Peptidomic analysis of bioactive peptides in zebra blenny (Salaria basilisca) muscle protein hydrolysate exhibiting antimicrobial activity obtained by fermentation with Bacillus mojavensis A21

Peptidomics- inspired discovery and activity evaluation of antioxidant peptides in multiple strains mixed fermentation of Porphyra yezoensis

This study investigated the production of antioxidant peptides from Porphyra yezoensis through fermentation with three strains of microorganisms: Lactiplantibacillus plantarum L13, Bacillus amyloliquefaciens MMB-02, and Saccharomyces cerevisiae A8. The crude peptides were extracted by aqueous acid precipitation and purified by Sephadex G-25 gel column to produce highly active antioxidant components with molecular weight of <4000 Da. The LC-MS/MS result revealed that the fermentation group contained more hydrophobic amino acids and oligopeptides, which were mainly originated from phycobiliproteins and algal blue proteins. Finally, the antioxidant activity of Porphyra yezoensis was determined with DPPH· and ABTS· scavenging rates of 54.87% and 57.39%, respectively. The ferric ion-reducing power (FRAP) and enzyme activities of SOD and CAT were significantly higher than those of the control group. This study provides a scientific foundation for the deep processing of striped seaweed and contributes to the theoretical understanding of synthetic antioxidant substitutes.

Bioactive protein hydrolysates obtained from amaranth by fermentation with lactic acid bacteria and Bacillus species

Protein hydrolysates are a promising source of bioactive peptides. One strategy by which they can be obtained is fermentation. This method uses the proteolytic system of microorganisms to hydrolyze the parental protein. Fermentation is a little-explored method for obtaining protein hydrolysates from amaranth. Different strains of lactic acid bacteria (LAB) and Bacillus species isolated from goat milk, broccoli, aguamiel, and amaranth flour were used in this work. First, the total protein degradation (%TPD) of amaranth demonstrated by the strains was determined. The results ranged from 0 to 95.95%, the strains that produced a higher %TPD were selected. These strains were identified by molecular biology and were found to correspond to the genera Enterococcus, Lactobacillus, Bacillus, and Leuconostoc. Fermentation was carried out with amaranth flour and the selected strains. After this process, water/salt extracts (WSE) containing the released protein hydrolysates were obtained from amaranth doughs. The peptide concentration was measured by the OPA method. The antioxidant, antihypertensive and antimicrobial activity of the WSE was evaluated. In the FRAP test, the best WSE was LR9 with a concentration of 1.99 μMTE/L ± 0.07. In ABTS, 18C6 obtained the highest concentration with 19.18 μMTE/L ± 0.96. In the DPPH test, there was no significant difference. In terms of antihypertensive activity, inhibition percentages ranging from 0 to 80.65% were obtained. Some WSE were found to have antimicrobial properties against Salmonella enterica and Listeria monocytogenes. Fermentation of amaranth with LAB and Bacillus spp. allowed the release of protein hydrolysates with antioxidant, antihypertensive, and antimicrobial activity.

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.

Anti-inflammatory action of ark shell (Scapharca subcrenata) protein hydrolysate in LPS-stimulated RAW264.7 murine macrophages

Potential anti-inflammatory effects of ark shell (Scapharca subcrenata) protein hydrolysates were investigated. Ark shell protein hydrolysates were prepared using Alcalase® and pepsin and were designated ASAH and ASPH, respectively. The nitric oxide (NO) inhibitory activity of ASAH and ASPH was determined in lipopolysaccharides (LPS)-stimulated RAW264.7 murine macrophages, and the results showed that ASAH inhibited better NO inhibitory activity than ASPH. ASAH suppressed inflammatory mediator, a prostaglandin E2, secretion of pro-inflammatory cytokines (TNF-α, IL-1β, and IL-6), and production of reactive oxygen species (ROS) dose dependently. It inhibited the protein expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) and simulated heme oxygenase-1 (HO-1) protein expression. However, the pharmacological approach revealed that pretreatment with zinc protoporphyrin ІX (ZnPP), an inhibitor of HO-1, reversed the anti-inflammatory effect of ASAH. Moreover, ASAH upregulated phosphorylation of mitogen-activated protein kinases (MAPKs) including ERK1/2, JNK1/2, and p38 MAPK. To find out the role of MAPKs phosphorylation, MAPKs inhibitors were used, and the results showed that ASAH-mediated HO-1 protein expression and Nrf2 nuclear translocation were abolished. Taken all together, this study revealed that ASAH has a potential anti-inflammatory activity through regulation of the MAPK-dependent HO-1/Nrf2 pathway. PRACTICAL APPLICATIONS: Food-derived marine bioactive peptides, due to their pivotal role in biological activities, are gaining much attention recently. However, the anti-inflammatory activities of ark shell protein hydrolysates still remain to be investigated. This study investigated that ASAH shows potential anti-inflammatory activities through regulation of the MAPK-dependent HO-1/Nrf2 pathway in RAW264.7 murine macrophages. These findings indicated that ASAH may be used as a dietary supplement, functional food, and medicinal drug for the management of inflammation and inflammation-associated diseases.

One-pot synthesis and biochemical characterization of a magnetic collagenase nanoflower and evaluation of its biotechnological applications

Recently, hierarchical magnetic enzyme nanoflowers have been found extensive attention for efficient enzyme immobilization due to high surface area, low mass transfer limitations, active site accessibility, promotion of the enzymatic performance, and facile reusing. Herein, we report the purification of the Bacillus collagenase and then synthesis of magnetic cross-linked collagenase-metal hybrid nanoflowers (mcCNFs). The catalytic efficiency (k_cat/K_m) value of the immobilized collagenase was 2.2 times more than that of the free collagenase. The collagenase activity of mcCNFs enhanced about 2.9 and 4.6 at 85 and 90 °C, respectively, compared to free collagenase. Thermal stability of mcCNFs increased about 31% and 24% after 3 h of incubation at 50 and 60 °C, respectively. After 10 cycles of reusing, the mCNFs collagenase showed 83% of its initial activity. Results showed that the mcCNFs revealed 1.4 times more activity than the free collagenase in 0.16% protein waste. Furthermore, the hydrolysis value of chicken pie protein wastes by the immobilized enzyme obtained 4 times more than the free collagenase after 240 min incubation at 40 °C. Finally, our results showed that the construction of mcCNFs is an efficient method to increase the enzymatic performance and has excessive potential for the hydrolysis of protein wastes in the food industry.

Study of biological activities and physicochemical properties of Yamú (Brycon siebenthalae) viscera hydrolysates in sodium alginate-based edible coating solutions

The fishing industry produces waste such as viscera, which is an environmental problem for many countries. Obtaining protein from these wastes are useful for the food industry. In this study, the chemical composition, amino acid profile, solubility, digestibility and thermal properties of Yamú protein isolate (PI) and its hydrolysates obtained by enzymatic hydrolysis were characterized. The hydrolysates (0.05, 0.1, 0.5, 1 and 2% w/v) were mixed with a sodium alginate-based solution to form an edible coating solution (ECS). Antioxidant capacity antimicrobial activity, Zeta potential (ζ) and adsorption kinetics properties were determined. PI contains 88% (w/w) protein showing better solubility, digestibility and thermal stability properties. The hydrolysate concentrations with DPPH inhibitory ECS were 0.1 and 0.5% (w/v). The kinetic properties of ECS showed good stability and excellent adsorption. These results suggest that this Yamú protein has high nutritional potential as an ingredient for the production of functional foods.

Oral delivery of self-assembling bioactive peptides to target gastrointestinal tract disease

Peptides are known for their diverse bioactivities including antioxidant, antimicrobial, and anticancer activity, all three of which are potentially useful in treating colon-associated diseases. Beside their capability to stimulate positive health effects once released in the body, peptides are able to form useful nanostructures such as hydrogels. Combining peptide bioactivity and peptide gel-forming potentials can create interesting systems that can be used for oral delivery. This combination, acting as a two-in-one system, has the potential to avoid the need for delicate entrapment of a drug or natural bioactive compound. We here review the context and research progress, to date, in this area.

Antioxidant properties of Klunzinger's mullet (Liza klunzingeri) protein hydrolysates prepared with enzymatic hydrolysis using a commercial protease and microbial hydrolysis with Bacillus licheniformis

Antioxidant activity of Klunzinger's mullet (Liza klunzingeri) muscle hydrolysates obtained using Bacillus licheniformis fermentation and enzymatic hydrolysis was determined. Hydrolysates obtained after 6 days of fermentation with B. licheniformis showed the highest free radical scavenging activity, metal chelating ability and ferric reducing antioxidant power (FRAP) (P ≤ 0.05). Microbial fermentation led to a higher percentage of small peptides and higher solubility compared with Alcalase hydrolysis (P ≤ 0.05). Hydrolysates showing the highest antioxidant properties attenuated serum, liver, and kidney oxidative stress biomarkers in male Wister rats stressed by carbon tetrachloride (P ≤ 0.05). At 300 mg/kg oral administration, hydrolysates increased serum, renal, and hepatic total antioxidant capacity (TAC) (P ≤ 0.05) and reduced their elevated levels of malondialdehyde (MDA), nitric oxide (NO^•), and serum liver enzymes (AST, ALP, and ALT) (P ≤ 0.05). The hydrolysates were able to ameliorate hepatic damage by reducing necrosis, fatty changes, and inflammation. Results showed the antioxidant and hepato-toxic protective activities of Klunzinger's mullet muscle hydrolysates obtained using microbial fermentation, which may, therefore, potentially be considered as a functional food ingredient.

Pepsin Hydrolysis of Orange By-Products for the Production of Bioactive Peptides with Gastrointestinal Resistant Properties

Recently, the use of bioactive compounds in improving human health has received more attention. The aim of the present study was to hydrolyze orange seed proteins using pepsin enzyme to obtain bioactive peptides as well as to study the stability of such activity after simulated gastrointestinal digestion conditions. The method was optimized using different enzyme concentrations from 1% to 3%, hydrolysis times between 2 and 5 h, and an optimal temperature of 33 °C. Biological activities including α-glucosidase inhibition, α-amylase inhibition, Angiotensin I-Converting Enzyme (ACEI) inhibition, ferric reducing antioxidant power, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity were evaluated. According to the results, a significant higher value of the biological activity (p < 0.05) was observed using an enzyme ratio of 0.03 E/S and hydrolysis time of 3.5 h. After size-exclusion chromatography separation, fractions 45–49 and 50–54 showed the highest biological roles such as antioxidant, ACEI inhibitory, and hypoglycemic. Fractions with the highest biological activity were purified using RP-HPLC and analyzed using nano-liquid chromatography and mass spectrometry. The results obtained after simulated gastrointestinal digestion indicated that peptide fractions obtained after chromatographic separation significantly maintain their activity.

Recently isolated food-derived antihypertensive hydrolysates and peptides: A review

Hypertension is a non-communicable disease characterized by elevated blood pressure, and a prominent metabolic syndrome of modern age. Food-borne bioactive peptides have shown considerable potencies as suitable therapeutic agents for hypertension. The peptide inhibition of the angiotensin I-converting enzyme (ACE) from its default biochemical conversion of Ang I to Ang II has been studied and more relatively adopted in several studies. This review offers an examination of the isolation of concomitant proteins in foods, their hydrolysis into peptides and the biofunctionality checks of those peptides based on their anti-hypertensive potentialities. Furthermore, critical but concise details about methodologies and analytical techniques used in the purification of such peptides are discussed. This review is a beneficial literature supplement for scholars and provides functional awareness material for the food-aligned alternative therapy for hypertension. In addition, it points researchers in the direction of adopting food materials and associated by-products as natural sources for the isolation biologically active peptides.

Bioactive peptides from food fermentation: A comprehensive review of their sources, bioactivities, applications, and future development

Bioactive peptides (BPs) are specific protein fragments that exert various beneficial effects on human bodies and ultimately influence health, depending on their structural properties and amino acid composition and sequences. By offering promising solutions to solve diverse health issues, the production, characterization, and applications of food-derived BPs have drawn great interest in the current literature and are of particular interest to the food and pharmaceutical industries. The microbial fermentation of protein from various sources is indubitably a novel way to produce BPs with numerous beneficial health effects. Apart from its lower cost as compared to enzymes, the BPs produced from microbial fermentation can be purified without further hydrolysis. Despite these features, current literature shows dearth of information on the BPs produced from food via microbial fermentation. Hence, there is a strong necessity to explore the BPs obtained from food fermentation for the development of commercial nutraceuticals and functional foods. As such, this review focuses on the production of BPs from different food sources, including the extensively studied milk and milk products, with emphasis on microbial fermentation. The structure-activity (antihypertensive, antioxidant, antimicrobial, opiate-like, anti-inflammatory, anticancer/antiproliferative, antithrombotic, hypolipidemic, hypocholesterolemic, and mineral binding) relationship, potential applications, future development, and challenges of BPs obtained from food fermentation are also discussed.

Impact of Simulated Gastrointestinal Digestion on the Biological Activity of an Alcalase Hydrolysate of Orange Seed (Siavaraze, Citrus sinensis) by-Products

In this study, orange seed proteins were hydrolyzed by Alcalase enzyme at different enzyme concentrations 1-3% (v/w) and hydrolysis times (2-5 h), to obtain bioactive peptides showing antioxidant, Angiotensin-converting enzyme (ACE) -inhibitory, and hypoglycemic activities. The highest biological activities (p < 0.05) were achieved by using a hydrolysis time of 5 h and an enzyme concentration of 2%. Orange seed protein hydrolysate (OSPH) was prepared under these conditions, and peptides were isolated and purified by using size-exclusion chromatography and high-performance liquid chromatography, respectively. The fractions that showed the highest biological activities were analyzed by mass spectrometry in tandem, and a total of 63 peptide sequences were found. Moreover, the effect of simulated gastrointestinal digestion on the bioactivity of the fractions was studied, and the novel peptide sequences generated were also identified. Overall, despite there being some differences in the profile of peptide sequences obtained, the main results showed non-significant differences in the analyzed bioactivities after simulated gastrointestinal digestion.

Recovery of antioxidant and antimicrobial peptides through the reutilization of Nile perch wastewater by biodegradation using two Bacillus species

Nile perch wastewater was biodegraded using two Bacillus species to recover bioactive substances to enhance its reutilization value. The two Bacillus species successfully produced low-molecular-weight substances with a 47.8% degree of hydrolysis. The antioxidant activities of the Nile perch wastewater increased as the biodegradation proceeded, and the culture supernatant exhibited the highest DPPH (80.1%), ABTS (93.1%) and Fe²⁺ chelating (88.5%) antioxidant activities at 60 h. The antioxidant potential of the biodegraded Nile perch wastewater was found to be higher than those of other fish hydrolysates. Moreover, the biodegraded Nile perch wastewater exhibited effective antimicrobial activity against Vibrio vulnificus, exhibiting a minimal inhibitory concentration of 585 μg mL^-1. Two-dimensional thin layer chromatography analysis revealed the specific amino acids responsible for the antioxidant activity, and molecular-weight cut-off ultrafiltration revealed that the <2-kDa fraction exhibited the highest antioxidant activity with the lowest IC₅₀ values (0.43 and 0.22 mg mL^-1 for DPPH and ABTS antioxidant activities, respectively). This is the first report of the reutilization of Nile perch wastewater as a natural antioxidant and antimicrobial ingredient for nutraceuticals.

Marine Organisms as Potential Sources of Bioactive Peptides that Inhibit the Activity of Angiotensin I-Converting Enzyme: A Review

Angiotensin I-converting enzyme (ACE) is a paramount therapeutic target to treat hypertension. ACE inhibitory peptides derived from food protein sources are regarded as safer alternatives to synthetic antihypertensive drugs for treating hypertension. Recently, marine organisms have started being pursued as sources of potential ACE inhibitory peptides. Marine organisms such as fish, shellfish, seaweed, microalgae, molluscs, crustaceans, and cephalopods are rich sources of bioactive compounds because of their high-value metabolites with specific activities and promising health benefits. This review aims to summarize the studies on peptides from different marine organisms and focus on the potential ability of these peptides to inhibit ACE activity.

Challenges and opportunities regarding the use of alternative protein sources: Aquaculture and insects

The world population is constantly growing so that the needs of food, including protein sources, will also increase considerably in the coming years. Animal farming has been related to numerous environmental consequences such as soil erosion, exaggerated water consumption, generation of large quantities of waste and accumulation of greenhouse gases. This is a situation that demonstrates the suitability and importance of finding more sustainable protein alternatives without losing the quality and the nutritional benefits of current common protein sources. In this context, it is worth highlighting the potential of insects and products derived from aquaculture. Particularly, farmed aquatic food products can reduce the impact on wild fish stocks, whose overfishing may end up in an ecological collapse, and insects are easy to be reared and efficient in converting feed into biomass. However, there are still several challenges like the need to adapt technologies and methods for the production and well-characterization of the new ingredients, careful evaluation of the introduction of such new proteins in the diet and its safety of use, including potential allergies, and the acceptance by consumers.

Peptide identification in alcalase hydrolysated pollen and comparison of its bioactivity with royal jelly

Peptides with a similar antioxidant and ACE-inhibitory activity of royal jelly (RJ) generated from Alcalase hydrolysated pollen (AHP) were predicted by Response Surface Methodology (RSM). The model equations were proposed according to the effects of time and enzyme concentration on the antioxidant and ACE-inhibitory activity. The optimum values for Alcalase concentration and hydrolysis time were 1.5% and 4 h, respectively. Later, AHP was prepared and deproteinised to be further analysed using size-exclusion chromatography (SEC). After SEC separation, fractions with the highest activity of ACE-inhibitory, DPPH radical scavenging and ferric-reducing power were purified by RP-HPLC. The highest ACE-inhibitory and DPPH scavenging activity of fractions was found 100% and 66.61%, respectively. The most active fractions were analysed by nano-liquid chromatography and mass spectrometry in tandem (nLC-MS/MS) and a total of 195 peptide sequences were identified. The origins of all peptides were herbal proteins and certain coincidences with previously described bioactive sequences were discussed.

Antihypertensive activity of fish protein hydrolysates and its peptides

The rising interest to utilize nutritionally exorbitant fish proteins has instigated research activities in fish waste utilization. The development of newer technologies to utilize fish waste has fostered use of bioactive value-added products for specific health benefits. Enzymatically obtained Fish Protein Hydrolysate (FPH) is a rich source of biologically active peptides possessing anti-oxidant, anticancer, antimicrobial and anti-hypertensive activity. Isolating natural remedies to combat alarming negative consequences of synthetic drugs has been the new trend in current research promoting identification of antihypertensive peptides from FPH. In this review, we aim to culminate data available to produce antihypertensive peptides from FPH, its composition and potential to be used as a therapeutic agent. These purified peptides are known to be rich in arginine, valine and leucine. Reports reveal peptides with low molecular weight (<1 kDa) and shorter chain length (<20 amino acids) exhibited higher antihypertensive activity. As these peptides have proven Angiotensin Converting Enzyme - I inhibitory activity in vitro and in vivo, their potential to be used as antihypertensive drugs is outrageous. However, current focus on research in the field of molecular docking is necessary to have improved understanding of interaction of the peptides with the enzyme.

Extraction of unsaturated fatty acid-rich oil from common carp (Cyprinus carpio) roe and production of defatted roe hydrolysates with functional, antioxidant, and antibacterial properties

BACKGROUND

Common carp roe is a rich protein and oil source, which is usually discarded with no specific use. The aims of this study were to extract oil from the discarded roe and examine functional, antioxidant, and antibacterial properties of defatted roe hydrolysates (CDRHs) at various degrees of hydrolysis (DH).

RESULTS

Gas chromatography of fatty acid methyl esters revealed that common carp roe oil contained high levels of unsaturated fatty acids. The results of high-performance liquid chromatography-mass spectrometry indicated that enzymatic hydrolysis of defatted roe yielded higher content of essential amino acids. CDRHs displayed higher solubility than untreated defatted roe, which increased with DH. Better emulsifying and foaming properties were observed at lower DH and non-isoelectric points. Furthermore, water and oil binding capacity decreased with DH. CDRHs exhibited antioxidant activity both in vitro and in 5% roe oil-in-water emulsions and inhibited the growth of certain bacterial strains.

CONCLUSION

Common carp roe could be a promising source of unsaturated fatty acids and functional bioactive agents. Unsaturated fatty acid-rich oil extracted from common carp roe can be delivered into food systems by roe oil-in-water emulsions fortified by functional, antioxidant, and antibacterial hydrolysates from the defatted roe. © 2017 Society of Chemical Industry.

Peptidomic analysis of antioxidant and ACE-inhibitory peptides obtained from tomato waste proteins fermented using Bacillus subtilis

In this study, tomato seeds were obtained as by-products and submitted to fermentation with the proteolytic strain Bacillus subtilis A14h. The resulting peptide mixture was fractionated and purified through different chromatographic steps. Fractions were assayed for antioxidant and angiotensin converting enzyme (ACE)-inhibitory activities and peptides were identified by using nano-liquid chromatography coupled to mass spectrometry in tandem (nLC-MS/MS). Most of the identified peptides were smaller than 1000 Da and had different aromatic and hydrophobic amino acid residues. Their sequences were novel but some of them showed active domains previously reported in other bioactive peptides. The hexapeptide DGVVYY showed an IC₅₀ value of 2 µM in angiotensin-I converting enzyme (ACE-I) inhibitory activity, whereas the pentapeptide GQVPP displayed a 97% of DPPH activity at 0.4 mM. The results revealed that B. subtilis fermentation of tomato by-products could be a good strategy for obtaining added-value peptides that might be used as an ingredient in functional foods and nutraceuticals.

Novel bioactive peptides from enzymatic hydrolysate of Sardinelle (Sardinella aurita) muscle proteins hydrolysed by Bacillus subtilis A26 proteases

Sardinelle protein hydrolysate (SPH), prepared by treatment with Bacillus subtilis A26 proteases, was found to exhibit antibacterial, antioxidant and ACE-inhibitory activities. SPH, with a degree of hydrolysis of 4%, was fractionated by size exclusion chromatography on a Sephadex G-25 into five major fractions (F1-F5). F2, which exhibited the highest antibacterial and ACE-inhibitory activities, and F4, which exhibited the highest antibacterial and antioxidant activities, were further fractionated by reverse phase-high performance liquid chromatography (RP-HPLC) and then analysed using nano-ESI-LC-MS/MS to identify the sequences of peptides. Eight peptides were identified in the sub-fraction F2-A, nine peptides in the sub-fraction F4-B, and 45 peptides in F4-C. Identified peptides were found to share sequences with previously described bioactive peptides based on Biopep database. The results of this study suggest that SPH is a good source of natural bioactive peptides. Hence, it can be used as a potential ingredient in nutraceutical field.