Dietary bioactive peptides: Human studies

pH-sensitive chitosan/sodium alginate/calcium chloride hydrogel beads for potential oral delivery of rice bran bioactive peptides

Although rice bran active peptide (RBAP) has potent antioxidant properties, its practical applications have been limited by its low bioavailability. In this study, we hypothesized that pH-responsive hydrogels prepared from the ionic gelation between chitosan and alginate could be a promising delivery system of short-chain peptides, like RBAP, for protecting them from chemical degradation during digestion and improving their functionality. The hydrogel beads retained RBAP in the gastric environment due to strong interactions between two biopolymers and RBAP, followed by a sustained release of more than 70 % peptide in the intestinal condition, thus improving its gastrointestinal stability. The RBAP-loaded hydrogel beads not only significantly enhanced free radical scavenging ability by 3-7 times during digestion but also protected human umbilical vein endothelial cells from H2O2-induced oxidative stress after digestion. This study presents a novel hydrogel platform for enhancing the gastrointestinal stability and functional efficacy of RBAP and other water-soluble peptides.

Ancient Latin-American food crops: An overview of their nutraceutical and antiobesity peptides

Most of the plants used for human consumption comprise various peptides with health benefits, such as antihypertensive, antioxidant, anti-inflammatory, anticancer, and immunomodulatory capacity. The intake of plant-based bioactive peptides is important in the prevention of some chronic diseases. Also, peptides show positive effects on lipid metabolism and mineral absorption and act as analgesic, antithrombotic, antiatherosclerotic, and opioid agents; it is pertinent to mention that peptides quite often exhibit multiple bioactivities. Bioactive peptides are released by the hydrolysis of digestive enzymes, that is, pepsin, chymotrypsin, trypsin, or by in vitro producers using specific enzymes, pH, and temperature. These peptides comprise hydrophobic amino acids, positive charge and are resistant to digestive hydrolysis by peptidases and proteases. Small peptides with a dipeptide of proline-proline at their C terminal are more resistant to gastrointestinal enzymes; otherwise, large peptides are active outside the intestinal epithelium. This review is focused on three selected ancient crops from Latin America, amaranth, chia, and quinoa, because of their outstanding nutritional and agronomic characteristics that provide a broad of functional compounds with high antioxidant, anti-inflammatory, immunomodulatory, antidiabetic, antihypertensive, anticancer, and antiobesity capacity.

Research Progress of Food-Derived Antihypertensive Peptides in Regulating the Key Factors of the Renin-Angiotensin System

Food protein-derived antihypertensive peptides have attracted substantial attention as a safer alternative for drugs. The regulation of the renin-angiotensin system (RAS) is an essential aspect underlying the mechanisms of antihypertensive peptides. Most of the identified antihypertensive peptides exhibit the angiotensin-converting enzyme (ACE) inhibitory effect. In addition, artificial intelligence has improved the efficiency of ACE inhibitory peptide identifications. Moreover, the inhibition of renin and blockade or down-regulation of angiotensin type I receptor (AT1R) have also been demonstrated to be effective intervention strategies. With the identification of the ACE2/Ang (1-7)/MasR axis, activation or up-regulation of angiotensin-converting enzyme 2 (ACE2) has also emerged as a new intervention pathway. This review summarizes the research progress of antihypertensive peptides in intervening with hypertension from the perspective of their properties, sources, and key factors. The objective of this review is to provide theoretical references for the development of antihypertensive peptides and the explorations of the molecular mechanisms.

Enzymatic hydrolysis of duck blood protein produces stable bioactive peptides: Pilot-scale production, identification, and stability during gastrointestinal and plasma digestion

This study addresses the valorization of duck blood, an underutilized protein-rich by-product from the poultry industry, into bioactive protein hydrolysates with antioxidant and ACE inhibitory properties. Raw and heat-treated duck blood were compared as substrates for enzymatic hydrolysis using Neutrase and Papain. Gel electrophoresis revealed that heat treatment reduced fibrinogen content, while FTIR analysis showed that heat treatment modified the protein structure, increasing β-sheet content from 21.13 % to 34.96 %. Heat-treated duck blood hydrolyzed by Neutrase exhibited superior hydrolysis (9.53 %) and protein recovery (60.28 %) compared to raw blood. Pilot-scale production (1000 L) enhanced hydrolysate yield and maintained bioactive properties. LC-MS/MS analysis identified five novel bioactive peptides derived from the hydrolysate's 4-h simulated gastrointestinal (GI) digestion, with WMHVR demonstrating the highest antioxidant and ACE inhibitory activities. Molecular docking simulations revealed that WMHVR competitively inhibits ACE by binding to the S1, S2, and S' pockets through van der Waals and hydrogen bonding interactions. The GI-hydrolysate and identified peptides maintained bioactivity during simulated GI and blood plasma digestion, with ACE inhibition increasing over time. This research transforms food industry waste into functional protein hydrolysates, offering applications in nutraceuticals and functional foods while promoting sustainable practices through waste protein valorization.

Absorption of food-derived peptides: Mechanisms, influencing factors, and enhancement strategies

Food-derived peptides (FPs) are bioactive molecules produced from dietary proteins through enzymatic hydrolysis or fermentation. These peptides exhibit various biological activities. However, their efficacy largely depends on bioavailability, the ability to cross absorption barriers, and reach target sites within the body. This review addresses key issues in FP absorption, including barriers, pathways, influencing factors, and strategies to enhance absorption. The biochemical and physical barriers to FP absorption include pH variations, enzymes, unstirred water layer, mucus layer, and intestinal epithelial cells. FPs enter the bloodstream via four main pathways: carrier-mediated transport, endocytosis, paracellular, and passive diffusion. The barrier-crossing efficiency depends on the structural properties and state of FPs and coexisting substances. Absorption efficiency can be significantly improved with permeability enhancers, nano-delivery systems, and chemical modifications. These insights provide a scientific basis and practical guidance for optimizing the bioactivity and health benefits of food-derived peptides.

Obstacles, research progress, and prospects of oral delivery of bioactive peptides: a comprehensive review

Bioactive peptides hold significant potential for enhancing human health, however, their limited oral bioavailability poses a substantial barrier to their widespread use in the food and pharmaceutical industries. This article reviews the key factors influencing the absorption efficiency of oral bioactive peptides, including issues related to bitter taste perception, challenges in gastrointestinal environmental stability, and limitations in transmembrane transport. Furthermore, it highlights the latest technologies, such as osmotic technology, chemical modification, and advanced delivery systems, and discusses their advantages in enhancing the stability of bioactive peptides and facilitating intestinal absorption. In addition, the application and challenges of common delivery systems such as liposomes, emulsions, polymer nanoparticles, and hydrogels in oral bioactive peptide delivery are also discussed. This paper aims to provide a theoretical foundation for scientific research and practical applications of oral delivery of bioactive peptides, thereby promoting the further development of bioactive peptides in the context of human health.

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.

Effect of food derived bioactive peptides on gut health and inflammatory mediators in vivo: a systematic review

Dietary proteins serve as sources of exogenous peptides, after being released from the protein and absorbed, the bioactive peptides can perform several functions in the body. The objective of the current systematic review is to answer the question "How does food derived bioactive peptides can impact on gut health and inflammatory mediators in vivo?" The search was performed at PubMed, Cochrane, and Scopus databases for experimental studies, and the risk of bias was assessed by the SYRCLE tool. The data analysis was conducted following the PRISMA guidelines. Eleven studies performed in animal models evaluating bioactive peptides derived from animal and plant sources were included and evaluated for limitations in heterogeneity, methodologies, absence of information regarding the allocation process, and investigators' blinding. The bioactive peptides demonstrated potential positive effects on inflammation and gut health. The main results identified were a reduction in TNF-α, NF-κB, and TLR4, an improvement in IgA production and in intestinal morphology, with an increase in villi surface area and goblet cell diameter, and Shannon and Simpson indexes were also increased. However, more in vivo studies are still necessary to better elucidate the anti-inflammatory activity and mechanisms by which peptides regulate gut health. PROSPERO (CRD42023416680).

Fermented foods and metabolic outcomes in diabetes and prediabetes: A systematic review and meta-analysis of randomized controlled trials

Several randomized controlled trials (RCTs) have investigated the effects of fermented foods on metabolic outcomes in adult patients suffering from diabetes and prediabetes. However, the results of these RCTs are conflicting. This systematic review and meta-analysis was carried out on data from RCTs to evaluate the effects of fermented foods in patients with diabetes and prediabetes. The PubMed, Web of Science, Embase, the Cochrane Library and Scopus databases were searched up to 21 June, 2022. English-language RCTs of fermented foods consumption were included which gave metabolic outcomes on body composition, glucose control, insulin sensitivity, lipid profile, as well as blood pressure. Eighteen RCTs met the inclusion criteria and 843 participants were included in the final analysis. The pooled results showed a significant reduction of fasting blood glucose (FBG), the homeostatic model assessment of insulin resistance (HOMA-IR), total cholesterol (TC), low density lipid cholesterol (LDL-C) and diastolic blood pressure (DBP) in the intervention group versus the control group. The results of this research showed that fermented foods have the potential to improve some metabolic outcomes, including FBG, HOMA-IR, TC, LDL-C, and DBP in patients with diabetes and prediabetes.

Advances in the application and mechanism of bioactive peptides in the treatment of inflammation

Inflammation is a normal immune response in organisms, but it often triggers chronic diseases such as colitis and arthritis. Currently, the most widely used anti-inflammatory drugs are non-steroidal anti-inflammatory drugs, albeit they are accompanied by various adverse effects such as hypertension and renal dysfunction. Bioactive peptides (BAPs) provide therapeutic benefits for inflammation and mitigate side effects. Herein, this review focuses on the therapeutic effects of various BAPs on inflammation in different body parts. Emphasis is placed on the immunomodulatory mechanisms of BAPs in treating inflammation, such as regulating the release of inflammatory mediators, modulating MAPK and NF-κB signaling pathways, and reducing oxidative stress reactions for immunomodulation. This review aims to provide a reference for the function, application, and anti-inflammation mechanisms of BAPs.

Gastrointestinal digestion of food proteins: Anticancer, antihypertensive, anti-obesity, and immunomodulatory mechanisms of the derived peptides

Food proteins and their peptides play a significant role in the important biological processes and physiological functions of the body. The peptides show diverse biological benefits ranging from anticancer to antihypertensive, anti-obesity, and immunomodulatory, among others. In this review, an overview of food protein digestion in the gastrointestinal tract and the mechanisms involved was presented. As some proteins remain resistant and undigested, the multifarious factors (e.g. protein type and structure, microbial composition, pH levels and redox potential, host factors, etc.) affecting their colonic fermentation, the derived peptides, and amino acids that evade intestinal digestion are thus considered. The section that follows focuses on the mechanisms of the peptides with anticancer, antihypertensive, anti-obesity, and immunomodulatory effects. As further considerations were made, it is concluded that clinical studies targeting a clear understanding of the gastrointestinal stability, bioavailability, and safety of food-based peptides are still warranted.

Therapeutic Benefits of Tuna Oil by In Vitro and In Vivo Studies Using a Rat Model of Acetic Acid-Induced Ulcerative Colitis

Ulcerative colitis (UC), an inflammation of the colon lining, represents the main form of inflammatory bowel disease IBD. Nutritional therapy is extremely important in the management of ulcerative colitis. Fish oil contains long-chain omega-3 polyunsaturated fatty acids, which have beneficial effects on health, including anti-inflammatory effects. This study aims to investigate the benefits of bluefin tuna oil extracted by the Soxhlet method in vitro by determining the anti-radical and anti-inflammatory activities and in vivo by evaluating the preventive and curative effects. The experiments were carried out using two doses of oil (100 and 260 mg/kg) and glutamine (400 and 1000 mg/kg) on the acetic acid-induced UC model. UC has been induced in Wistar rats by intrarectal administration of a single dose of 1 mL acetic acid (5% v/v in distilled water). The obtained results indicate that tuna oil and glutamine have a significant anti-free radical effect. Tuna oil has a marked anti-inflammatory power based on membrane stabilization and inhibiting protein denaturation. The reduction of various UC parameters, such as weight loss, disease activity score DAS, and colonic ulceration in rats pre-treated with tuna oil and glutamine, demonstrate that these treatments have a significant effect on UC. Total glutathione GSH, superoxide dismutase SOD, and catalase activities are significantly restored in the tuna oil and glutamine groups, while lipid peroxidation has been markedly reduced.

Effects of collagen hydrolysates on UV-induced photoaging mice: Gly-Pro-Hyp as a potent anti-photoaging peptide

This work aimed to investigate the protective effects of collagen hydrolysates containing different contents of Gly-Pro-Xaa tripeptides on UV-induced photoaging mice and to identify potent anti-photoaging peptides. Results showed that oral ingestion of collagen hydrolysates with a higher content of Gly-Pro-Xaa tripeptides (∼11.4%, HCH) dramatically enhanced the absorption of Pro-Hyp, Hyp-Gly, and Gly-Pro-Hyp into the body, which were 1.77-, 2.18-, and 65.07-fold higher in area under the concentration-time curve (AUC) values than that of collagen hydrolysates with a lower content of Gly-Pro-Xaa tripeptides (∼3.8%, LCH), respectively. Furthermore, the protective effects of HCH on the photo-aged skin of mice were significantly stronger than those of LCH in terms of increases in the contents of hyaluronic acid and collagen, improvement in skin elasticity and epidermal thickness, alleviation in inflammation, and decreases in the contents of matrix metalloproteinase-1 (MMP-1) and MMP-3. More importantly, Gly-Pro-Hyp displayed potent anti-photoaging activities comparable to HCH based on an equivalent amount of Hyp. Network pharmacology analysis for potential mechanisms further indicated that Gly-Pro-Hyp might interact with JUN and FOS and regulate IL-17 and TNF signaling pathways. Collectively, our results suggested that HCH had great potential to be applied in functional foods for skin health and Gly-Pro-Hyp was found to be a potent collagen-derived anti-photoaging peptide, which might contribute to the excellent anti-photoaging effects of HCH.

Antioxidant peptides generated from chicken feet protein hydrolysates

BACKGROUND

As major industrial poultry by-products, chicken feet are considered as notable sources of several bioactive molecules. The current work covers the processing of chicken feet proteins as substrates to be hydrolysed by combinations of three commercial enzymes (Alcalase®, Flavourzyme® and Protana® Prime) during different hydrolysis periods and the evaluation of the identified peptides having antioxidant activity after simulated gastrointestinal digestion.

RESULTS

Enzymatic hydrolysis with Alcalase® and Protana® Prime combination for 4 h resulted in the highest activities. Reversed-phase high-performance liquid chromatographic separation of the purified hydrolysate yielded three active fractions that were further identified by nano-liquid chromatography-tandem mass spectrometry. The bioactivities of over 230 identified peptide sequences were estimated after simulated gastrointestinal digestion, and those peptides with the highest chance of exerting antioxidant activity were selected to be further synthesised and tested. In this sense, the synthesised dipeptides CF and GY showed the highest antioxidant capacity. CF presented IC50 values of 69.63 and 145.41 μmol L-1 in 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and oxygen radical absorbance capacity (ORAC) assays, respectively. In contrast, GY IC50 values were 15.27 and 10.06 μmol L-1 in ABTS and ORAC assays, respectively. Significant differences (P < 0.05) were registered between peptides in the same antioxidant assays.

CONCLUSION

Overall, the findings emphasised the favourable impact of enzymatic hydrolysis with the obtaining of antioxidant peptides from poultry by-products that could be evaluated as a safe and economical source to retard oxidation in food systems. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Specific and nonspecific nutritional interventions enhance the development of oral tolerance in food allergy

The goal of food allergy (FA) prevention and treatment is to induce oral tolerance (OT). Appropriate nutritional interventions are essential to induce OT to food allergens. This review introduces the mechanism of OT and the importance of early nutritional interventions, and then firstly summarizes specific nutritional factors to induce the development of OT of FA, including proteins, vitamins, fatty acids, saccharides and probiotics. The regulatory mechanism mainly induces the development of tolerance by increasing local or systemic protective regulatory T cells (Tregs) to suppress FA, while the gut microbiota may also be changed to maintain intestinal homeostasis. For allergens-specific OT, the disruption to the structure of proteins and epitopes is critical for the induction of tolerance by hydrolyzed and heated proteins. Vitamins (vitamin A, D), fatty acids, saccharides and probiotics as allergens nonspecific OT also induce the development of OT through immunomodulatory effects. This review contributes to our understanding of OT in FA through nutritional interventions. Nutritional interventions play an important role in the induction of OT, and offer promising approaches to reduce allergy risk and alleviate FA. Moreover, due to the importance and diversity of nutrition, it must be the future trend of induction of OT in FA.

Walnut (Juglans regia L.) Oligopeptides Alleviate Alcohol-Induced Acute Liver Injury through the Inhibition of Inflammation and Oxidative Stress in Rats

The study was aimed at investigating the effects of walnut oligopeptides (WOPs) on alcohol-induced acute liver injury and its underlying mechanisms. Male Sprague Dawley (SD) rats were randomly assigned to six groups: normal control, alcohol control, whey protein (440 mg/kg.bw), and three WOPs (220 mg/kg.bw, 440 mg/kg.bw, 880 mg/kg.bw) groups. After 30 days of gavage, ethanol with a volume fraction of 50%, administered at a dose of 7 g/kg.bw., caused acute liver injury. A righting reflex experiment and a blood ethanol concentration evaluation were then performed. Serum biochemical parameters, inflammatory cytokines, liver alcohol metabolism enzymes, oxidative stress biomarkers, liver nuclear factor-κB (NF-κB p65), and cytochrome P4502E1 expression were determined. The results revealed that the intervention of 440 mg/kg and 880 mg/kg WOPs could alleviate the degree of intoxication, decrease blood ethanol concentration, alleviate alcohol-induced hepatic steatosis, enhance the activity of hepatic ethanol metabolizing enzymes and antioxidant capacity, reduce lipid oxidation products and pro-inflammatory factor contents, and inhibit the expression of NF-κBp65 in the livers of rats. The outcomes of the study suggest that WOPs have beneficial effects on liver damage caused by acute ethanol binge drinking, with the high-dose WOPs (880 mg/kg.bw) exerting the most pronounced hepatoprotective effect.

Critical features of an in vitro intestinal absorption model to study the first key aspects underlying food allergen sensitization

New types of protein sources will enter our diet in a near future, reinforcing the need for a straightforward in vitro (cell-based) screening model to test and predict the safety of these novel proteins, in particular their potential risk for de novo allergic sensitization. The Adverse Outcome Pathway (AOP) for allergen sensitization describes the current knowledge of key events underlying the complex cellular interactions that proceed allergic food sensitization. Currently, there is no consensus on the in vitro model to study the intestinal translocation of proteins as well as the epithelial activation, which comprise the first molecular initiation events (ME1-3) and the first key event of the AOP, respectively. As members of INFOGEST, we have highlighted several critical features that should be considered for any proposed in vitro model to study epithelial protein transport in the context of allergic sensitization. In addition, we defined which intestinal cell types are indispensable in a consensus model of the first steps of the AOP, and which cell types are optional or desired when there is the possibility to create a more complex cell model. A model of these first key aspects of the AOP can be used to study the gut epithelial translocation behavior of known hypo- and hyperallergens, juxtaposed to the transport behavior of novel proteins as a first screen for risk management of dietary proteins. Indeed, this disquisition forms a basis for the development of a future consensus model of the allergic sensitization cascade, comprising also the other key events (KE2-5).

A critical review on immunomodulatory peptides from plant sources; action mechanisms and recent advances

Plant protein components contribute positively to human well-being as they modulate the immune status of a consumer, especially when the enzymatic method is employed in order to release their bioactive peptides. These peptides are derived from plant-based foods such as soy, wheat, barley, rye, oats, rice, corn, sorghum, and millet, the famous staple foods around the world. Since these peptides are crucial to functional food among other key industries, the present study endeavored to scout for relevant information within the past three decades, using the Web of Science, Scopus, and Google search engines. In this review, first, the core of immunomodulation and types of immunomodulatory agents will be discussed, followed by the production of plant-based immunomodulatory peptides and their immunomodulatory mechanisms in cells, animals, and humans are also studied. Finally, applications and challenges associated with plant-based immunomodulatory peptides are put forward.

Bioactive and Sensory Di- and Tripeptides Generated during Dry-Curing of Pork Meat

Dry-cured pork products, such as dry-cured ham, undergo an extensive proteolysis during manufacturing process which determines the organoleptic properties of the final product. As a result of endogenous pork muscle endo- and exopeptidases, many medium- and short-chain peptides are released from muscle proteins. Many of them have been isolated, identified, and characterized, and some peptides have been reported to exert relevant bioactivity with potential benefit for human health. However, little attention has been given to di- and tripeptides, which are far less known, although they have received increasing attention in recent years due to their high potential relevance in terms of bioactivity and role in taste development. This review gathers the current knowledge about di- and tripeptides, regarding their bioactivity and sensory properties and focusing on their generation during long-term processing such as dry-cured pork meats.

The use of amino acid formulas in pediatric patients with allergy to cow's milk proteins: Recommendations from a group of experts

One of the most common food allergies in children is cow's milk allergy (CMA). In breast-fed infants with CMA, the mother is encouraged to avoid dairy products. If this is not possible, or in formula fed infants, use of hypoallergenic replacement formulas such as extensively hydrolyzed formulas (EHF) is recommended. However, in ∼5% of patients EHFs are not tolerated and/or allergy symptoms can persist. When EHFs are ineffective and in severe forms of CMA, amino acid-based formulas (AAF) should be considered. Six pediatric gastroenterologists with extensive experience in food allergy management reviewed scientific publications and international clinical practice guidelines to provide practical recommendations on AAF. The guidelines reviewed had discrepancies and ambiguities around the specific indications for using formulas as a milk substitute. The panel recommends AAFs as the first therapeutic option in anaphylaxis due to CMA, in acute and chronic severe food protein-induced enterocolitis syndrome, in CMA associated with multiple food allergy, and in cases of eosinophilic esophagitis not responding to an extended exclusion diet or not eating solids. The main benefit of AAF is its absence of residual allergenicity, making it a safe treatment option in severe CMA patients who do not tolerate or respond to an EHF.

Species Identification of Bovine Bone Marrow from Nonbovine Products Using Multiplex PCR Technology

Bovine bone marrow is traditionally regarded as a highly nutritious food that has been widely used as a medicinal and health food for several decades in China. A large number of adulterated and counterfeit bone marrows from pigs and donkeys have been used in place of bovine bone marrow in commercial products, which are almost identical morphologically between species. Therefore, we explored the feasibility of multiplex PCR technology to differentiate bovine bone marrows from different domestic animals. Three pairs of specific primers for bovine, pig, and donkey were designed according to the conserved sequence in mitochondrial cytochrome b. A modified method was used to extract the genomic DNA from common domestic animals’ bone marrows. The optimal reaction conditions for triple PCR were optimized. A three-fold PCR detection assay was successfully established to identify three species of bovine, pig, and donkey. Three primers have good specificity and high sensitivity. Additionally, the assay sensitivity test confirmed that the extracted DNA concentration was the lowest in bovine bone marrow at 10°pg/μL. The assay also showed 100% specificity. Rapid authentication of bovine bone marrow and differentiation from nonbovine products can be achieved using an improved SDS alkali denaturation method and species-specific PCR assay. Both species-specific PCR methods described in this study can be potentially applied for the quality evaluation of functional food and drug resources.

Tilapia skin peptides, a by-product of fish processing, ameliorate DSS-induced colitis by regulating inflammation and inhibiting apoptosis

Intestinal bowel disease (IBD) has always been tough to treat, therefore researchers are struggle to look for treatments that are safe, low cost, and effective. Food-derived peptides are thought to have anti-inflammatory and antioxidant properties, but they have not been studied in depth in the treatment of IBD. Based on this, we explored the effect of tilapia skin peptides (TSPs) on the remission of colitis in the present study. Colonic epithelial cell lines CT-26 and HT-29 were co-treated with lipopolysaccharide (LPS) and TSPs for 12 h. Cell viability was assessed by CCK8 assay. Dextran sulfate sodium (DSS)-induced colitis model was established and 100 mg/kg TSPs were oral administered at the same time as DSS intervention. Colonic mucosal barrier function was assessed by western blotting. The inflammatory responses were evaluated by quantitative real-time PCR along with ELISA, respectively. Apoptosis was investigated by TUNEL and flow cytometry. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to characterize peptides composition of TSPs. It was found that TSPs significantly inhibit LPS-induced inflammation and apoptosis in vitro without affecting cell viability. Moreover, the upregulation and activation of Caspase-3 and Caspase-8 were also reversed by TSPs. Subsequently, in vivo experiments demonstrated that TSPs can attenuate DSS induced colitis, manifested by a decrease in weight loss and colon shortening. The expression of ZO-1 and occluding were significantly increased, and the pro-inflammatory cytokines were down-regulated. Meanwhile, TSPs alleviated DSS-induced apoptosis and reduced the expressions of Caspase-3 and Caspase-8. Finally, we found that TSPs were composed of 51 short peptides, and 12 of them were predicted to have significant biological activity. Collectively, this study suggested that TSPs can alleviate colon damage caused by foreign stimuli via inhibiting inflammation and apoptosis which indicated that it has great potential value for the treatment of IBD.

Food protein-derived bioactive peptides for the management of nutrition related chronic diseases

Dietary intervention via modifications of dietary pattern or supplementations of naturally derived bioactive compounds has been considered as an efficient approach in management of nutrition related chronic diseases. Food protein-derived bioactive peptide is representative of natural compounds which show the potential to prevent or mitigate nutrition related chronic diseases. In the past decades, substantial research has been conducted concentrating on the characterization, bioavailability, and activity assessment of bioactive peptides. Although various activities of bioactive peptides have been reported, the activity testes of most peptides were only conducted in cells and animal models. Some clinical trials of bioactive peptides were also reported but only limited to antihypertensive peptides, antidiabetic peptides and peptides modulating blood lipid profile. Hereby, clinical evidence of bioactive peptides in management of nutrition-related chronic diseases is summarized in this chapter, which aims at providing implications for the clinical studies of bioactive peptides in the future.

Comprehensive Review of γ-Glutamyl Peptides (γ-GPs) and Their Effect on Inflammation Concerning Cardiovascular Health

γ-Glutamyl peptides (γ-GPs) are a group of peptides naturally found in various food sources. The unique γ-bond potentially enables them to resist gastrointestinal digestion and offers high stability in vivo with a longer half-life. In recent years, these peptides have caught researchers' attention due to their ability to impart kokumi taste and elicit various physiological functions via the allosteric activation of the calcium-sensing receptor (CaSR). This review discusses the various food sources of γ-glutamyl peptides, different synthesis modes, allosteric activation of CaSR for taste perception, and associated multiple biological functions they can exhibit, with a special emphasis on their role in modulating chronic inflammation concerning cardiovascular health.

Influence of 5-Week Snack Supplementation with the Addition of Gelatin Hydrolysates from Carp Skins on Pro-Oxidative and Antioxidant Balance Disturbances (TOS, TAS) in a Group of Athletes

The research objective was to assess the effects of 5-week snack supplementation with added enzymatic hydrolysates from carp skins on shifts in pro-oxidative and antioxidant balance among athletes. The study comprised 49 adults (experimental group (E)—17, placebo (P)—16, control (C)—16) practicing endurance disciplines. Selected somatic indices and maximal oxygen uptake/m (VO2max) were measured. Based on VO2max, an individual exercise intensity was selected with predominating eccentric contractions (60% VO2max). The conducted tests consisted of 2 series (1st—graded and eccentric, 2nd—eccentric). The experimental group consumed a snack with added gelatin hydrolysates from carp skins for 5 weeks in between the series, the placebo—a snack without added hydrolysates, and in the control—no supplementation was implemented. Blood samples were taken before, and 1, 24 and 48 h after completion of the eccentric test. TAS and TOC concentrations in the blood plasma were assessed. No significant changes in TOS/TOC and TAS/TAC concentrations were noted between the 1st and the 2nd test series, before or following the eccentric test in the control and placebo groups. In the measurements performed 1, 24 and 48 h after completion, the observed differences were highly significant (p < 0.001). After 5 weeks of snack consumption, an increase from medium to high antioxidant potential was observed for E. Differences between the 1st and the 2nd test series were of high statistical significance (p < 0.001). The demonstrated differences in pro-oxidative-antioxidant balance indices between successive series allow to confirm antioxidant effects and indicate possibilities for its implementation, not only in sports.

The acute effects of milk intake on calcium homeostasis and cardiovascular outcome: A randomized crossover trial in postmenopausal women

OBJECTIVE

The importance of calcium intake from dairy in regard to cardiovascular health has been investigated in several studies with discrepant results. Hence, we aim to investigate the immediate effects of milk intake on cardiovascular function.

DESIGN

A randomized crossover study with at least 10 days for washout between the two interventions, 500 ml of water with 200 µg of cholecalciferol or 500 ml of semi-skimmed milk containing approximately 600 mg of calcium with 200 µg of cholecalciferol.

PATIENTS

Twenty community-based postmenopausal women aged 60-80 years.

MEASUREMENTS

Parathyroid hormone and ionized calcium were measured at baseline and after 2 and 4 h on each study day. Pulse wave analysis and velocity were measured at baseline and after 4 h on each study day.

RESULTS

Compared to water, milk intake increased ionized calcium levels by 0.02 mmol/L (p = .029) and decreased parathyroid hormone levels by 1.78 pmol/L (p < .001). The two interventions caused no changes as measured 4 h after the intervention in the following indices of cardiovascular health; pulse wave velocity, brachial diastolic or systolic blood pressure, central diastolic or systolic blood pressure, mean arterial pressure, pulse pressure, augmentation pressure, augmentation index, heart rate or pulse transit time.

CONCLUSIONS

Despite significant changes in calcium homeostasis with increased levels of ionized calcium following milk intake, no acute effects seem to occur on measures of cardiovascular health.

Production, bioactivities and bioavailability of bioactive peptides derived from walnut origin by-products: a review

Walnut-origin by-products obtained from walnut oil extraction industry are high in proteins with various physiological functions and pharmacological properties and an extensive potential for usage in producing bioactive peptides. This review presents the current research status of bioactive peptides derived from walnut by-products, including preparation, separation, purification, identification, bioactivities, and bioavailability. A plethora of walnut peptides with multiple biological activities, including antioxidative, antihypertensive, neuroprotective, antidiabetic, anticancer, and antihyperuricemia activities, were obtained from walnut-origin by-products by enzymatic hydrolysis, fermentation, and synthesis. Different bioactive peptides show various structural characteristics and amino acid composition due to their diverse mechanism of action. Furthermore, walnut protein and its hydrolysate present a high bioavailability in human gastrointestinal digestive system. Improving the bioavailability of walnut peptides is needful in the development of walnut industry. However, future research still needs to exploit energy conservation, high efficiency, environmentally friendly and low-cost production method of walnut bioactive peptide. The molecular mechanisms of different bioactive walnut peptides still need to be explored at the cell and gene levels. Additionally, the digestion, absorption, and metabolism processes of walnut peptides are also the focus of future research.

Bioactivity of peptides obtained from poultry by-products: A review

The production and consumption of poultry products (chicken, duck, and turkey) are continually growing throughout the world, leading to the generation of thousands of tons of organic by-products, which may be important sources of bioactive peptides. The bioactive peptides isolated from poultry by-products have biological properties that can be useful in the prevention of different metabolic diseases and hence, their consumption could be beneficial for human health. Such peptides can be used as nutraceuticals, and their inclusion as active components of functional food products is increasingly gaining attention. The aim of this review was to present the investigations of the biological effect of the peptides obtained from different poultry by-products and the possible mechanisms of action underlying these effects.

An updated review on food-derived bioactive peptides: Focus on the regulatory requirements, safety, and bioavailability

Food-derived bioactive peptides (BAPs) are recently utilized as functional food raw materials owing to their potential health benefits. Although there is a huge amount of scientific research about BAPs' identification, purification, characterization, and physiological functions, and subsequently, many BAPs have been marketed, there is a paucity of review on the regulatory requirements, bioavailability, and safety of BAPs. Thus, this review focuses on the toxic peptides that could arise from their primary proteins throughout protein extraction, protein pretreatment, and BAPs' formulation. Also, the influences of BAPs' length and administration dosage on safety are summarized. Lastly, the challenges and possibilities in BAPs' bioavailability and regulatory requirements in different countries were also presented. Results revealed that the human studies of BAPs are essential for approvals as healthy food and to prevent the consumers from misinformation and false promises. The BAPs that escape the gastrointestinal tract epithelium and move to the stomach are considered good peptides and get circulated into the blood using different pathways. In addition, the hydrophobicity, net charge, molecular size, length, amino acids composition/sequences, and structural characteristics of BAPs are critical for bioavailability, and appropriate food-grade carriers can enhance it. The abovementioned features are also vital to optimize the solubility, water holding capacity, emulsifying ability, and foaming property of BAPs in food products. In the case of safety, the possible allergenic and toxic peptides often exhibit physiological functions and could be produced during the hydrolysis of food proteins. It was also noted that the production of iso-peptides bonds and undesirable Maillard reaction might occur during protein extraction, sample pretreatments, and peptide synthesis.

Ameliorative Effects of Peptides Derived from Oyster (Crassostrea gigas) on Immunomodulatory Function and Gut Microbiota Structure in Cyclophosphamide-Treated Mice

The intestinal flora is recognized as a significant contributor to the immune system. In this research, the protective effects of oyster peptides on immune regulation and intestinal microbiota were investigated in mice treated with cyclophosphamide. The results showed that oyster peptides restored the indexes of thymus, spleen and liver, stimulated cytokines secretion and promoted the relative mRNA levels of Th1/Th2 cytokines (IL-2, IFN-γ, IL-4 and IL-10). The mRNA levels of Occludin, Claudin-1, ZO-1, and Mucin-2 were up-regulated, and the NF-κB signaling pathway was also activated after oyster peptides administration. Furthermore, oyster peptides treatment reduced the proportion of Firmicutes/Bacteroidetes, increased the relative abundance of Alistipes, Lactobacillus, Rikenell and the content of short-chain fatty acids, and reversed the composition of intestinal microflora similar to that of normal mice. In conclusion, oyster peptides effectively ameliorated cyclophosphamide-induced intestinal damage and modified gut microbiota structure in mice, and might be utilized as a beneficial ingredient in functional foods for immune regulation.

Inhibition of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase enzyme by dipeptides identified in dry-cured ham

High cholesterolemia is a key risk factor for the development of cardiovascular diseases, which are the main cause of mortality in developed countries. Most therapies are focused on the modulation of its biosynthesis through 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMG-CoAR) inhibitors. In this sense, food-derived bioactive peptides might act as promising health alternatives through their ability to interact with crucial enzymes involved in metabolic pathways, avoiding the adverse effects of synthetic drugs. Dry-cured ham has been widely described as an important source of naturally-generated bioactive peptides exerting ACEI-inhibitory activity, antioxidant activity, and anti-inflammatory activity between others. Based on these findings, the aim of this work was to assess, for the first time, the in vitro inhibitory activity of HMG-CoAR exerted by dipeptides generated during the manufacturing of dry-cured ham, previously described with relevant roles on other bioactivities.

The in vitro inhibitory activity of the dipeptides was assessed by measuring the substrate consumption rate of the 3-hydroxy-3-methylglutaryl CoA reductase in their presence, with the following pertinent calculations.

Further research was carried out to estimate the possible interactions of the most bioactive dipeptides with the enzyme by performing in silico analysis consisting of molecular docking approaches.

Main findings showed DA, DD, EE, ES, and LL dipeptides as main HMG-CoAR inhibitors. Additionally, computational analysis indicated statin-like interactions of the dipeptides with HMG-CoAR.

This study reveals, for the first time, the hypocholesterolemic potential of dry-cured ham-derived dipeptides and, at the same time, converges in the same vein as many reports that experimentally argue the cardiovascular benefits of dry-cured ham consumption due to its bioactive peptide content.

Bioactive peptides from foods: production, function, and application

Bioactive peptides are a class of peptides with special physiological functions and have potential applications in human health and disease prevention. Bioactive peptides have gained much research attention because they affect the cardiovascular, endocrine, immune, and nervous systems. Recent research has reported that bioactive peptides are of great value for physiological function regulation, including antioxidation, anti-hypertension, antithrombosis, antibacterial properties, anti-cancer, anti-inflammation, anti-diabetic, anti-obesity, cholesterol-lowering, immunoregulation, mineral binding and opioid activities. The production of food-derived bioactive peptides is mainly through the hydrolysis of digestive enzymes and proteolytic enzymes or microbial fermentation. The purpose of this review is to introduce the production, function, application, challenges, and prospects of food-derived bioactive peptides.

Protective Effect of Tuna Bioactive Peptide on Dextran Sulfate Sodium-Induced Colitis in Mice

Bioactive peptides isolated from marine organisms have shown to have potential anti-inflammatory effects. This study aimed to investigate the intestinal protection effect of low molecular peptides (Mw < 1 kDa) produced through enzymatic hydrolysis of tuna processing waste (tuna bioactive peptides (TBP)) on dextran sulfate sodium (DSS)-induced ulcerative colitis (UC) in BALB/c mice. Here, we randomly divided twenty-four male BALB/c mice into four groups: (i) normal (untreated), (ii) DSS-induced model colitis, (iii) low dose TBP+DSS-treated (200 mg/kg/d), and (iv) high dose TBP+DSS-treated groups (500 mg/kg/d). The results showed that TBP significantly reduced mice weight loss and improved morphological and pathological characteristics of colon tissues. In addition, it increased the activities of antioxidant enzymes (SOD and GSH-Px) and decreased inflammatory factors (LPS, IL-6, and TNF-α) expression. TBP increased the gene expression levels of some tight junction (TJ) proteins. Moreover, TBP increased the short-chain fatty acids (SCFAs) levels and the diversity and imbalance of intestinal flora. Therefore, TBP plays some protective roles in the intestinal tract by enhancing antioxidant and anti-inflammatory abilities of the body, improving the intestinal barrier and metabolic abnormalities, and adjusting intestinal flora imbalance.

Bioactive peptides in the management of lifestyle-related diseases: Current trends and future perspectives

Lifestyle-related diseases constitute a major concern in the twenty-first century, with millions dying worldwide each year due to chosen lifestyles and associated complications such as obesity, type 2 diabetes, hypertension, and hypercholesterolemia. Although synthetic drugs have been shown to be quite effective in the treatment of these conditions, safety of these compounds remains a concern. Natural alternatives to drugs include food-derived peptides are now being explored for the prevention and treatment of lifestyle-related complications. Peptides are fragments nascent in the primary protein sequences and could impart health benefits beyond basic nutritional advantages. Evidence suggests that by controlling adipocyte differentiation and lipase activities, bioactive peptides may be able to prevent obesity. Bioactive peptides act as agents against type 2 diabetes because of their ability to inhibit enzymatic activities of DPP-IV, α-amylase, and α-glucosidase. Moreover, bioactive peptides can act as competitive inhibitors of angiotensin-converting enzyme, thus eliciting an antihypertensive effect. Bioactive peptides may have a hypocholesterolemic effect by inhibiting cholesterol metabolism pathways and cholesterol synthesis. This review addresses current knowledge of the impact of food-derived bioactive peptides on lifestyle diseases. In addition, future insights on the clinical trials, allergenicity, cytotoxicity, gastrointestinal stability, and regulatory approvals have also been considered.

A Global Review on Short Peptides: Frontiers and Perspectives

Peptides are fragments of proteins that carry out biological functions. They act as signaling entities via all domains of life and interfere with protein-protein interactions, which are indispensable in bio-processes. Short peptides include fundamental molecular information for a prelude to the symphony of life. They have aroused considerable interest due to their unique features and great promise in innovative bio-therapies. This work focusing on the current state-of-the-art short peptide-based therapeutical developments is the first global review written by researchers from all continents, as a celebration of 100 years of peptide therapeutics since the commencement of insulin therapy in the 1920s. Peptide "drugs" initially played only the role of hormone analogs to balance disorders. Nowadays, they achieve numerous biomedical tasks, can cross membranes, or reach intracellular targets. The role of peptides in bio-processes can hardly be mimicked by other chemical substances. The article is divided into independent sections, which are related to either the progress in short peptide-based theranostics or the problems posing challenge to bio-medicine. In particular, the SWOT analysis of short peptides, their relevance in therapies of diverse diseases, improvements in (bio)synthesis platforms, advanced nano-supramolecular technologies, aptamers, altered peptide ligands and in silico methodologies to overcome peptide limitations, modern smart bio-functional materials, vaccines, and drug/gene-targeted delivery systems are discussed.

Milk consumption and multiple health outcomes: umbrella review of systematic reviews and meta-analyses in humans

In order to recapitulate the best available evidence of milk consumption and multiple health-related outcomes, we performed an umbrella review of meta-analyses and systematic reviews in humans. Totally, 41 meta-analyses with 45 unique health outcomes were included. Milk consumption was more often related to benefits than harm to a sequence of health-related outcomes. Dose–response analyses indicated that an increment of 200 ml (approximately 1 cup) milk intake per day was associated with a lower risk of cardiovascular disease, stroke, hypertension, colorectal cancer, metabolic syndrome, obesity and osteoporosis. Beneficial associations were also found for type 2 diabetes mellitus and Alzheimer's disease. Conversely, milk intake might be associated with higher risk of prostate cancer, Parkinson’s disease, acne and Fe-deficiency anaemia in infancy. Potential allergy or lactose intolerance need for caution. Milk consumption does more good than harm for human health in this umbrella review. Our results support milk consumption as part of a healthy diet. More well-designed randomized controlled trials are warranted.

Egg White Cystatin – A Review

Hen eggs are widely used, not only for human consumption, but also as an important material in food production and in pharmaceutical and cosmetics industry. Cystatin is a biologically active component of egg white, mostly used as an inhibitor of papain-like cysteine proteases. It was isolated from chicken egg white and has later been used in the nomenclature of structurally and functionally related proteins. Cystatins from animals, including mouse, rat, dog, cow and chicken egg white have been isolated and recently used in foodstuffs and drug administration. Cystatin has found its place and use in medicine due to its antimicrobial, antiviral and insecticidal effects, for the prevention of cerebral hemorrhage and control of cancer cell metastasis.

In-silico screening of bioactive phytopeptides for novel anti-ageing therapeutics

A metabolic network of energy-sensing molecular pathways drives the biological ageing process. Regulating certain network elements can help decelerate the ageing process and ameliorate ageing associated disorders. Bioactive phytopeptides are a prospective avenue for anti-ageing therapeutics and rejuvenation biotechnology. The present study investigates the potential of therapeutic plant peptides against cellular senescence by targeting three key proteins in the ageing network - target of rapamycin (mTOR), adenosine monophosphate-activated protein kinase (AMPK) and sirtuin 1 (SIRT1). This investigation screened a library of reported bioactive peptides using standard cheminformatic methods including in-silico ADMET, molecular docking, molecular dynamics simulation and molecular mechanics calculation. The retrieved simulation data predict 25 diverse phytopeptides as potential safe and drug-like anti-ageing biologics with half-lives >20 h and bioavailability scores >0.40. The best docked peptide, Cycloleonuripeptide B, exhibited strong binding affinity and stable complex formation with mTOR (-17.5 kCal/mol), SIRT1 (-28.54 kCal/mol) and two active sites in AMPK (-41.8 kCal/mol; -36.0 kCal/mol) during molecular dynamics simulations. The computational study acts as a foundation for future laboratory and clinical research into the potential of repurposing therapeutic phytopeptides against cellular senescence and associated pathophysiology. Communicated by Ramaswamy H. Sarma.

Food-Derived Opioid Peptides in Human Health: A Review

World Health Organization data suggest that stress, depression, and anxiety have a noticeable prevalence and are becoming some of the most common causes of disability in the Western world. Stress-related disorders are considered to be a challenge for the healthcare system with their great economic and social impact. The knowledge on these conditions is not very clear among many people, as a high proportion of patients do not respond to the currently available medications for targeting the monoaminergic system. In addition, the use of clinical drugs is also associated with various side effects such as vomiting, dizziness, sedation, nausea, constipation, and many more, which prevents their effective use. Therefore, opioid peptides derived from food sources are becoming one of the safe and natural alternatives because of their production from natural sources such as animals and plant proteins. The requirement for screening and considering dietary proteins as a source of bioactive peptides is highlighted to understand their potential roles in stress-related disorders as a part of a diet or as a drug complementing therapeutic prescription. In this review, we discussed current knowledge on opioid endogenous and exogenous peptides concentrating on their production, purification, and related studies. To fully understand their potential in stress-related conditions, either as a drug or as a therapeutic part of a diet prescription, the need to screen more dietary proteins as a source of novel opioid peptides is emphasized.

Current Evidence on the Bioavailability of Food Bioactive Peptides

Food protein-derived bioactive peptides are recognized as valuable ingredients of functional foods and/or nutraceuticals to promote health and reduce the risk of chronic diseases. However, although peptides have been demonstrated to exert multiple benefits by biochemical assays, cell culture, and animal models, the ability to translate the new findings into practical or commercial uses remains delayed. This fact is mainly due to the lack of correlation of in vitro findings with in vivo functions of peptides because of their low bioavailability. Once ingested, peptides need to resist the action of digestive enzymes during their transit through the gastrointestinal tract and cross the intestinal epithelial barrier to reach the target organs in an intact and active form to exert their health-promoting properties. Thus, for a better understanding of the in vivo physiological effects of food bioactive peptides, extensive research studies on their gastrointestinal stability and transport are needed. This review summarizes the most current evidence on those factors affecting the digestive and absorptive processes of food bioactive peptides, the recently designed models mimicking the gastrointestinal environment, as well as the novel strategies developed and currently applied to enhance the absorption and bioavailability of peptides.

The Coconut Water Antimicrobial Peptide CnAMP1 Is Taken up into Intestinal Cells but Does Not Alter P-Glycoprotein Expression and Activity

Coconut antimicrobial peptide-1 (CnAMP1) is a naturally occurring bioactive peptide from green coconut water (Cocos nucifera L.). Although biological activities have been reported, the physiological relevance of these reports remains elusive as it is unknown if CnAMP1 is taken up into intestinal cells. To address this open question, we investigated the cytotoxicity of CnAMP1 in intestinal cells and its cellular uptake into human intestinal cells. Considering the importance of the P-glycoprotein (P-gp) to the intestinal metabolism of xenobiotics, we also investigated the influence of CnAMP1 on P-gp activity and expression. Both cell lines showed intracellular fluorescence after incubation with fluorescein labelled CnAMP1, indicating cellular uptake of the intact or fragmented peptide. CnAMP1 (12.5-400 μmol/L) showed no signs of cytotoxicity in LS180 and differentiated Caco-2 cells and did not affect P-gp expression and activity. Further research is required to investigate the identity of CnAMP1 hydrolysis fragments and their potential biological activities.

Protein Recovery from Underutilised Marine Bioresources for Product Development with Nutraceutical and Pharmaceutical Bioactivities

The global demand for dietary proteins and protein-derived products are projected to dramatically increase which cannot be met using traditional protein sources. Seafood processing by-products (SPBs) and microalgae are promising resources that can fill the demand gap for proteins and protein derivatives. Globally, 32 million tonnes of SPBs are estimated to be produced annually which represents an inexpensive resource for protein recovery while technical advantages in microalgal biomass production would yield secure protein supplies with minimal competition for arable land and freshwater resources. Moreover, these biomaterials are a rich source of proteins with high nutritional quality while protein hydrolysates and biopeptides derived from these marine proteins possess several useful bioactivities for commercial applications in multiple industries. Efficient utilisation of these marine biomaterials for protein recovery would not only supplement global demand and save natural bioresources but would also successfully address the financial and environmental burdens of biowaste, paving the way for greener production and a circular economy. This comprehensive review analyses the potential of using SPBs and microalgae for protein recovery and production critically assessing the feasibility of current and emerging technologies used for the process development. Nutritional quality, functionalities, and bioactivities of the extracted proteins and derived products together with their potential applications for commercial product development are also systematically summarised and discussed.