Generation of bioactive peptide hydrolysates from cattle plasma using plant and fungal proteases

Novel anti-oxidative peptides from equine hemoplasma protein hydrolysates: Purification, identification and protective effects on Caco-2 cells

In this study, we purified and identified antioxidant peptides from equine plasma protein hydrolysates and assessed their protective effects against H2O2-induced oxidative stress in Caco-2 cells. Four antioxidant peptides were identified by liquid chromatography-tandem mass spectrometry (LC-MS/MS) in equine plasma protein hydrolysate, namely: GTMVGC (567.69 Da), FGMTST (662.88 Da), VGYHSHF (847.01 Da) and ALSPFFKE (939.18 Da). Among them, ALSPFFKE showed the strongest antidigestive properties after modelled digestion studies. Moreover, ALSPFFKE enhanced intracellular superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) activities while significantly reducing reactive oxygen species accumulation and malondialdehyde formation in Caco-2 cells. The molecular docking analysis suggested that ALSPFFKE achieves regulation of the Keap1-Nrf2 pathway mainly by forming multiple hydrogen bonds and hydrophobic interactions with key amino acids (Arg380, Ser555, Gln530, Tyr334) in Keap1. These findings suggested that equine plasma peptides hold significant promise for the development of novel, potent, and stable antioxidant functional foods.

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.

Assessment of functional efficacy of sheep plasma protein hydrolysates and their utilization in mutton sausage

The present study examines the bioactive potential of sheep plasma protein hydrolysates (SPPH) produced by in-vitro gastrointestinal digestion as antioxidants, antimicrobials, anti-obesity agents, and inhibitors of lipid oxidation in sausage to address the oxidative stability and shelf-life issues of mutton. The antioxidant and antimicrobial activities, indicate a positive relationship between the degree of hydrolysis and digestion duration. The study finds that SPPH has a potent inhibitory effect on pancreatic lipase and cholesterol esterase. It has higher oil holding capacity than sheep plasma protein, observed at one hour of hydrolysis time. SPPH exhibit an improved behavior in foaming properties along alkaline pH and digestion time while display lower emulsifying activity and stability with hydrolysis advancement. The SPPH act as a natural preservative in developing functional mutton sausage by inhibiting lipid-oxidation. This study showed that the recovery of SPPH can be a cost-effective and sustainable strategy for generating available ingredients for enhanced shelf-life of meat products.

Novel antioxidant peptides from sheep plasma protein hydrolysates: Purification, identification and cytoprotective effects against H2O2-induced oxidative stress

This study sought to purify and identify antioxidant peptides from sheep (Ovis aries) plasma protein hydrolysates and assess their protective impacts on H2O2-induced Caco-2 cells. The purification process involved reversed high-performance liquid chromatography, anion-exchange chromatography, and Sephadex G-25. Three peptides, namely Trp-Glu-Glu-Pro-Ala-Met (WEEPAM), Ser-Leu-His-Phe-Met-Glu (SLHFME), and His-Cys-Thr-Thr-Phe-Met-Ile, with molecular weights of 761.84, 762.87, and 852.03 Da, respectively, were identified by liquid chromatography with tandem mass spectrometry. Among the three antioxidant peptides, superoxide radical (O2 -) radical scavenging capacity of WEEPAM and SLHFME was not significantly different from glutathione (GSH) (p > 0.05), while their 1,1-diphenyl-2-picrylhydrazyl radical scavenging capacity was greater than GSH (p < 0.05). WEEPAM revealed increased antioxidant activity after pepsin and trypsin hydrolysis under an in vitro digestion model. In addition, WEEPAM inhibited oxidative damage in Caco-2 cells by significantly reducing reactive oxygen species accumulation, early apoptosis, malondialdehyde formation, and increasing intracellular superoxide dismutase, glutathione peroxidase, and catalase activities.

Current Insights in Fungal Importance-A Comprehensive Review

Besides plants and animals, the Fungi kingdom describes several species characterized by various forms and applications. They can be found in all habitats and play an essential role in the excellent functioning of the ecosystem, for example, as decomposers of plant material for the cycling of carbon and nutrients or as symbionts of plants. Furthermore, fungi have been used in many sectors for centuries, from producing food, beverages, and medications. Recently, they have gained significant recognition for protecting the environment, agriculture, and several industrial applications. The current article intends to review the beneficial roles of fungi used for a vast range of applications, such as the production of several enzymes and pigments, applications regarding food and pharmaceutical industries, the environment, and research domains, as well as the negative impacts of fungi (secondary metabolites production, etiological agents of diseases in plants, animals, and humans, as well as deteriogenic agents).

Comparison of Functional Properties of Blood Plasma Collected from Black Goat and Hanwoo Cattle

Slaughterhouse blood is a by-product of animal slaughter that can be a good source of animal protein. This research purposed to examine the functional qualities of the blood plasma from Hanwoo cattle, black goat, and their hydrolysates. Part of the plasma was hydrolyzed with proteolytic enzymes (Bacillus protease, papain, thermolysin, elastase, and α-chymotrypsin) to yield bioactive peptides under optimum conditions. The levels of hydrolysates were evaluated by 15% sodium dodecyl sulfate polyacrylamide gel electrophoresis. The antioxidant, metal-chelating, and angiotensin I-converting enzyme (ACE) inhibitory properties of intact blood plasma and selected hydrolysates were investigated. Accordingly, two plasma hydrolysates by protease (pH 6.5/55°C/3 h) and thermolysin (pH 7.5/37°C/3-6 h) were selected for analysis of their functional properties. In the oil model system, only goat blood plasma had lower levels of thiobarbituric acid reactive substances than the control. The diphenyl picrylhydrazyl radical scavenging activity was higher in cattle and goat plasma than in proteolytic hydrolysates. Ironchelating activities increased after proteolytic degradation except for protease-treated cattle blood. Copper-chelating activity was excellent in all test samples except for the original bovine plasma. As for ACE inhibition, only non-hydrolyzed goat plasma and its hydrolysates by thermolysin showed ACE inhibitory activity (9.86±5.03% and 21.77±3.74%). In conclusion, goat plasma without hydrolyzation and its hydrolysates can be a good source of bioactive compounds with functional characteristics, whereas cattle plasma has a relatively low value. Further studies on the molecular structure of these compounds are needed with more suitable enzyme combinations.

Artificial Intelligence in Functional Food Ingredient Discovery and Characterisation: A Focus on Bioactive Plant and Food Peptides

Scientific research consistently demonstrates that diseases may be delayed, treated, or even prevented and, thereby, health may be maintained with health-promoting functional food ingredients (FFIs). Consumers are increasingly demanding sound information about food, nutrition, nutrients, and their associated health benefits. Consequently, a nutrition industry is being formed around natural foods and FFIs, the economic growth of which is increasingly driven by consumer decisions. Information technology, in particular artificial intelligence (AI), is primed to vastly expand the pool of characterised and annotated FFIs available to consumers, by systematically discovering and characterising natural, efficacious, and safe bioactive ingredients (bioactives) that address specific health needs. However, FFI-producing companies are lagging in adopting AI technology for their ingredient development pipelines for several reasons, resulting in a lack of efficient means for large-scale and high-throughput molecular and functional ingredient characterisation. The arrival of the AI-led technological revolution allows for the comprehensive characterisation and understanding of the universe of FFI molecules, enabling the mining of the food and natural product space in an unprecedented manner. In turn, this expansion of bioactives dramatically increases the repertoire of FFIs available to the consumer, ultimately resulting in bioactives being specifically developed to target unmet health needs.

Impact of dietary porcine blood by-products in meagre (Argyrosomus regius) physiology, evaluated by welfare biomarkers and the antibacterial properties of the skin mucus

Tools are required for quick and easy preliminary evaluation of functional feeds efficiency on fisheries. The analysis of skin mucus biomarkers is a recent alternative approach providing a faster feed-back from the laboratory which is characterized by being less invasive, more rapid and with reduced costs. The effect of replacing fishmeal and fish protein hydrolysates by means of two porcine by-products, the porcine spray-dried plasma (SDPP) and pig protein hydrolysate (PPH), in compound diets (50.4% crude protein, 16.2% crude protein, 22.1 MJ/kg feed) was evaluated in juvenile meagre (Argyrosomus regius) during a two-months period. To determine the impact of these dietary replacements, growth and food performance were measured together with digestive enzymes activities and filet proximal composition. Additionally, skin mucus was collected and characterized by determining main mucus biomarkers (protein, glucose, lactate, cortisol, and antioxidant capacity) and its antibacterial properties, measured by the quick in vitro co-culture challenges. In comparison to the control group, the inclusion of PPH and SDPP, in meagre diets reduced growth (7.4-8.8% in body weight), increased feed conversion ratios (9.0-10.0%), results that were attributed to a reduction in feed intake values (24.2-33.0%) (P < 0.05). Porcine blood by-products did not modify the activity of gastric and pancreatic digestive enzymes as well as those involved in nutrient absorption (alkaline phosphatase) nor liver oxidative stress condition (P > 0.05). In contrast, a reduction in fillet lipid content associated to an increase in fillet protein levels were found in fish fed SDPP and PPH diets (P < 0.05). As compared to the control diet, the dietary replacement did not alter the levels of the skin mucus biomarkers related to stress (cortisol and antioxidant capacity) or nutritional status (soluble protein, glucose and lactate) (P > 0.05). Interestingly, regardless of the worst performance in somatic growth, meagre fed diets containing both tested porcine by-products showed a significantly improved antibacterial capacity of their skin mucus. This enhancement was more prominent for fish fed with the PPH diet, which may be attributed to a higher content of immunomodulatory bioactive compounds in PPH. Further research will be necessary to provide insights on how the inclusion of SDPP and PPH, at the expense of dietary fishmeal and fish protein hydrolysates, affects feed intake and growth performance in meagre. However, the use of skin mucus biomarkers has been demonstrated to be an excellent methodology for a preliminary characterization of the functional feeds, in particular for their prophylactic properties by the study of mucus antibacterial activity.

Purification and identification of antioxidant peptides from duck plasma proteins

The antioxidant peptides extracted from duck plasma hydrolysate (DPH) was investigated. The antioxidant activity of DPH, which was isolated and purified via ultrafiltration, size exclusion chromatography, and reversed-phase high-performance liquid chromatography, was evaluated using its free radical scavenging ability. Nano-liquid chromatography-tandem mass spectrometry was conducted to identify the DPH fractions with the highest antioxidant ability. Seven novel peptides: LDGP, TGVGTK, EVGK, RCLQ, LHDVK, KLGA, and AGGVPAG (400.43, 561.63, 431.48, 260.14, 610.71, 387.47, and 527.57 Da, respectively) were identified and synthesized using a solid-phase peptide produce to evaluate their antioxidant activities. Of these, EVGK exhibited the highest Fe²⁺ chelating ability (16.35%), and RCLQ presented the highest reducing power, 2,2-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt scavenging activity, and 1,1-diphenyl-2-picrylhydrazyl scavenging rate (0.62, 274.83 mM TE/mg, and 95.12%, respectively). Our results indicated that DPH possessed antioxidant capabilities and could be used to obtain antioxidant peptides, thus adding economic value to duck blood.

A comprehensive review of bioactive peptides obtained from animal byproducts and their applications

Livestock generates high quantities of residues, which has become a major socioeconomic issue for the meat industry. This review focuses on the identification of bioactive peptides (BPs) in animal byproducts and meat wastes. Firstly, the main bioactivities that peptides can have will be described and the methods for their evaluation will be discussed. Secondly, the various origins of these BPs will be studied. Then, the techniques and tools for the generation of BPs will be detailed in order to discuss, in the final part, how peptides could be used and assimilated. BPs possess diverse biological activities and can be strategic candidates for substituting synthetic molecules. In silico potentiality studies are a helpful tool to understand and predict BPs released from proteins and their potential activities. However, in vitro validation is often required. Although BP use is compelled by strict regulations in relation to the field of application, they are also limited by their low bioavailability and bioaccessibility. Therefore, it is important to test peptide stability during gastrointestinal digestion. Protective strategies have been discussed since their use could improve the stability and effectiveness of BPs.

Workflow towards the generation of bioactive hydrolysates from porcine products by combining in silico and in vitro approaches

Food-derived bioactive peptides have generated an increasing interest in the field of health and well-being research. They can act either against the metabolic syndrome, participate in regulating the oxidation balance or act on the immune system. The aim of this study is to develop a workflow to generate bioactive peptides from three porcine offals namely, heart, liver, and lung and one muscle the Longissimus Dorsi, by combining in silico and in vitro approaches. Bioinformatics tools (e.i. BIOPEP and Uniprot) permitted to orientate the choice of enzymes for generating abundant bioactive peptides from the four studied porcine products. With papain and subtilisin, the main bioactivities potentially released were ACE inhibitors, DPP4 inhibitors and antioxidant peptides. An in vitro validation study using papain and subtilisin demonstrated high DPP4 inhibitors and antioxidant bioactivities for the generation of peptides. This work allowed: i) the identification of all proteins that composed porcine heart, liver, lung and LD muscle that could be useful for the scientific community, ii) the development of a workflow to select most abundant proteins in a product while considering abundance factors and iii) the potential of porcine meat and offals to generate DPP4 inhibitors and antioxidant peptides. However, there is still a need in developing new tools in order to face limitations of mass spectrometry for the identification of peptides with less than six amino acids. Such a work may contribute to the development of the circular economy and the innovative creation of value-added products from animal production.

Purification and Identification of Antioxidant Alcalase-Derived Peptides from Sheep Plasma Proteins

In this study, sheep plasma was submitted to Alcalase-hydrolysis and peptides with better antioxidant properties measured through both the ferric-reducing antioxidant power (FRAP) and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging ability assays were isolated and identified. After hydrolysate ultrafiltration and semi-preparative reverse-phase high-performance liquid chromatography, nine fractions (F1-F9) were obtained, with the two first (F1 and F2) showing the greatest antioxidant potential. These two fractions were further separated by the AKTA purifier system to generate four (F1-1-F1-4) and five (F2-1-F2-5) fractions, respectively, with two of them (F1-2 and F2-1) exhibiting appreciable FRAP activity and DPPH radical scavenging ability. Using liquid chromatography-tandem mass spectrometry, three antioxidant peptides were identified. From their amino acid sequences (QTALVELLK, SLHTLFGDELCK, and MPCTEDYLSLILNR), which include amino acids that have been previously reported as key contributors to the peptide antioxidant properties, it can be maintained that they come mainly from serum albumin. These results suggested that the sheep plasma protein can be considered as a good source of antioxidant peptides and bring forth new possibilities for the utilization of animal blood by-products.

Separation and Enrichment of Antioxidant Peptides from Whey Protein Isolate Hydrolysate by Aqueous Two-Phase Extraction and Aqueous Two-Phase Flotation

At present, peptides are separated by molecular exclusion chromatography and liquid chromatography. A separation method is needed in any case, which can be scaled up for industrial scale. In this study, aqueous two-phase extraction (ATPE) and aqueous two-phase flotation (ATPF) were applied to separate and enrich antioxidant peptides from trypsin hydrolysates of whey protein isolates (WPI). The best experimental conditions were investigated, and the results were evaluated using the 2,2′-Azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free radical scavenging activity of the peptides-per-unit concentration and the recovery rate (Y) of peptides in the top phase of both ATPE and ATPF. Under optimal conditions, the Y and ABTS free radical scavenging activity per unit concentration in top phase of ATPE could reach 38.75% and 12.94%, respectively, and in ATPF could reach 11.71% and 29.18%, respectively. The purified peptides were characterized by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and reversed-phase high-performance liquid chromatography (RP-HPLC). PeptideCutter and PeptideMass were applied to analyze and calculate the peptide sequencing. KILDKVGINYWLAHK, VGINYWLAHKALCSEK, and TPEVDDEALEKFDKALK sequences having antioxidant activity were detected in the top phase of ATPE, and VGINYWLAHKALCSEK, KILLDKVGINYWLAHK, ILLDKVGINYWLAHK, IIAEKTKIPAVFK, KIIAEKTKIPAVFK, and VYVEELKPTPEGDLEILLQK sequences having antioxidant activity were detected in the top phase of ATPF. In conclusion, antioxidant peptides were successfully separated from the WPI hydrolysate by ATPE and ATPF; compared with ATPE, ATPF has superior specificity in separating antioxidant peptides.

Separation of Antioxidant Peptides from Pepsin Hydrolysate of Whey Protein Isolate by ATPS of EOPO Co-polymer (UCON)/Phosphate

An aqueous two-phase system (ATPS) consisting of poly(ethylene glycol-ran-propylene glycol) monobutyl ether (UCON)/phosphate was developed for the separation of the antioxidant peptides from pepsin hydrolysate of Whey Protein Isolate (WPI). The efficiency of the separation was evaluated based on the DPPH radical scavenging activity, ABTS radical scavenging activity and ferric reducing antioxidant power (FRAP) of the separated peptides. The effects of some parameters on the partition of antioxidant peptides were investigated. An efficient separation of antioxidant peptides was achieved using ATPS with pH of 4.0, 4 mL of UCON solution (40%, w/w), 4 mL of KH₂PO₄ solution (15.5%, w/w), 2 mL of WPI hydrolysate and 0.40 g/10 mL of NaCl. Reversed-phase high-performance liquid chromatography (RP-HPLC), amino acid analyzer and matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to characterize the purified peptides separated by the ATPS. The peptides in top phase were less polar than those in bottom phase. More antioxidative and hydrophobic amino acids were extracted to the top phase of ATPS, and the peptides with the amino acid sequences with antioxidant activities moved to the top phase as well. In conclusion, antioxidant peptides were successfully separated from the WPI hydrolysate by UCON/phosphate ATPS.

Effect of High-Pressure Treatment on Catalytic and Physicochemical Properties of Pepsin

For a long time, high-pressure treatment has been used to destroy the compact structures of natural proteins in order to promote subsequent enzymatic hydrolysis. However, there are few reports evaluating the feasibility of directly improving the catalytic capability of proteases by using high-pressure treatments. In this study, the effects of high-pressure treatment on the catalytic capacity and structure of pepsin were investigated, and the relationship between its catalytic properties and changes in its physicochemical properties was explored. It was found that high-pressure treatment could lead to changes of the sulfhydryl group/disulfide bond content, hydrophobicity, hydrodynamic radius, intrinsic viscosity, and subunit composition of pepsin, and the conformational change of pepsin resulted in improvement to its enzymatic activity and hydrolysis efficiency, which had an obvious relationship with the high-pressure treatment conditions.

Protein hydrolysates in animal nutrition: Industrial production, bioactive peptides, and functional significance

Recent years have witnessed growing interest in the role of peptides in animal nutrition. Chemical, enzymatic, or microbial hydrolysis of proteins in animal by-products or plant-source feedstuffs before feeding is an attractive means of generating high-quality small or large peptides that have both nutritional and physiological or regulatory functions in livestock, poultry and fish. These peptides may also be formed from ingested proteins in the gastrointestinal tract, but the types of resultant peptides can vary greatly with the physiological conditions of the animals and the composition of the diets. In the small intestine, large peptides are hydrolyzed to small peptides, which are absorbed into enterocytes faster than free amino acids (AAs) to provide a more balanced pattern of AAs in the blood circulation. Some peptides of plant or animal sources also have antimicrobial, antioxidant, antihypertensive, and immunomodulatory activities. Those peptides which confer biological functions beyond their nutritional value are called bioactive peptides. They are usually 2-20 AA residues in length but may consist of >20 AA residues. Inclusion of some (e.g. 2-8%) animal-protein hydrolysates (e.g., porcine intestine, porcine mucosa, salmon viscera, or poultry tissue hydrolysates) or soybean protein hydrolysates in practical corn- and soybean meal-based diets can ensure desirable rates of growth performance and feed efficiency in weanling pigs, young calves, post-hatching poultry, and fish. Thus, protein hydrolysates hold promise in optimizing the nutrition of domestic and companion animals, as well as their health (particularly gut health) and well-being.