Antioxidant and free radical-scavenging activities of smooth hound (Mustelus mustelus) muscle protein hydrolysates obtained by gastrointestinal proteases

Alkaline Proteases from Rose Snapper (Lutjanus guttatus): Evaluation of Their Stability to Chemical Denaturants and Potential Application to Hydrolyze Seafood Waste Proteins

Large quantities of by-products are generated after processing of rose snapper (Lutjanus guttatus), such as viscera, head, tail, skin, and bones, which are considered a potential source of valuable molecules. Therefore, the aim of the present study was the biochemical characterization of alkaline proteases isolated from the intestines of L. guttatus and the evaluation of their stability against different chemical denaturants (salts, surfactants/reducing agents, organic solvents, and commercial detergent formulations). In addition, the efficiency to hydrolyze proteins from rose snapper wastes (head, tail, skin, and muscle trimmings) by Alcalase® and alkaline protease extract (APE) isolated from Lutjanus guttatus intestine was evaluated. The APE exhibited a maximum activity at pH 12 and 45 °C and high stability at pH and temperature ranges from 9 to 12 and 10 to 40 °C, respectively. Assays with specific protease inhibitors indicated that trypsin and chymotrypsin are the main types of proteases in APE. An 80% of the proteolytic activity was retained in the presence of 25% NaCl and was stable in the presence of the reducing agent DTT; however, it lost around 70% of proteolytic activity in the presence of 2-mercaptoethanol. The enzymatic activity of APE was maintained above 60% in methanol, ethanol, and propanol as well as in liquid commercial detergents. Alkaline proteases from rose snapper exhibited higher hydrolytic efficiency, compared to the microbial enzyme Alcalase when protein from L. guttatus wastes were hydrolyzed. According to these results, the integral exploitation of rose snapper could be reached by proper usage of its by-products, creating a baseline to promote circular economy.

Spray-Dried Wheat Gluten Protein Hydrolysate Microcapsules: Physicochemical Properties, Retention of Antioxidant Capability, and Release Behavior Under Simulated Gastrointestinal Digestion Conditions

Wheat gluten is a by-product of the wheat starch industry, rich in bioactive peptides. Spray drying is an effective method for improving the stability of bioactive compounds. So, the aim of this study was to produce gluten hydrolysate by different proteases (alcalase, pancreatin, and trypsin) at different times (40-200 min). The hydrolysate with the strongest antioxidant potential (produced by pancreatin after 200 min of hydrolysis) was encapsulated by spray drying. The effect of wall material's type (maltodextrin, potato starch, and their combination at different ratios) on the encapsulation efficiency, physicochemical properties (moisture content, solubility, water activity, tapped and bulk density, and hygroscopicity), release behavior under simulated gastrointestinal digestion conditions, and morphology of microcapsules were evaluated. The microcapsules produced by maltodextrin and potato starch at a 30:70 ratio possessed the highest water activity (0.36), encapsulation efficiency (85.79%), and moisture content (8.2%). An increase in maltodextrin concentration increased the solubility, bulk, and tapped density. SEM images showed that microparticles were spherical with wrinkled surfaces. The microcapsules showed higher stability than free gluten hydrolysate. The combination of maltodextrin and potato starch at a 30:70 ratio could control the release of gluten hydrolysate under simulated gastrointestinal conditions. As a result, the use of maltodextrin and potato starch carriers at a 30:70 ratio in spray drying could effectively protect the bioactive properties of gluten hydrolysate and control its release.

Amelioration of Type 2 Diabetes Mellitus Using Rapeseed (Brassica napus)-Derived Peptides through Stimulating Calcium-Sensing Receptor: Effects on Glucagon-Like Peptide-1 Secretion and Hepatic Lipid Metabolism

The potential of rapeseed-derived peptides (RDPs) in the amelioration of type 2 diabetes mellitus (T2DM) has been hypothesized. However, the mechanisms of the intestinal endocrine hormones activated by RDPs have not been fully understood. This study aimed to explore the amelioration of T2DM and associated hepatic lipid metabolism disorders using RDPs by affecting glucagon-like peptide-1 (GLP-1) secretion. Eight RDPs were prepared by different stepwise enzymatic hydrolysis, wherein RCPP-3 (sequential using alcalase/flavourzyme) and RNPP-1 (sequential using alcalase/trypsin) maintained the normal blood glucose level, significantly increased the body weight (27.17 ± 0.19%) in T2DM mice compared to the positive group (p < 0.05). Western blotting and immunofluorescence experiments indicated that RCPP-3 and RNPP-1 regulated the intestinal endocrine hormones GLP-1 secretion through the calcium-sensing receptor (CaSR). Additionally, the PI3K-Akt pathway was significantly activated by GLP-1, leading to marked improvements in hepatic lipid parameters (TC, TG, LDL-c, and HDL-c) and mitigated fat accumulation (p < 0.05). Notably, the stimulating effect of RCPP-3 on GLP-1 was 10.05% ± 0.71% higher than RNPP-1. G2-R3, a fraction separated from RCPP-3, which contained 14 peptides with the best capacity to stimulate GLP-1 secretion, was identified using HPLC-QTOF-MS/MS. This study suggests the potential of RDPs as novel functional food supplements for ameliorating T2DM.

Investigating the possibility of increasing the microbial and oxidative stability of silver carp burgers using hydrolyzed protein of watermelon seeds

In this study, watermelon seeds (Citrullus lanatus) protein hydrolyzed (WSPH) was produced using microbial enzymes Alcalase and Protamex. Then, the effect of different concentrations of WSPH (0, 1, 2, and 3%) on the quality of the silver carp (Hypophthalmichthys molitrix) burger during refrigerated storage (4 ± 1 °C) was investigated. According to the results, WSPH by alcalase had significantly higher degree of hydrolysis and antioxidant activity (p < 0.05) and it was used for burger tests. The results showed that, the addition of WSPH was able to reduce the microbial, chemical spoilage and sensory score during 16 days compared to the control, and with increasing the concentration of WSPH, better results were observed (p < 0.05). According to the chemical, microbial and sensory indicators, WSPH at 3% could increase the shelf life of fish burgers up to 8 days compared to the control, and this treatment was within the permissible quality limit until the end of the refrigerated storage.

Graphical abstract

Evaluation of the Antioxidant and Anti-inflammatory Activity of the Anacyclus Valentinus L. Essential Oil and its Oxygenated Fraction

AIM AND OBJECTIVE

Synthetic antioxidants and anti-inflammatories are widely used by the food and pharmaceutical industries. Like any synthetic product, these are toxic and represent a significant health risk. The objective of this study was to determine the chemical composition of Anacyclus valentinus essential oil and its oxygenated fraction, as well as their in-vitro antioxidant and anti-inflammatory properties.

METHODS

The essential oil was hydrodistilled using a Clevenger-type device and the oxygenated fraction was obtained by column chromatography using diethyl ether. The essential oil and its oxygenated fraction were analysed by GC and GC/MS. The antioxidant activities were performed using three different methods Radical scavenging activity (DPPH), β-carotene bleaching test, and the Ferric-Reducing Antioxidant Power (FRAP), using BHT as a positive control. The activity of antiinflammatory of essential oil and its oxygenated fraction was assessed by the protein denaturation method using the diclofenac sodium as a positive control.

RESULTS

The essential oil of Anacyclus valentinus was represented mainly by oxygenated sesquiterpene compounds (37.7%), hydrocarbon sesquiterpenes (14.7%), oxygenated monoterpenes (18.4%) and non-terpenic compounds (15.6%). The oxygenated fraction was composed mainly of oxygenated sesquiterpenes (40.6%), oxygenated monoterpenes (38.5%), and non-terpene compounds (19.4%). Essential oil and oxygenated fraction showed antioxidant activity. The most potent activity was observed by the oxygenated fraction in the DPPH (IC50 = 8.2 mL/L) and β - carotene bleaching (IC50 = 5.6 mL/L) tests. While the essential oil of A. valentinus showed very good anti-inflammatory activity with an IC50 of 0.3 g/L higher than that of diclofenac (IC50= 0.53 g/L).

CONCLUSION

The results showed that the essential oil and the oxygenated fraction of A. valentinus are rich in sesquiterpene compounds and possess interesting antioxidant and anti-inflammatory properties. However, other studies are necessary to be able to offer these extracts to the pharmaceutical and food industries.

Structural Characteristics and Antioxidant Mechanism of Donkey-Hide Gelatin Peptides by Molecular Dynamics Simulation

This study aimed to explore the structural characteristics and antioxidant mechanism of donkey-hide gelatin peptides. After hydrolysis and ultrafiltration treatment, five gelatin peptides with different molecular weights (MWs) were obtained. Amino acid analysis showed that gelatin peptides with different MWs contained a large number of amino acids, including G, P, E, N, A, and R, and differences were noted in the content of various amino acids. Fourier transform infrared spectroscopy and circular dichroism revealed that these gelatin peptides differed in terms of the peak strength of functional groups and number of secondary structures. Moreover, 26 pentapeptides/hexapeptides were identified. Among them, we investigated by molecular docking how PGPAP, which has the best antioxidant activity, may interact with the Keap1 protein. The results showed that the PGPAP-Keap1 complex had a stable conformation, and Arg415, Gly462, Phe478, and Tyr572 were the key residues involved in the binding of the peptide PGPAP to Keap1. Our results demonstrated that PGPAP could serve as a bioactive peptide with antioxidant activity.

Eighteen Novel Bioactive Peptides from Monkfish (Lophius litulon) Swim Bladders: Production, Identification, Antioxidant Activity, and Stability

In the study, papain was chosen from five proteases to hydrolyze proteins of monkfish swim bladders for effectively utilizing monkfish (Lophius litulon) processing byproducts, and the hydrolysis conditions of papain were optimized as hydrolysis temperature of 65 °C, pH 7.5, enzyme dose 2.5% and time 5 h using single-factor and orthogonal experiments. Eighteen peptides were purified from the swim bladder hydrolysate of monkfish by ultrafiltration and gel permeation chromatography methods and identified as YDYD, QDYD, AGPAS, GPGPHGPSGP, GPK, HRE, GRW, ARW, GPTE, DDGGK, IGPAS, AKPAT, YPAGP, DPT, FPGPT, GPGPT, GPT and DPAGP, respectively. Among eighteen peptides, GRW and ARW showed significant DPPH· scavenging activities with EC₅₀ values of 1.053 ± 0.003 and 0.773 ± 0.003 mg/mL, respectively; YDYD, QDYD, GRW, ARW and YPAGP revealed significantly HO· scavenging activities with EC₅₀ values of 0.150 ± 0.060, 0.177 ± 0.035, 0.201 ± 0.013, 0.183 ± 0.0016 and 0.190 ± 0.010 mg/mL, respectively; YDYD, QDYD, ARW, DDGGK and YPAGP have significantly O2-· scavenging capability with EC₅₀ values of 0.126 ± 0.0005, 0.112 ± 0.0028, 0.127 ± 0.0002, 0.128 ± 0.0018 and 0.107 ± 0.0002 mg/mL, respectively; and YDYD, QDYD and YPAGP showed strong ABTS⁺· scavenging ability with EC₅₀ values of 3.197 ± 0.036, 2.337 ± 0.016 and 3.839 ± 0.102 mg/mL, respectively. YDYD, ARW and DDGGK displayed the remarkable ability of lipid peroxidation inhibition and Ferric-reducing antioxidant properties. Moreover, YDYD and ARW can protect Plasmid DNA and HepG2 cells against H₂O₂-induced oxidative stress. Furthermore, eighteen isolated peptides had high stability under temperatures ranging from 25-100 °C; YDYD, QDYD, GRW and ARW were more sensitive to alkali treatment, but DDGGK and YPAGP were more sensitive to acid treatment; and YDYD showed strong stability treated with simulated GI digestion. Therefore, the prepared antioxidant peptides, especially YDYD, QDYD, GRW, ARW, DDGGK and YPAGP from monkfish swim bladders could serve as functional components applied in health-promoting products because of their high-antioxidant functions.

Bioactive characterization and optimization of Tamarindus indica seed protein hydrolysate: technology and application of natural enzymes

Tamarind seeds are one of the major sources of different nutrients and minerals and are used as antioxidant components in various food products. Bioactive peptides are released by enzymatic hydrolysis of major food proteins followed by different separation techniques to isolate them from the mixture of other components. Further incorporation of bioactive peptides in various food products may lead to more diversification, fulfilling different nutritional requirements, and promoting health benefits. The objective of this study was to optimize the parameters for the formation of tamarind protein hydrolysates with the use of pepsin and trypsin. It was observed that pepsin and trypsin derived hydrolysate showed the maximum degree of hydrolysis and other bioactive characteristics (DPPH activity, reducing power, ABTS activity, and antidiabetic activity) under optimized conditions. High-performance liquid chromatography was performed for amino acid profiling on trypsin derived protein hydrolysate. From this study, pepsin and trypsin derived hydrolysate can be considered as a rich source of natural antioxidants for developing food formulation.

Enzymatic hydrolysis re-endows desalted duck egg white nanogel with outstanding foaming properties

Heat-induced gel-assisted desalination could efficiently and inexpensively remove salt from salted egg whites. However, it was at the expense of the excellent foaming properties of egg whites, caused by the denaturation and aggregation of proteins during heating treatment. Hence, in this current work, the enzymatic treatment was used to re-endow duck egg white nanogels (DEWN) with outstanding foaming properties. We found that low levels of hydrolysis (DH = 2.27 %) could dramatically improve the foaming capability (FC), reaching >200 %, which also enhanced the foaming stability (FS). As the hydrolysis time extended, the adsorption and diffusion rate of the supernatant on the interface increased and performed high elasticity. The dilatational rheology and Lissajous plots were explored to investigate the nonlinear dilatational rheological behaviors of the air/water interface stabilized by the hydrolysed samples. Finally, we evaluated the effect of pH on foaming properties and found that the FC could exceed 250 %, and the FS was close to 80 % at pH = 5. These encouraging results showed that simple enzymatic treatment could revive nanogels from their dissatisfied foaming properties. In this work, gel-assisted desalination combined with enzyme treatment significantly promotes the high-quality and high-value utilization of salted egg white.

Evaluation of Plant Protein Hydrolysates as Natural Antioxidants in Fish Oil-In-Water Emulsions

In this work, we evaluated the physical and oxidative stabilities of 5% w/w fish oil-in-water emulsions stabilized with 1%wt Tween20 and containing 2 mg/mL of protein hydrolysates from olive seed (OSM–H), sunflower (SFSM–H), rapeseed (RSM–H) and lupin (LUM–H) meals. To this end, the plant-based substrates were hydrolyzed at a 20% degree of hydrolysis (DH) employing a mixture 1:1 of subtilisin: trypsin. The hydrolysates were characterized in terms of molecular weight profile and in vitro antioxidant activities (i.e., DPPH scavenging and ferrous ion chelation). After incorporation of the plant protein hydrolysates as water-soluble antioxidants in the emulsions, a 14-day storage study was conducted to evaluate both the physical (i.e., ζ-potential, droplet size and emulsion stability index) and oxidative (e.g., peroxide and anisidine value) stabilities. The highest in vitro DPPH scavenging and iron (II)-chelating activities were exhibited by SFSM–H (IC₅₀ = 0.05 ± 0.01 mg/mL) and RSM–H (IC₅₀ = 0.41 ± 0.06 mg/mL). All the emulsions were physically stable within the storage period, with ζ-potential values below −35 mV and an average mean diameter D[4,3] of 0.411 ± 0.010 μm. Although LUM–H did not prevent lipid oxidation in emulsions, OSM–H and SFSM–H exhibited a remarkable ability to retard the formation of primary and secondary lipid oxidation products during storage when compared with the control emulsion without antioxidants. Overall, our findings show that plant-based enzymatic hydrolysates are an interesting alternative to be employed as natural antioxidants to retard lipid oxidation in food emulsions.

Preparation and identification of an antioxidant peptide from wheat embryo albumin and characterization of its Maillard reaction products

Wheat embryo albumin (WEA) extracted from wheat embryo possesses multiple effects including antioxidant, anti-inflammatory, and immunoregulatory effects. In this study, a single factor experiment was conducted to determine the optimal enzymolysis conditions of WEA. Five components (F1-F5) were obtained via ultrafiltration, among which F3 (molecular weight 3-5 kDa) displayed the best antioxidant activity. WEA and F3 were characterized by transmission electron microscopy, scanning electron microscopy, circular dichroism spectrum analysis, and amino acid composition tests. Results revealed that F3 significantly increased the contents of β-tablets, aromatic amino acids, and hydrophobic amino acids compared to WEA. LC-MS/MS analysis demonstrated that F3 had more tyrosine and histidine moieties than WEA. Moreover, analysis of the Maillard reaction products (MRPs) showed that F3-MRPs had strong browning strength, ultraviolet absorption, higher number of free amino acids, and umami amino acid ratio compared with WEA. In conclusion, enzymolysis can improve the functional properties of WEA, which broadens the application spectrum of WEA in food and pharmaceutical fields. PRACTICAL APPLICATION: This study provides a new approach for identifying potential antioxidants and developing functional foods from WEA, and broadens the application spectrum of wheat germ resources.

In vitro dynamic digestion and antifatigue effects of wheat germ albumin

Wheat germ protein including wheat germ albumin (WGA) demonstrated extensive biological activities. In vitro dynamic digestion of was carried out under simulated gastrointestinal conditions. Antifatigue effects of WGA were evaluated...

Use composite coating of chitosan-chia seed gum enriched with microliposomes of Bay laurel essential oil to increase the shelf life of quail fillets

In this study, the effect of composite chitosan-chia seed coating (CH-CG) with Bay laurel (Laurus nobilis) essential oil (BE) in two forms including free and nanocapsulated on the shelf life of quail fillets during the 16-day refrigeration (4 ± 1℃) period was investigated. For this purpose, first, BE was extracted by Clevenger apparatus. Then, nanoliposomes BE were produced, and the properties of BE and nanoliposomes BE were investigated. In order to investigate the shelf life of quail, 6 treatments were produced including 1: control (C), 2: CH-CG, CH-CG+BE at 800 ppm, 3: CH-CG+BE at 1600 ppm, 4: CH-CG+nano BE at 800 ppm, 5: CH-CG+nano BE at 1600 ppm, and periodically chemical parameters (peroxide value, free fatty acid, total volatile basic nitrogen, texture firmness, and chewing ability) and microbial (total viable bacteria (TVC) and psychrotrophic bacteria), and the effect of different treatments on control in Escherichia coli and Staphylococcus aureus inoculated populations in quail was also investigated. The BE had high antioxidant and antimicrobial properties. The particle size and microencapsulation efficiency of BE nanoliposome were 98.3 nm and 75.95%, respectively. The results of chemical and microbial analysis showed that in general, the coating with essential oil slowed down the increasing trend of oxidation and microbial indices compared to the control treatment and nanocapsulation of essential oil has increased its antimicrobial and antioxidant properties (p < .05). At the end of storage period, in all tests, treatments of 3, 4, and 5 had the allowed microbial and chemical range and they also inhibited the growth of these bacteria (p < .05). Overall, considering the higher sensory score of treatment 4 and economic efficiency, it seems that this treatment can be used as a natural preservative in the meat industry.

Synergistic inhibitory effects of the oxyresveratrol and dacarbazine combination against melanoma cells

Various therapies have been developed to target malignant melanoma, which is associated with a high mortality rate worldwide. Although dacarbazine (DTIC) is employed for treating melanoma, it is associated with several side effects. Hence, patients with melanoma are co-treated with additional drugs to mitigate the side effects of DTIC. In the present study, synergistic therapeutic effects of the DTIC/oxyresveratrol (ORT) combination were examined using the human malignant melanoma WM-266-4 cell line. Treatment with ORT and DTIC inhibited the proliferation of WM-266-4 cells. Compared with those in the ORT- and DTIC-treated groups, the proportion of cells arrested at the S phase, as well as apoptotic rates, were increased in the ORT and DTIC co-treatment group. In WM-266-4 cells, synergistic proliferation-inhibitory activities of the ORT/DTIC combination were assessed based on cell viability and migration, antioxidant capacity, cytokine production, cell cycle arrest, apoptotic rate and protein expression through WST-1 assay, wound healing assay, flow cytometry and western blotting. Furthermore, the expression levels of proteins, including NOTCH, involved in the pathogenesis of solid cancers, such as melanoma, were examined. Overall, the ORT/DTIC combination synergistically promoted cell cycle arrest at the S phase and the apoptosis of WM-266-4 cells. Thus, this combination treatment may serve as a novel therapeutic strategy for treating malignant melanoma.

Characterization of Protein Hydrolysates from Fish Discards and By-Products from the North-West Spain Fishing Fleet as Potential Sources of Bioactive Peptides

Fish discards and by-products can be transformed into high value-added products such as fish protein hydrolysates (FPH) containing bioactive peptides. Protein hydrolysates were prepared from different parts (whole fish, skin and head) of several discarded species of the North-West Spain fishing fleet using Alcalase. All hydrolysates had moisture and ash contents lower than 10% and 15%, respectively. The fat content of FPH varied between 1.5% and 9.4% and had high protein content (69.8-76.6%). The amino acids profiles of FPH are quite similar and the most abundant amino acids were glutamic and aspartic acids. All FPH exhibited antioxidant activity and those obtained from Atlantic horse mackerel heads presented the highest 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, reducing power and Cu2+ chelating activity. On the other hand, hydrolysates from gurnard heads showed the highest ABTS radical scavenging activity and Fe2+ chelating activity. In what concerns the α-amylase inhibitory activity, the IC50 values recorded for FPH ranged between 5.70 and 84.37 mg/mL for blue whiting heads and whole Atlantic horse mackerel, respectively. α-Glucosidase inhibitory activity of FPH was relatively low but all FPH had high Angiotensin Converting Enzyme (ACE) inhibitory activity. Considering the biological activities, these FPH are potential natural additives for functional foods or nutraceuticals.

Production of Alkaline Proteases using Aspergillus sp. Isolated from Injera: RSM-GA Based Process Optimization and Enzyme Kinetics Aspect

Alkaline proteases are well known to be significant industrial enzymes. This study focused on isolating the fungus producing proteases from, a typical Ethiopian food, Injera. Further, the process optimization for protease production using response surface methodology (RSM) and the characterization of the acquired protease were investigated. The 18S rDNA gene sequence homology of the fungus isolate revealed that it was Aspergillus sp. Further, it was deposited in NCBI GenBank with accession number MK4262821. Using the isolate, owing to maximize the protease production, the independent process parameters, temperature, pH, and sucrose concentration were optimized using RSM followed by a genetic algorithm (GA). Based on the statistical approach by RSM-GA optimization, maximum enzyme activity (166.4221 U/ml) was found at 30.5 °C, pH 8.24, and 0.316% sucrose concentration. Also, the crude cocktail of enzymes acquired from optimal condition was partially purified using ammonium which showed that the increased activity by 1.96-fold. Considerably, the partially purified enzyme exhibited stable performance during the temperature range 30-60 °C, pH range 7-10, and NaCl concentration of 0.5-2 mM. Also, the antioxidant activity, degree hydrolysis for the protein, Michaelis-Menten (M-M) kinetic parameters, and activation energy were determined for the obtained enzyme cocktail. It showed that the M-M kinetic parameters, Km (5.54 mg/ml), and Vmax (24.44 mg/ml min) values were observed. Using Arrhenius law, the value of activation energy for the enzyme cocktail was determined as 32.42 kJ/mol.

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.

Fractionation of Flaxseed-Derived Bioactive Peptides and Their Influence on Nanoliposomal Carriers

This study addressed the extraction, enzymatic hydrolysis, and production of peptide fractions (PF) from defatted flaxseed meal and their loading into nanoliposomes. Enzymatic hydrolysis significantly increased the free hydrophobic (from 19 to 134 mg/g) and antioxidant (from 8 to 46 mg/g) amino acids. The PF with lower molecular weights (MW < 10 kDa) had the highest scavenging capacity of DPPH^- free radicals (61.82%), ABTS⁺ (86.37%), Trolox equivalent antioxidant capacity, TEAC (2.34 mM), hydroxyl (61.91%), reducing power (0.94 Abs₇₀₀), total antioxidant activity (1.76 Abs₆₉₅), nitric oxide (49.9%), iron (69.34%), and copper (24.58%) chelating activities compared with other fractions. The physical properties (such as particle size and polydispersity index), stability, and encapsulation efficiency of nanoliposomes were affected by temperature, stress type (freeze and thaw tension), MW, and in vitro conditions (release of PF in simulated biological fluids at different times). Besides, the Fourier-transform infrared spectroscopy (FTIR) results showed the placement of peptides inside the polar regions and the bilayer membrane. The scanning electron microscopy (SEM) images of nanocarriers indicated agglomerated and relatively spherical structures. Our findings revealed the efficiency of nanoliposomes as appropriate carriers for the delivery of peptide fractions with the highest antioxidant activity.

Comparison of physicochemical and biochemical properties of natural and arginine-modified melanin from medicinal mushroom Ganoderma lucidum

Melanin is a hydrophobic biomolecule produced widely in fungi. Compared with other fungi, health benefits have been associated with medicinal mushrooms, which may provide an excellent source of natural melanin. Nevertheless, the hydrophobicity of melanin may limit its applications. Consequently, the present study was carried out on isolation of melanin from the medicinal mushroom Ganoderma lucidum (GLM) and modification with arginine to improve its solubility. The physicochemical and biochemical properties of melanin were evaluated including structural characterization, solubility, stability, antioxidant activities, and inhibitory effect on pancreatic lipase activity. Arginine-modified melanin showed better solubility, higher color value, stronger antioxidant activity, and stronger inhibitory effect on pancreatic lipase activity in vitro than GLM. In addition, both have good stability in the dark and natural light. These results opened possibilities for providing an excellent source of natural melanin in health food or food additives fields.

Effect of a dietary supplement composed of hydrolyzed milk proteins and vanillin on the reduction of infection and oxidative stress induced by chemotherapy

This study evaluates the antioxidant and antibacterial activity of a mixture of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin in vitro and in vivo to design a chemoprotective supplement for reducing the infection and oxidative stress induced by chemotherapy. The designed supplement showed significant antibacterial activity against E. coli. The supplement with the highest concentration exhibited considerable antioxidant activity in (2,2-diphenyl-1-picrylhydrazyl) DPPH free radicals, (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) ABTS, and reducing power assays. In the biochemical analysis of liver homogenate, the supplement 3 increased the level of enzymes Catalase (CAT), Glutathione peroxidase (GPx), Superoxide dismutase (SOD), and also the Ferric Reducing Ability of Plasma (FRAP) while decreased thiobarbituric acid reactive substances (TBARS) in comparison to paclitaxel group, indicative of activity against oxidative stress. Antibacterial and antioxidant activity of the designed supplement makes it a good candidate for use as a functional food to reduce the side effects of chemotherapy. PRACTICAL APPLICATIONS: A dietary supplement composed of lactoferrin hydrolysate (LfH), whey protein hydrolysate (WPH) and vanillin showed antibacterial activity against E. coli and S. aureus in vitro. The studied supplement also exhibited significant antioxidant properties in the model system and anti-oxidative stress activity in mice exposed to paclitaxel. This supplement has a potential for use in the food matrix to reduce the chemotherapy side effects and to act as a chemoprotective agent.

Optimization of Extraction of Bioactive Peptides from Monkfish (Lophius litulon) and Characterization of Their Role in H2O2-Induced Lesion

Background: Marine fish meat has been widely used for the extraction of bioactive peptides. This study was aimed to optimize the preparation of monkfish muscle peptides (LPs) using response surface methodology (RSM) and explore the antioxidant activities of <1 kDa LPs. Methods: Peptides were prepared from the muscles of monkfish (Lophius litulon), and five proteases were tested to hydrolyze muscle proteins. The hydrolysate that was treated using neutrase showed the highest degree of hydrolysis (DH) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) scavenging activities. Results: The optimized conditions were as follows: water/material ratio of 5.4:1, a time span of 5 h, pH of 7.0, enzyme concentration of 2000 U/g, and temperature of 45 °C; the maximum DPPH scavenging activity and DH were 92.861% and 19.302%, respectively. LPs exhibited appreciable antioxidant activities, including DPPH radical, hydroxyl radical, 2,2′-azinobis-3-ethylbenzthiazoline-6-sulphonate (ABTS) radical, and superoxide anion scavenging activities. LPs attenuated H₂O₂-related oxidative injury in RAW264.7 cells, reduced the reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and increased the superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and catalase (CAT) levels. Conclusion: We concluded that LPs could be an ideal source of bioactive peptides from monkfish and also have pharmaceutical potential.

Production and Characterization of Antioxidative Hydrolysates and Peptides from Corn Gluten Meal Using Papain, Ficin, and Bromelain

There has been a growing interest in developing natural antioxidants with high efficiency and low cost. Bioactive protein hydrolysates could be a potential source of natural and safer antioxidants. The objectives of this study were to hydrolyze corn gluten meal using three plant-derived proteases, namely papain, ficin, and bromelain, to produce antioxidative hydrolysates and peptides and to characterize the antioxidant performances using both chemical assays and a ground meat model. The optimum hydrolysis time for papain was 3 h, and for ficin and bromelain was 4 h. The hydrolysates were further separated by sequential ultrafiltration to 5 hydrolysate fractions named F1 to F5 from low molecular weight (MW) (<1 kDa) to high MW range (>10 kDa), which were further characterized for TPC, free radical scavenging capacity against DPPH and ABTS, and metal chelating activity. The fraction F4 produced by papain (CH-P4), F1 produced by ficin (CH-F1), and F3 produced by bromelain (CH-B3) showed the strongest antioxidant activity and yield, respectively. These three fractions were incorporated into ground pork to determine their inhibition effects on lipid oxidation during a 16-day storage period. The inhibition effect was enhanced with the addition of higher amount of hydrolysate (e.g., 1000 vs. 500 mg/kg). The CH-P4 reduced lipid oxidation in ground meat by as much as 30.45%, and CH-B3 reduced oxidation by 27.2% at the same level, but the inhibition was only 13.83% with 1000 mg/kg of CH-F1. The study demonstrated that CGM protein hydrolysates and peptides could be used as naturally derived antioxidant in retarding lipid oxidation and improving product storage stability.

Collagen Peptides from Swim Bladders of Giant Croaker (Nibea japonica) and Their Protective Effects against H2O2-Induced Oxidative Damage toward Human Umbilical Vein Endothelial Cells

Five different proteases were used to hydrolyze the swim bladders of Nibea japonica and the hydrolysate treated by neutrase (collagen peptide named SNNHs) showed the highest DPPH radical scavenging activity. The extraction process of SNNHs was optimized by response surface methodology, and the optimal conditions were as follows: a temperature of 47.2 °C, a pH of 7.3 and an enzyme concentration of 1100 U/g, which resulted in the maximum DPPH clearance rate of 95.44%. Peptides with a Mw of less than 1 kDa (SNNH-1) were obtained by ultrafiltration, and exhibited good scavenging activity for hydroxyl radicals, ABTS radicals and superoxide anion radicals. Furthermore, SNNH-1 significantly promoted the proliferation of HUVECs, and the protective effect of SNNH-1 against oxidative damage of H2O2-induced HUVECs was investigated. The results indicated that all groups receiving SNNH-1 pretreatment showed an increase in GSH-Px, SOD, and CAT activities compared with the model group. In addition, SNNH-1 pretreatment reduced the levels of ROS and MDA in HUVECs with H2O2-induced oxidative damage. These results indicate that collagen peptides from swim bladders of Nibea japonica can significantly reduce the oxidative stress damage caused by H2O2 in HUVECs and provides a basis for the application of collagen peptides in the food industry, pharmaceuticals, and cosmetics.

Marine Bioactive Peptides-An Overview of Generation, Structure and Application with a Focus on Food Sources

The biggest obstacles in the application of marine peptides are two-fold, as in the case of non-marine plant and animal-derived bioactive peptides: elucidating correlation between the peptide structure and its effect and demonstrating its stability in vivo. The structures of marine bioactive peptides are highly variable and complex and dependent on the sources from which they are isolated. They can be cyclical, in the form of depsipeptides, and often contain secondary structures. Because of steric factors, marine-derived peptides can be resistant to proteolysis by gastrointestinal proteases, which presents an advantage over other peptide sources. Because of heterogeneity, amino acid sequences as well as preferred mechanisms of peptides showing specific bioactivities differ compared to their animal-derived counterparts. This review offers insights on the extreme diversity of bioactivities, effects, and structural features, analyzing 253 peptides, mainly from marine food sources. Similar to peptides in food of non-marine animal origin, a significant percentage (52.7%) of the examined sequences contain one or more proline residues, implying that proline might play a significant role in the stability of bioactive peptides. Additional problems with analyzing marine-derived bioactive peptides include their accessibility, extraction, and purification; this review considers the challenges and proposes possible solutions.

Chemical Variability and Antioxidant Activities of the Essential Oils of the Aerial Parts of Ammoides verticillata and the Roots of Carthamus caeruleus and their Synergistic Effect in Combination

AIM AND OBJECTIVE

Oxidative stress is implicated in the development and progression of many diseases. Some of the appropriate actions that could taken to resolve the problem of these diseases are search for new antioxidant substances isolated from plants. The aims of this study were to research the intraspecies variations of A. verticillata and C. caeruleus essential oils from 8 locations using statistical analysis, the in vitro antioxidant properties of collective essential oils and in combinations.

MATERIALS AND METHODS

The essential oils were analyzed by GC and GC-MS. The intraspecies variations of the essential oil compositions were discussed using principal component analysis (PCA) and cluster analysis (CA). The antioxidant properties were evaluated DPPH-radical scavenging activity and β-carotene bleaching test.

RESULTS

The main components of Ammoides verticillata collective essential oil (Coll EO) were thymol (30.5%), carvacrol (23.2%), p-cymene (13.1%), limonene (12.5%) and terpinene-4-ol (12.3%). While roots of Carthamus caeruleus essential oil were dominated by carline oxide (86.2%). The chemical variability allowed the discrimination of two main Groups for both Coll EOs. A direct correlation between the altitudes, climate and the chemical compositions was evidenced. Ammoides verticulata and Carthamus caeruleus Coll Eos showed good antioxidant activity. In binary mixture, the interaction between both Coll Eos and between oils rich of thymol and/or carvacrol with carlina oxide produced the best synergistic effects compared to individual essential oils and the synthetic antioxidant (BHT).

CONCLUSION

Ammoides verticillata and Carthamus caeruleus essential oil blends can be used as a natural food preservative and alternative to chemical antioxidants.

Evaluation of Tenebrio molitor protein as a source of peptides for modulating physiological processes

The increasing world population has led to the need to search for new protein sources, such as insects, the harvesting of which can be economical and environmentally sustainable. This study explores the biological activities (angiotensin-converting enzyme (ACE) inhibition, antioxidant capacity, and dipeptidyl peptidase IV (DPP-IV) inhibition) of Tenebrio molitor hydrolysates produced by a set of food-grade proteases, namely subtilisin, trypsin, ficin and flavourzyme, and the degree of hydrolysis (DH), ranging from 5% to 20%. Trypsin hydrolysates exhibited the highest ACE inhibitory activity at a DH of 10% (IC₅₀ 0.27 mg mL^-1) in the experimental series, which was attributed to the release of short peptides containing Arg or Lys residues in the C terminus, and described as the ACE-inhibition feature. The levels of in vitro antioxidant activities were comparable to those reported for insect species. Subtilisin and trypsin hydrolysates at a DH of 10% displayed optimal DPPH scavenging and ferric reducing activities, which was attributed to the presence of 5-10-residue active peptides, as reported in the literature. Iron chelating activity was significantly favoured by increasing the DH, attaining a minimal IC₅₀ of 0.8 mg mL^-1 at a DH of 20% regardless of the enzymatic treatment. Similarly, in vitro antidiabetic activity was significantly improved by extensive hydrolysis, and, more specifically, the presence of di- and tripeptides. In this regard, the combined treatment of subtilisin-flavourzyme at a DH of 20% showed maximal DPP-IV inhibition (IC₅₀ 2.62 mg mL^-1). To our knowledge, this is the first study evaluating the DPP-IV activity of Tenebrio molitor hydrolysates obtained from these commercial proteases. We conclude that Tenebrio molitor hydrolysates produced with food-grade proteases are a valuable source of active peptides that can be used as functional ingredients in food and nutraceutical preparations.

Dissecting the Interaction Deficiency of a Cartilaginous Fish Digestive Lipase with Pancreatic Colipase: Biochemical and Structural Insights

A full-length cDNA encoding digestive lipase (SmDL) was cloned from the pancreas of the smooth-hound (Mustelus mustelus). The obtained cDNA was 1350 bp long encoding 451 amino acids. The deduced amino acid sequence has high similarity with known pancreatic lipases. Catalytic triad and disulphide bond positions are also conserved. According to the established phylogeny, the SmDL was grouped with those of tuna and Sparidae lipases into one fish digestive lipase cluster. The recently purified enzyme shows no dependence for bile salts and colipase. For this, the residue-level interactions between lipase-colipase are yet to be clearly understood. The structural model of the SmDL was built, and several dissimilarities were noticed when analyzing the SmDL amino acids corresponding to those involved in HPL binding to colipase. Interestingly, the C-terminal domain of SmDL which holds the colipase shows a significant role for colipase interaction. This is apt to prevent the interaction between fish lipase and the pancreatic colipase which and can provide more explanation on the fact that the classical colipase is unable to activate the SmDL.

Antiradical Activity of Hydrolysates and Extracts from Mollusk A. broughtonii and Practical Application to the Stabilization of Lipids

The antiradical properties of hydrolysates and hydrothermal extracts of bivalve mollusks (Anadara broughtonii) from the Far Eastern Region of Russia and their influence on lipid oxidation in mayonnaise were investigated. The radical binding activity of hydrolysates and extracts of A. broughtonii varies from 55% to 89%. The maximum radical-binding activity was observed for acid hydrolysates. The antiradical efficiency of acid hydrolysates is 35%–41% of the BHT (butylhydroxytoluene) index. The antiradical activity depends on the (method of) technological and biotechnological processing of raw materials. Acid and enzymatic hydrolysates and hydrothermal extracts of A. broughtonii in mayonnaise slow down the process of oxidation of lipids and hydrolysis of triglycerides. Acid hydrolysates reduce the speed of oxidation and hydrolysis of lipids in mayonnaise more efficiently than the enzymatic hydrolysates.

Kefir fermentation as a bioprocess to improve lentils antioxidant properties: is it worthwhile?

Abstract Kefir, a consortium of acetic and lactic bacteria and yeasts, is versatile for biotransformation of vegetable substrates and may improve their bioactive properties. Lentil is a legume rich in vitamins, minerals, complex carbohydrates and proteins, making it an excellent substrate for fermentation and obtaining bioactive molecules. We report the effect of different process variables on antioxidant properties of lentil extracts obtained using kefir as a biotransformation agent and experimental design. The results showed that the factors agitation (rpm) and incubation temperature exerted significant effects. Incubation temperature of 28 °C and agitation of 75 rpm were the most suitable conditions for kefir fermentation and maximizing the antioxidant properties of the fermented lentils. The highest antioxidant activities for fermented products were 4128.39, 35.87 and 23.20 μmol of Trolox equivalents per gram of sample (μmoL TE g-1) measured by Total Antioxidant Capacity, FRAP and DPPH-radical scavenging methods, respectively. Additionally, we detected that the initial fermentation times (in the first six hours) were enough to positively affect the antioxidant properties of the lentil extracts, reaching a percentage increase of up to 270% in the antioxidant activity of the fermented products in relation to those non-fermented samples.

In Vitro Anticoccidial Activity of Olive Pulp (Olea europaea L. var. Chemlal) Extract Against Eimeria Oocysts in Broiler Chickens

AIM

The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally.

MATERIALS AND METHODS

The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography-mass spectrometry with electrospray ionisation (HPLC-ESI-MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm.

RESULTS

Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R² = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity.

CONCLUSION

To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens.

Size-dependent whitening activity of enzyme-degraded fucoidan from Laminaria japonica

Fucoidan from Laminaria japonica is a kind of sulfate polysaccharide with high molecular weight (MW) and broad bioactivities. This study was performed to investigate the relationship between MW and whitening activity of fucoidan and to exploit a novel functional ingredient for whitening cosmetics. High sulfate content fucoidan was enzymic degraded by Flavobacterium RC2-3 produced fucoidanase. Two hours were enough for the enzyme degradation to achieve degraded fucoidan with favorable tyrosinase inhibitory ability. The whitening activity of different MW fucoidan fractions were evaluated by their tyrosinase inhibitory ability, antioxidant activity and cellular melanogenesis inhibitory ability. Results showed that in the MW range above 5 kDa, the smaller MW of fucoidan were related to the better whitening activity. The fucoidan fraction with the MW between 5-10 kDa, presented the best tyrosinase inhibitory activity (62.0%), antioxidant activity (48.3%) and excellent anti-melanogenesis ability in B16 cells, which could be applied as the whitening factor in cosmetics development.