have pleasant flavors, our results provide a possible method to hydrolyze EBN and apply the resultant hydrolysates in functional food products.

Unlocking the Therapeutic Potential of a Manila Clam-Derived Antioxidant Peptide: Insights into Mechanisms of Action and Cytoprotective Effects against Oxidative Stress

Reactive oxygen species (ROS) are implicated in various pathological conditions due to their ability to induce oxidative damage to cellular components. In this study, we investigated the antioxidant properties of a peptide isolated from the hydrolysate of Manila clam (Ruditapes philippinarum) muscle. Purification steps yielded RPTE2-2-4, exhibiting potent scavenging activities against DPPH•, HO•, and O2•-, akin to Vitamin C. Structural analysis showed that the isolated peptide, LFKKNLLTL, exhibited characteristics associated with antioxidant activity, including a short peptide length and the presence of aromatic and hydrophobic amino acid residues. Moreover, our study demonstrated the cytoprotective effects of the peptide against H2O2-induced oxidative stress in HepG2 cells. Pretreatment with the peptide resulted in a dose-dependent reduction in intracellular ROS levels and elevation of glutathione (GSH) levels, indicating its ability to modulate cellular defense mechanisms against oxidative damage. Furthermore, the peptide stimulated the expression of the cytoprotective enzyme heme oxygenase-1 (HO-1), further reinforcing its antioxidant properties. Overall, our findings highlight the potential of the Manila clam-derived peptide as a natural antioxidant agent with therapeutic implications for oxidative stress-related diseases. Further investigation into its mechanisms of action and in vivo efficacy is warranted to validate its therapeutic potential.

Sesame Seeds: A Nutrient-Rich Superfood

Sesame seeds (Sesamum indicum L.) have been cultivated for thousands of years and have long been celebrated for their culinary versatility. Beyond their delightful nutty flavor and crunchy texture, sesame seeds have also gained recognition for their remarkable health benefits. This article provides an in-depth exploration of the numerous ways in which sesame seeds contribute to overall well-being. Sesame seeds are a powerhouse of phytochemicals, including lignans derivatives, tocopherol isomers, phytosterols, and phytates, which have been associated with various health benefits, including the preservation of cardiovascular health and the prevention of cancer, neurodegenerative disorders, and brain dysfunction. These compounds have also been substantiated for their efficacy in cholesterol management. Their potential as a natural source of beneficial plant compounds is presented in detail. The article further explores the positive impact of sesame seeds on reducing the risk of chronic diseases thanks to their rich polyunsaturated fatty acids content. Nevertheless, it is crucial to remember the significance of maintaining a well-rounded diet to achieve the proper balance of n-3 and n-6 polyunsaturated fatty acids, a balance lacking in sesame seed oil. The significance of bioactive polypeptides derived from sesame seeds is also discussed, shedding light on their applications as nutritional supplements, nutraceuticals, and functional ingredients. Recognizing the pivotal role of processing methods on sesame seeds, this review discusses how these methods can influence bioactive compounds. While roasting the seeds enhances the antioxidant properties of the oil extract, certain processing techniques may reduce phenolic compounds.

Plant-based proteins from agro-industrial waste and by-products: Towards a more circular economy

There is a pressing need for affordable, abundant, and sustainable sources of proteins to address the rising nutrient demands of a growing global population. The food and agriculture sectors produce significant quantities of waste and by-products during the growing, harvesting, storing, transporting, and processing of raw materials. These waste and by-products can sometimes be converted into valuable protein-rich ingredients with excellent functional and nutritional attributes, thereby contributing to a more circular economy. This review critically assesses the potential for agro-industrial wastes and by-products to contribute to global protein requirements. Initially, we discuss the origins and molecular characteristics of plant proteins derived from agro-industrial waste and by-products. We then discuss the techno-functional attributes, extraction methods, and modification techniques that are applied to these plant proteins. Finally, challenges linked to the safety, allergenicity, anti-nutritional factors, digestibility, and sensory attributes of plant proteins derived from these sources are highlighted. The utilization of agro-industrial by-products and wastes as an economical, abundant, and sustainable protein source could contribute towards achieving the Sustainable Development Agenda's 2030 goal of a "zero hunger world", as well as mitigating fluctuations in food availability and prices, which have detrimental impacts on global food security and nutrition.

Effect of enzymolysis combined with Maillard reaction treatment on functional and structural properties of gluten protein

In this work, the modified gluten was prepared by enzymolysis combined with Maillard reaction (MEG), and its functional and structural properties were investigated. The result showed that the maximum foamability of MEG was 19.58 m2/g, the foam stability was increased by 1.8 times compared with gluten, and the solubility and degree of graft were increased to 44.4 % and 28.1 % at 100 °C, whereas the content of sulfhydryl group decreased to 0.81 μmol/g. The scavenging ability on ABTS+radical and DPPH radical of MEG was positively correlated with reaction temperature, and the maximum values were 86.57 % and 71.71 % at 140 °C, respectively. Furthermore, the fluorescence quenching effect of tryptophan and tyrosine residues was enhanced, while the fluorescence intensity decreased with the temperature increase. Scanning electron microscopy revealed that the surface of enzymatically hydrolyzed-gluten became smooth and the cross section became straightened, while MEG turned smaller and irregular approaching a circular structure. FT-IR spectroscopy showed that enzymatic hydrolysis promoted the occurrence of more carbonyl ammonia reactions and the formation of precursors of advanced glycosylation end products. These results provide a feasible method for improving the structure and functional properties of gluten protein.

Recent Trends in the Application of Oilseed-Derived Protein Hydrolysates as Functional Foods

Oilseed-derived proteins have emerged as an excellent alternative to animal sources for the production of bioactive peptides. The bioactivities exhibited by peptides derived from plant proteins encompass a wide range of health-promoting and disease-preventing effects. Peptides demonstrate potential capabilities in managing diseases associated with free radicals and regulating blood pressure. They can also exhibit properties that lower blood sugar levels and modify immune responses. In addition to their bioactivities, plant-derived bioactive peptides also possess various functional properties that contribute to their versatility. An illustration of this potential can be the ability of peptides to significantly improve food preservation and reduce lipid content. Consequently, plant-derived bioactive peptides hold great promise as ingredients to develop functional products. This comprehensive review aims to provide an overview of the research progress made in the elucidation of the biological activities and functional properties of oilseed-derived proteins. The ultimate objective is to enhance the understanding of plant-derived bioactive peptides and provide valuable insights for further research and use in the food and medicine industries.

Protein Hydrolysate from Underutilized Legumes: Unleashing the Potential for Future Functional Foods

Proteins play a vital role in human development, growth, and overall health. Traditionally, animal-derived proteins were considered the primary source of dietary protein. However, in recent years, there has been a remarkable shift in dietary consumption patterns, with a growing preference for plant-based protein sources. This shift has resulted in a significant increase in the production of plant proteins in the food sector. Consequently, there has been a surge in research exploring various plant sources, particularly wild, and underutilized legumes such as Canavalia, Psophocarpus, Cajanus, Lablab, Phaseolus, and Vigna, due to their exceptional nutraceutical value. This review presents the latest insights into innovative approaches used to extract proteins from underutilized legumes. Furthermore, it highlights the purification of protein hydrolysate using Fast Protein Liquid Chromatography. This review also covers the characterization of purified peptides, including their molecular weight, amino acid composition, and the creation of three-dimensional models based on amino acid sequences. The potential of underutilized legume protein hydrolysates as functional ingredients in the food industry is a key focus of this review. By incorporating these protein sources into food production, we can foster sustainable and healthy practices while minimizing environmental impact. The investigation of underutilized legumes offers exciting possibilities for future research and development in this area, further enhancing the utilization of plant-based protein sources.

Green Biorefinery systems for the production of climate-smart sustainable products from grasses, legumes and green crop residues

Grasses, legumes and green plant wastes represent a ubiquitous feedstock for developing a bioeconomy in regions across Europe. These feedstocks are often an important source of ruminant feed, although much remains unused or underutilised. In addition to proteins, these materials are rich in fibres, sugars, minerals and other components that could also be used as inputs for bio-based product development. Green Biorefinery processes and initiatives are being developed to better capitalise on the potential of these feedstocks to produce sustainable food, feed, materials and energy in an integrated way. Such systems may support a more sustainable primary production sector, enable the valorisation of green waste streams, and provide new business models for farmers. This review presents the current developments in Green Biorefining, focusing on a broad feedstock and product base to include different models of Green Biorefinery. It demonstrates the potential and wide applicability of Green Biorefinery systems, the range of bio-based product opportunities and highlights the way forward for their broader implementation. While the potential for new products is extensive, quality control approval will be required prior to market entry.

Investigation of the optimal production conditions for egg white hydrolysates and physicochemical characteristics

This study aimed to investigate the potential of egg white protein hydrolysate (EWH) as a functional food by identifying the optimum production conditions for EWH with response surface methodology (the results of the sensory evaluation were considered as an essential quality indicator). At the same time, its physicochemical and biological activity was also evaluated. The optimal economic production conditions were selected: substrate concentration of 12.5%, enzyme content of 7.5%, and hydrolysis time at 100 min. The degree of hydrolysis (DH %) was 13.51%. In addition, to the better acceptance of the evaluation, it also helps to reduce the production cost of the protein hydrolysate, which is beneficial to future processing and applications. The antioxidant capacity experiments showed that EWH has good antioxidant activity, which presents a dose-dependent relationship. Hence, this study provides a theoretical basis for future research and application of EWH for processing applications, including dietary supplementation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-023-05708-0.

Neuroprotective Effects of a Novel Tetrapeptide SGGY from Walnut against H2O2-Stimulated Oxidative Stress in SH-SY5Y Cells: Possible Involved JNK, p38 and Nrf2 Signaling Pathways

SGGY, an antioxidant tetrapeptide identified from walnut protein hydrolysate in our previous study, has been suggested to possess the potential to alleviate oxidative stress in cells. In this paper, the neuroprotective effects of SGGY on H2O2-stimulated oxidative stress in SH-SY5Y cells and the underlying mechanisms were investigated. Results showed that SGGY alleviated H2O2-induced oxidative stress by decreasing the intracellular reactive oxygen species (ROS) level and altering the mitochondrial membrane potential (MMP), thereby inhibiting apoptosis and increasing cell viability. SGGY significantly restored antioxidant enzyme activities and reduced malondialdehyde (MDA) content accordingly. Moreover, SGGY promoted the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and suppressed the H2O2-induced activation of JNK and p38 mitogen-activated protein kinases (MAPKs). Taken together, these results suggested that SGGY protected SH-SY5Y cells from H2O2-provoked oxidative stress by enhancing the ability of cellular antioxidant defense, and the possible mechanism involved MAPKs and Nrf2 signaling pathways.

Isolation, identification, and mode of action of antibacterial peptides derived from egg yolk hydrolysate

Egg yolk is a coproduct of egg white processing. The protein hydrolysis of egg yolks to exhibit antimicrobial activity is a strategy for its valorization. The objective of this study is to fractionate antibacterial peptides from pepsin-hydrolyzed egg yolks using flash chromatography. In addition, the mode of actions of the fractionated peptides were elucidated and plausible antibacterial peptides were reported. The fraction 6 (F6) obtained from a C18-flash column exhibited antibacterial activity against Staphylococcus aureus ATCC 29213 and Salmonella typhimurium TISTR 292 at minimal inhibitory concentration (MIC) values of 0.5 to 1 mmol/L (Leucine equivalent). The fractionated peptides induced DNA leakage as monitored by 260 nm. Propidium iodide and SYTO9 staining observed under a confocal microscope suggested the disintegration of cell membranes. Synchrotron-based Fourier-transform infrared spectroscopy analysis revealed that the egg yolk peptides at 1 × MIC induced an alteration of phospholipids at cell membranes and modified conformation of intracellular proteins and nucleic acids. Scanning electron microscopy revealed obvious cell ruptures when S. aureus was treated at 1 × MIC for 4 h, whereas damage of cell membranes and leakage of intracellular components were also observed for the transmission electron microscopy. Egg yolk peptides showed no hemolytic activity in human erythrocytes at concentrations up to 4 mmol/L. Peptide identification by LC-MS/MS revealed 3 cationic and 10 anionic peptides with 100% sequence similarity to apolipoprotein-B of Gallus gallus with hydrophobicity ranging from 27 to 75%. The identified peptide KGGDLGLFEPTL exhibited the highest antibacterial activity toward S. aureus at MIC of 2 mmol/L. Peptides derived from egg yolk hydrolysate present significant potential as antistaphylococcal agents for food and/or pharmaceutical application.

Potential Application of High Hydrostatic Pressure on the Production of Hydrolyzed Proteins with Antioxidant and Antihypertensive Properties and Low Allergenicity: A Review

The high hydrostatic pressure (HHP) process has been studied for several applications in food technology and has been commercially implemented in several countries, mainly for non-thermal pasteurization and shelf-life extension of food products. HHP processing has been demonstrated to accelerate proteolytic hydrolysis at a specific combination of pressure and pressure-holding time for a given protein source and enzyme. The enzymatic hydrolysis of proteins is a well-known alternative to producing biologically active peptides, with antioxidant and antihypertensive capacity, from different food protein sources. However, some of these protein sources contain allergenic epitopes which are often not degraded by traditional hydrolysis. Moreover, the peptide profile and related biological activity of a hydrolysate depend on the protein source, the enzymes used, the parameters of the proteolysis process (pH, temperature, time of hydrolysis), and the use of other technologies such as HHP. The present review aims to provide an update on the use of HHP for improving enzymatic hydrolysis, with a particular focus on studies which evaluated hydrolysate antihypertensive and antioxidant capacity, as well as residual allergenicity. Overall, HHP has been shown to improve the biological properties of hydrolysates. While protein allergenicity can be reduced with traditional hydrolysis, HHP can further reduce the allergenicity. Compared with traditional hydrolysis methods, HHP-assisted protein hydrolysis offers a greater opportunity to add value to protein-rich products through conversion into high-end hydrolysate products with enhanced nutritional and functional properties.

Antioxidant peptides: Overview of production, properties, and applications in food systems

In recent years, several studies have reported the beneficial effects of antioxidant peptides in delaying oxidation reactions. Thus, a growing number of food proteins have been investigated as suitable sources for obtaining these antioxidant peptides. In this study, some of the most critical developments in the discovery of peptidic antioxidants are discussed. Initially, the primary methods to release, purify, and identify these antioxidant peptides from various food-derived sources are reviewed. Then, computer-based screening methods of the available peptides are summarized, and methods to interpret their structure-activity relationship are illustrated. Finally, approaches to the large-scale production of these bioactive peptides are described. In addition, the applications of these antioxidants in food systems are discussed, and gaps, future challenges, and opportunities in this field are highlighted. In conclusion, various food items can be considered promising sources to obtain these novel antioxidant peptides, which present various opportunities for food applications in addition to health promotion. The lack of in-depth data on the link between the structure and activity of these antioxidants, which is critical for the prediction of possible bioactive amino acid sequences and their potency in food systems and in vivo conditions (rather than in vitro systems), requires further attention. Consequently, future collaborative research activities between the industry and academia are required to realize the commercialization objectives of these novel antioxidant peptides.

Antioxidant, Anti-Diabetic, Anti-Obesity, and Antihypertensive Properties of Protein Hydrolysate and Peptide Fractions from Black Sesame Cake

A low-value by-product of cold-pressed sesame oil is defatted black sesame cake (DBSC). The remaining protein and essential amino acids may be utilized as a renewable biological source to produce bioactive products. The bioactivities of the protein hydrolysate from black sesame cake and its peptide fractions were examined in this study for in vitro antioxidant activity and inhibition of DPP-IV, ACE, α-amylase, α-glucosidase, and pancreatic lipase. By using Flavourzyme to hydrolyze DBSC, followed by ultrafiltration, fractions with peptide sizes of <3, 3−10, and >10 kDa were obtained. According to the findings, the products of DBSC could neutralize free radicals and prevent ferric ion redox reactions. The highest inhibitory effects were shown with low Mw peptides (<3 kDa) against ACE, DPP-IV, α-amylase, and α-glucosidase. DBSC has demonstrated potential as a nutraceutical or functional ingredient for preventing and treating disorders associated with free radicals, such as diabetes, hypertension, and hyperglycemia.

Effects of Physicochemical Characteristics and Storage Stability of Porcine Albumin Protein Hydrolysates in Pork Sausage

In this study, the physicochemical characteristics and storage stability of porcine albumin protein hydrolysates (PAPH) in sausage were evaluated. Four concentrations of PAPH were added to pork emulsion sausage (T1, 0.3%; T2, 0.6%; T3, 0.9%; T4, 1.2%) and compared to the control (CON, 0%). On day 0, proximate composition, cooking loss, and sensory evaluation were compared. Purge loss, color, texture profile analysis, shear force, free amino acids, lipid oxidation, microbial counts, and volatile basic nitrogen (VBN) were compared on day 0 and after 4 weeks of refrigeration. The content of essential amino acids and redness(a*) increased as the level of PAPH added increased (p<0.05). Also, the cooking loss was improved (p<0.05). However, lipid oxidation, microbial counts, and VBN were increased significantly during storage for 4 weeks (p<0.05). The findings indicated that the addition of PAPH improved cooking loss and the protein composition of sausages, but negatively affected storage stability.

Casein Lactose-Glycation of the Maillard-Type Attenuates the Anti-Inflammatory Potential of Casein Hydrolysate to IEC-6 Cells with Lipopolysaccharide Stimulation

During the thermal processing of dairy products, the Maillard reaction occurs between milk proteins and lactose, resulting in the formation of various products including glycated proteins. In this study, lactose-glycated casein was generated through the Maillard reaction between casein and lactose and then hydrolyzed by a trypsin preparation. The anti-inflammatory effect of the resultant glycated casein hydrolysate (GCH) was investigated using the lipopolysaccharide (LPS)-sitmulated rat intestinal epithelial (IEC-6) cells as a cell model and corresponding casein hydrolysate (CH) as a control. The results indicated that the preformed glycation enabled lactose conjugation to casein, which endowed GCH with a lactose content of 12.61 g/kg protein together with a lower activity than CH to enhance the viability value of the IEC-6 cells. The cells with LPS stimulation showed significant inflammatory responses, while a pre-treatment of the cells with GCH before LPS stimulation consistently led to a decreased secretion of three pro-inflammatory mediators, namely, IL-6, IL-1β and tumor necrosis factor-α (TNF-α) but an increased secretion of two anti-inflammatory mediators, including IL-10 and transforming growth factor-β (TGF-β), demonstrating the anti-inflammatory potential of GCH in LPS-stimulated cells. In addition, GCH up-regulated the expression of TLR4, p-p38, and p-p65 proteins in the stimulated cells, resulting in the suppression of NF-κB and MAPK signaling pathways. Collectively, GCH was mostly less efficient than CH to exert these assessed anti-inflammatory activities in the cells and more importantly, GCH also showed an ability to cause cell inflammation by promoting IL-6 secretion and up-regulating the expression of TLR4 and p-p65. The casein lactose-glycation of the Maillard-type was thereby concluded to attenuate the anti-inflammatory potential of the resultant casein hydrolysate. It is highlighted that the casein lactose-glycation of the Maillard-type might cause a negative impact on the bioactivity of casein in the intestine, because the glycated casein after digestion could release GCH with reduced anti-inflammatory activity.

Screening and Molecular Mechanisms of Novel ACE-Inhibitory Peptides from Gracilariopsis lemaneiformis

Candidate peptides with novel angiotensin-I-converting enzyme (ACE) inhibitor activity were obtained from hydrolysates of Gracilariopsis lemaneiformis by virtual screening method. Our results showed that G. lemaneiformis peptides (GLP) could significantly lower blood pressure in spontaneously hypertensive rats (SHR). At least 101 peptide sequences of GLP were identified by LC-MS/MS analysis and subjected to virtual screening. A total of 20 peptides with the highest docking score were selected and chemically synthesized in order to verify their ACE-inhibitory activities. Among them, SFYYGK, RLVPVPY, and YIGNNPAKG showed good effects with IC₅₀ values of 6.45 ± 0.22, 9.18 ± 0.42, and 11.23 ± 0.23 µmoL/L, respectively. Molecular docking studies revealed that three peptides interacted with the active center of ACE by hydrogen bonding, hydrophobic interactions, and electrostatic forces. These peptides could form stable complexes with ACE. Furthermore, SFYYGK, RLVPVPY, and YIGNNPAKG significantly reduced systolic blood pressure (SBP) in SHR. YIGNNPAKG exhibited the highest antihypertensive effect, with the largest decrease in SBP (approximately 23 mmHg). In conclusion, SFYYGK, RLVPVPY, and YIGNNPAKG can function as potent therapeutic candidates for hypertension treatment.

Potential Cosmetic Active Ingredients Derived from Marine By-Products

The market demand for marine-based cosmetics has shown a tremendous growth rate in the last decade. Marine resources represent a promising source of novel bioactive compounds for new cosmetic ingredient development. However, concern about sustainability also becomes an issue that should be considered in developing cosmetic ingredients. The fisheries industry (e.g., fishing, farming, and processing) generates large amounts of leftovers containing valuable substances, which are potent sources of cosmeceutical ingredients. Several bioactive substances could be extracted from the marine by-product that can be utilized as a potent ingredient to develop cosmetics products. Those bioactive substances (e.g., collagen from fish waste and chitin from crustacean waste) could be utilized as anti-photoaging, anti-wrinkle, skin barrier, and hair care products. From this perspective, this review aims to approach the potential active ingredients derived from marine by-products for cosmetics and discuss the possible activity of those active ingredients in promoting human beauty. In addition, this review also covers the prospect and challenge of using marine by-products toward the emerging concept of sustainable blue cosmetics.

DPP-IV Inhibitory Peptides GPF, IGL, and GGGW Obtained from Chicken Blood Hydrolysates

Blood is a meat by-product rich in proteins with properties that can be improved after hydrolysis, making it a sustainable alternative for use in the generation of bioactive peptides. The objective of this study was to identify dipeptidyl peptidase IV (DPP-IV) inhibitory peptides obtained from different chicken blood hydrolysates prepared using combinations of four different enzymes. Best results were observed for AP (2% Alcalase + 5% Protana Prime) and APP (2% Alcalase + 5% Protana Prime + 3% Protana UBoost) hydrolysates obtaining inhibition values of 60.55 and 53.61%, respectively, assayed at a concentration of 10 mg/mL. Free amino acids were determined to establish the impact of exopeptidase activity in the samples. A total of 79 and 12 sequences of peptides were identified by liquid chromatography and mass spectrometry in tandem (LC-MS/MS) in AP and APP samples, respectively. Nine of the identified peptides were established as potential DPP-IV inhibitory using in silico approaches and later synthesized for confirmation. Thus, peptides GPF, IGL, and GGGW showed good DPP-IV inhibitory activity with IC₅₀ values of 0.94, 2.22, and 2.73 mM, respectively. This study confirmed the potential of peptides obtained from chicken blood hydrolysates to be used as DPP-IV inhibitors and, therefore, in the control or modulation of type 2 diabetes.

Food Protein-Derived Antioxidant Peptides: Molecular Mechanism, Stability and Bioavailability

The antioxidant activity of protein-derived peptides was one of the first to be revealed among the more than 50 known peptide bioactivities to date. The exploitation value associated with food-derived antioxidant peptides is mainly attributed to their natural properties and effectiveness as food preservatives and in disease prevention, management, and treatment. An increasing number of antioxidant active peptides have been identified from a variety of renewable sources, including terrestrial and aquatic organisms and their processing by-products. This has important implications for alleviating population pressure, avoiding environmental problems, and promoting a sustainable shift in consumption. To identify such opportunities, we conducted a systematic literature review of recent research advances in food-derived antioxidant peptides, with particular reference to their biological effects, mechanisms, digestive stability, and bioaccessibility. In this review, 515 potentially relevant papers were identified from a preliminary search of the academic databases PubMed, Google Scholar, and Scopus. After removing non-thematic articles, articles without full text, and other quality-related factors, 52 review articles and 122 full research papers remained for analysis and reference. The findings highlighted chemical and biological evidence for a wide range of edible species as a source of precursor proteins for antioxidant-active peptides. Food-derived antioxidant peptides reduce the production of reactive oxygen species, besides activating endogenous antioxidant defense systems in cellular and animal models. The intestinal absorption and metabolism of such peptides were elucidated by using cellular models. Protein hydrolysates (peptides) are promising ingredients with enhanced nutritional, functional, and organoleptic properties of foods, not only as a natural alternative to synthetic antioxidants.

Protein Hydrolysates Derived from Animals and Plants—A Review of Production Methods and Antioxidant Activity

There is currently considerable interest on the use of animal, plant, and fungal sources in the production of bioactive peptides, as evidenced by the substantial body of research on the topic. Such sources provide cheap and environmentally friendly material as it often includes waste and by-products. Enzymatic hydrolysis is considered an efficient method of obtaining peptides capable of antioxidant activity. Those properties have been proven in terms of radical-scavenging capacity using the DPPH (1,1-diphenyl-2-picrylhydrazyl) and ABTS (2,2-azinobis-(3-ethyl-benzothiazoline-6-sulphonic acid)), hydroxyl and superoxide radical methods. Additionally, the reducing power, ferrous ion-chelating (FIC), ferric reducing antioxidant power (FRAP), and the ability of the protein hydrolysates to inhibit lipid peroxidation have also been explored. The results collected in this review clearly indicate that the substrate properties, as well as the conditions under which the hydrolysis reaction is carried out, affect the final antioxidant potential of the obtained peptides. This is mainly due to the structural properties of the obtained compounds such as size or amino acid sequences.

The Impact of COVID-19 Pandemic on Seafood Safety and Human Health

The coronavirus disease (COVID-19) pandemic caused several negative impacts on global human health and the world's economy. Food and seafood safety and security were among the principal challenges and causes of concern for the food industry and consumers during the spread of this global pandemic. This article focused on the effects of COVID-19 pandemic on potential safety issues with seafood products and their processing methods. Moreover, the potential impacts of coronavirus transmission through seafood on human health were evaluated. The role of authenticity, traceability, and antimicrobials from natural sources to preserve seafood and the possible interaction of functional foods on the human immune system are also discussed. Although seafood is not considered a principal vector of SARS-CoV-2 transmission, the possible infections through contaminated surfaces of such food products cannot be neglected. The positive effects of seafood consumption on possible immunity built up, and COVID-19 are also summarized.

Effect of a Dietary Supplement Combining Bioactive Peptides and Magnesium on Adjustment Disorder with Anxiety: A Clinical Trial in General Practice

Anxiety is a high frequency disorder in the general population. It is usually treated with benzodiazepines, which cause side effects and a dependence that could make withdrawal difficult. Alternative treatments are therefore needed to reduce the use of anxiolytics, particularly for adjustment disorder with anxiety. An observational, multicentre, prospective, longitudinal study has been conducted by general practitioners and one gynaecologist to evaluate the efficacy of a dietary supplement on adjustment disorder with anxiety (Stress 2 study). Patients diagnosed as anxious with a score of ≥20 on the Hamilton Anxiety Rating Scale (Ham-A, first visit on Day 0 (V0)) were offered a 28-day treatment with a dietary supplement formulated with bioactive peptides from a fish protein hydrolysate (Gabolysat®), magnesium and vitamin B6. At the second visit (V1), the Ham-A Rating Scale, the Patient Global Impression scale (PGI) and the Clinical Global Impressions scale (CGI) were administered. A 50% reduction in the Ham-A score, was achieved for 41.9% of the patients. The mean Ham-A score decreased by 12.1 ± 5.7 points (p < 0.001) between V0 (25.6 ± 3.8) and V1 (13.6 ± 6.0). Furthermore, according to the CGI scale, the anxiety of 75.3% of patients improved significantly and very significantly, with limited side effects and a negligible rebound effect. In conclusion, adjustment disorder with anxiety seems to be effectively managed by an alternative and safer solution than benzodiazepines.

Bioactive peptides of whey: obtaining, activity, mechanism of action, and further applications

Bioactive peptides derived from diverse food proteins have been part of diverse investigations. Whey is a rich source of proteins and components related to biological activity. It is known that proteins have effects that promote health benefits. Peptides derived from whey proteins are currently widely studied. These bioactive peptides are amino acid sequences that are encrypted within the first structure of proteins, which required hydrolysis for their release. The hydrolysis could be through in vitro or in vivo enzymatic digestion and using microorganisms in fermented systems. The biological activities associated with bio-peptides include immunomodulatory properties, antibacterial, antihypertensive, antioxidant and opioid, etc. These functions are related to general conditions of health or reduced risk of certain chronic illnesses. To determine the suitability of these peptides/ingredients for applications in food technology, clinical studies are required to evaluate their bioavailability, health claims, and safety of them. This review aimed to describe the biological importance of whey proteins according to the incidence in human health, their role as bioactive peptides source, describing methods, and obtaining technics. In addition, the paper exposes biochemical mechanisms during the activity exerted by biopeptides of whey, and their application trends.

Investigating Differential Expressed Genes of Limosilactobacillus reuteri LR08 Regulated by Soybean Protein and Peptides

Soybean protein and peptides have the potential to promote the growth of Lactobacillus, but the mechanisms involved are not well understood. The purpose of this study is to investigate differentially expressed genes (DEGs) of Limosilactobacillus reuteri (L. reuteri) LR08 responding to soybean protein and peptides using transcriptome. The results showed that both digested protein (dpro) and digested peptides (dpep) could enhance a purine biosynthesis pathway which could provide more nucleic acid and ATP for bacteria growth. Moreover, dpep could be used instead of dpro to promote the ABC transporters, especially the genes involved in the transportation of various amino acids. Interestingly, dpro and dpep played opposite roles in modulating DEGs from the acc and fab gene families which participate in fatty acid biosynthesis. These not only provide a new direction for developing nitrogen-sourced prebiotics in the food industry but could also help us to understand the fundamental mechanism of the effects of dpro and dpep on their growth and metabolisms and provides relevant evidence for further investigation.