Production and characterization of encapsulated antioxidative protein hydrolysates from Whitemouth croaker (Micropogonias furnieri) muscle and byproduct

Chitosan-coated nanoliposome: An approach for simultaneous encapsulation of caffeine and roselle-anthocyanin in beverages

The objective of the present research was to develop chitosan-coated nanoliposomes using a modified heating method as a delivery system for simultaneous encapsulation of caffeine and roselle anthocyanin to fortify beverage. Response surface methodology was used to ascertain the optimized formulation, aiming to maximize the encapsulation efficiency, minimize the particle size, and maximize the zeta potential. The liposomes fabricated under the optimized conditions (lecithin to cholesterol ratio of 13 and wall to core ratio of 2.16) showed encapsulation efficiency values of 66.73 % for caffeine and 97.03 % for anthocyanin, with a size of 268.1 nm and a zeta potential of -39.11 mV. Fourier transform infrared spectroscopy confirmed the formation of hydrogen bonds between the polar sites of lecithin and the loaded core compounds. Thermal analysis suggested the successful encapsulation of the caffeine and anthocyanin. Transmission and scanning electron microscopy images confirmed a uniform spherical shape with a smooth surface. Fortifying the model beverage with the liposome and the chitosan-coated nanoliposome revealed higher values of encapsulation efficiency of anthocyanin (70.33 ± 3.11 %), caffeine (86.37 ± 2.17 %) and smaller size (280.5 ± 0.74 nm) of the chitosan-coated nanoliposomes at the end of 60the days. A hedonic sensory test of the fortified beverage with chitosan-coated nanoliposomes confirmed an improvement in the organoleptic properties of the beverage by masking its bitterness (receiving three more sensory scores in perceiving the bitterness intensity). Overall, our study indicates that the high potential of the chitosan-coated nanoliposomes for the simultaneous loading of the caffeine and anthocyanin, as well as their possible application in food and beverage formulations.

Review of fish protein hydrolysates: production methods, antioxidant and antimicrobial activity and nanoencapsulation

Marine products have gained popularity due to their valuable components, especially protein, despite generating significant waste. Protein hydrolysates are widely recognized as the most effective method for transforming these low-value raw materials into high-value products. Fish protein hydrolysate (FPH), sourced from various aquatic wastes such as bones, scales, skin, and others, is rich in protein for value-added products. However, the hydrophobic peptides have limitations like an unpleasant taste and high solubility. Microencapsulation techniques provide a scientific approach to address these limitations and safeguard bioactive peptides. This review examines current research on FPH production methods and their antioxidant and antibacterial activities. Enzymatic hydrolysis using commercial enzymes is identified as the optimal method, and the antioxidant and antibacterial properties of FPH are substantiated. Microencapsulation using nanoliposomes effectively extends the inhibitory activity and enhances antioxidant and antibacterial capacities. Nevertheless, more research is needed to mitigate the bitter taste associated with FPH and enhance sensory attributes.

Protection of osteogenic peptides in nanoliposomes: Stability, sustained release, bioaccessibility and influence on bioactive properties

This study prepared osteogenic peptides (OPs) from cod meat by hydrolysis and subsequently encapsulated them in nanoliposomes (NLP) to enhance bioaccessibility. The characterization, stability, controlled release behavior and bioactivity of OPs-loaded nanoliposomes (OPs-NLP) were investigated as well. The highest loading capacity (27.32%) was achieved in NLP loaded with 6 mg/mL of OPs. The particle size, zeta potential, and encapsulation efficiency of OPs-NLP were 70.59 nm, -11.98 mV, and 75.24%, respectively. The interaction between OPs and empty NLP was through hydrogen bonding and hydrophobic. The OPs-NLP showed the greatest stability during storage at 4 °C. The in vitro release profile of OPs from OPs-NLP fitted a one-level kinetic model best. The osteogenic activity of OPs was unaffected by NLP encapsulation, and the bioaccessibility of OPs was notably improved. These findings suggest that OPs-NLP has the potential to be used in functional foods.

Protection of navy-bean bioactive peptides within nanoliposomes: morphological, structural and biological changes

This study aimed to produce bioactive peptides from navy-bean protein with alcalase and pepsin enzymes (30-300 min) and to load them into a nanoliposome system to stabilize and improve their bioavailability. The degree of hydrolysis and biological activities (scavenging of DPPH, OH, and ABTS free radicals, reducing power, and chelating metal ions) of navy-bean protein were affected by the type of enzyme and hydrolysis time. The average particle size (83-116 nm), PDI (0.23-0.39), zeta potential (- 13 to - 20 mV), and encapsulation efficiency (80-91%) of nanoliposomes were influenced by the type and charge of peptides. The storage temperature and the type of loaded peptide greatly affected the physical stability of nanocarriers and maintaining EE during storage. The FTIR results suggested the effect of enzymatic hydrolysis on the secondary structures of protein and the effective placement of peptides inside polar-regions and the phospholipid monolayer membrane. SEM images showed relatively uniform-sized particles with irregular structures, which confirmed the results of DLS. The antioxidant activity of primary peptides affected the free radical scavenging of loaded nanoliposomes. Liposomes loaded with navy-bean peptides can be used as a health-giving formula in enriching all kinds of drinks, desserts, confectionery products, etc.

Physicochemical properties and in vitro digestion behavior of emulsion gels stabilized by rice bran protein aggregates: Effects of heating time and induction methods

To investigate the effects of heating time and induction methods on the physicochemical properties and in vitro digestion behavior of emulsion gels, rice bran protein aggregates (RBPAs) were formed by acid-heat induction (90 °C, pH 2.0) and the emulsion gels were further prepared by adding GDL or/and laccase for single/double cross-linked induction. Heating time affected the aggregation and oil/water interfacial adsorption behavior of RBPAs. Suitable heating (1-6 h) was conducive to faster and more adsorption of aggregates at the oil/water interface. While excessive heating (7-10 h) resulted in protein precipitation, which inhibited the adsorption at the oil/water interface. The heating time at 2, 4, 5 and 6 h was thus chosen to prepare the subsequent emulsion gels. Compared with the single cross-linked emulsion gels, the double-cross-linked emulsion gels showed higher water holding capacity (WHC). After simulated gastrointestinal digestion, the single/double cross-linked emulsion gels all exhibited slow-release effect on free fatty acid (FFA). Moreover, the WHC and final FFA release rate of emulsion gels were closely related to the surface hydrophobicity, molecular flexibility, sulfhydryl, disulfide bond and interface behavior of RBPAs. Generally, these findings proved the potential of emulsion gels in designing fat alternatives, which could provide a novel technique for the fabrication of low-fat food.

Functional and structural properties of gliadin as influenced by pH, extraction protocols, and wheat cultivars

Gliadin, owing to its low cost, ease to extract, high foaming capacity, easily available and high surface hydrophobicity, has found a wide range of applications both in the food and pharmaceutical sectors. The functional and structural characteristics of gliadin extracted with four extraction protocols from six wheat cultivars were investigated in this study. The surface-active properties of gliadin protein as a function of pH, extraction protocols, and wheat cultivars were compared, including solubility, zeta-potential, foaming properties, emulsion properties, surface hydrophobicity and secondary structure. Overall gliadin extracted using different extraction protocols and from different wheat cultivars was found to be higher in β-turns (24.88-37.91 %), followed by β-sheet (12.81-22.37 %), α-helix (15.13-20.70 %) and lower in random coil (6.53-9.08 %). Varied pH ranges, wheat cultivars, and different extraction protocols were found to have a substantial impact on solubility, zeta potential, foaming stability, emulsion capacity and surface hydrophobicity. The foaming capacity was observed to be more influenced by extraction protocols than wheat cultivars. Emulsion stability showed statistically significant (p ≤ 0.05) influence between the wheat cultivars, and a non-significant (p ≥ 0.05) difference among extraction protocols. The functional properties of freeze-dried gliadin extracted using different protocols were found to be pH-dependent. A comprehensive understanding of how the structural, surface active and functional properties of gliadin are influenced by the extraction protocols and wheat cultivars will enable us to understand the gliadin better and broaden its use for both food and non-food applications.

Effect of Liposomal Encapsulation and Ultrasonication on Debittering of Protein Hydrolysate and Plastein from Salmon Frame

The impacts of liposomal encapsulation on the bitterness of salmon frame protein hydrolysate (SFPH) and salmon frame protein plastein (SFPP) with the aid of ultrasound (20% amplitude, 750 W) for different time intervals (30, 60 and 120 s) were investigated. Liposomes loaded with 1% protein hydrolysate (L-PH1) and 1% plastein (L-PT1) showed the highest encapsulation efficiency and the least bitterness (p < 0.05). Ultrasonication for longer times reduced encapsulation efficiency (EE) and increased bitterness of both L-PH1 and L-PT1 along with a reduction in particle size. When comparing between L-PH1 and L-PT1, the latter showed less bitterness due to the lower bitterness in nature and higher entrapment of plastein in the liposomes. In vitro release studies also showed the delayed release of peptides from L-PT1 in comparison to the control plastein hydrolysate. Therefore, encapsulation of liposomes with 1% plastein could be an efficient delivery system for improving the sensory characteristics by lowering the bitterness of protein hydrolysates.

Liposome System for Encapsulation of Spirulina platensis Protein Hydrolysates: Controlled-Release in Simulated Gastrointestinal Conditions, Structural and Functional Properties

This study aimed to evaluate the physicochemical, structural, antioxidant and antibacterial properties of chitosan-coated (0.5 and 1% CH) nanoliposomes containing hydrolyzed protein of Spirulina platensis and its stability in simulated gastric and intestine fluids. The chitosan coating of nanoliposomes containing Spirulina platensis hydrolyzed proteins increased their size and zeta potential. The fourier transform infrared spectroscopy (FT-IR) test showed an effective interaction between the hydrolyzed protein, the nanoliposome, and the chitosan coating. Increasing the concentration of hydrolyzed protein and the percentage of chitosan coating neutralized the decreasing effect of microencapsulation on the antioxidant activity of peptides. Chitosan coating (1%) resulted in improved stability of size, zeta potential, and poly dispersity index (PDI) of nanoliposomes, and lowered the release of the hydrolyzed Spirulina platensis protein from nanoliposomes. Increasing the percentage of chitosan coating neutralized the decrease in antibacterial properties of nanoliposomes containing hydrolyzed proteins. This study showed that 1% chitosan-coated nanoliposomes can protect Spirulina platensis hydrolyzed proteins and maintain their antioxidant and antibacterial activities.

Walnut peptide loaded proliposomes with hydroxyapatite as a carrier: Fabrication, environmental stability, and in vitro digestion attribute

To explore the feasibility of hydroxyapatite (HAP) as the carrier for proliposomes and improve the stability of walnut peptides (WPs), WPs-loaded proliposomes (WPs-PROLIPs) with hydroxyapatite (HAP) as the carrier were fabricated, and the physicochemical properties, environmental stability as well as in vitro simulated digestion release performance of the proliposomes were investigated. The proliposomes with HAP possessed smaller particle sizes and higher encapsulation efficiencies than those without HAP. FTIR analysis revealed that hydrogen bonds formed between HAP and phospholipids in the proliposomes. The inclusion of HAP in WPs-PROLIPs led to the improvement of the thermal degradation stability and environmental stabilities of the system. HAP also induced the conversion of free water into bound water in the proliposomes, as evaluated by LF NMR. In addition, proliposomal encapsulation did not affect the antioxidant activity of WPs-PROLIPs and the lateral order of the liposome membrane. Finally, in vitro digestion showed that the addition of HAP endowed the proliposomes with a retarded free fatty acid release effect, which was dependent on the weight ratio of phospholipids to HAP. These results offer opportunities for the use of HAP as a feasible carrier and lyoprotectant for proliposomes encapsulating biopeptides.

Effects of Collagen Hydrolysate From Large Hybrid Sturgeon on Mitigating Ultraviolet B-Induced Photodamage

Ultraviolet B (UVB) radiation leads to the excessive accumulation of reactive oxygen species (ROS), which subsequently promote inflammation, degradation of the extracellular matrix, and photoaging in skin. Thus antioxidant activity is particularly important when screening for active substances to prevent or repair photodamage. Marine fish-derived bioactive peptides have become a trend in cosmetics and functional food industries owing to their potential dermatological benefits. In this study, 1-diphenyl- 2-pycryl-hydrazyl (DPPH) scavenging activity was selected to optimize the hydrolysis conditions of sturgeon skin collagen peptides with antioxidant activity. The optimal hydrolysis conditions for sturgeon skin collagen hydrolysate (SSCH) were determined by response surface methodology, which comprised an enzyme dosage of flavorzyme at 6,068.4 U/g, temperature of 35.5°C, pH of 7, and hydrolysis time of 6 h. SSCH showed good radical-scavenging capacities with a DPPH scavenging efficiency of 95%. Then, the effect of low-molecular-weight SSCH fraction (SSCH-L) on UVB irradiation-induced photodamage was evaluated in mouse fibroblast L929 cells and zebrafish. SSCH-L reduced intracellular ROS levels and the malondialdehyde content, thereby alleviating the oxidative damage caused by UVB radiation. Moreover SSCH-L inhibited the mRNA expression of genes encoding the pro-inflammatory cytokines IL-1β, IL-6, TNF-α, and Cox-2. SSCH-L treatment further increased the collagen Ⅰα1 content and had a significant inhibitory effect on matrix metalloproteinase expression. The phosphorylation level of JNK and the expression of c-Jun protein were significantly reduced by SSCH-L. Additionally, SSCH-L increased the tail fin area at 0.125 and 0.25 mg/ml in a zebrafish UVB radiation model, which highlighted the potential of SSCH-L to repair UVB-irradiated zebrafish skin damage. Peptide sequences of SSCH-L were identified by liquid chromatography-tandem mass spectrometry. Based on the 3D-QSAR modeling prediction, six total peptides were selected to test the UVB-protective activity. Among these peptides, DPFRHY showed good UVB-repair activity, ROS-scavenging activity, DNA damage-protective activity and apoptosis inhibition activity. These results suggested that DPFRHY has potential applications as a natural anti-photodamage material in cosmetic and functional food industries.

Encapsulation of Salmon Peptides in Marine Liposomes: Physico-Chemical Properties, Antiradical Activities and Biocompatibility Assays

Salmon byproducts (Salmo salar) generated by the food chain represent a source of long-chain polyunsaturated fatty acids (eicosapentaenoic acid (EPA): 20:5n-3; docosahexaenoic acid (DHA): 22:6n-3) and peptides that can be used as supplements in food for nutraceutical or health applications, such as in the prevention of certain pathologies (e.g., Alzheimer’s and cardiovascular diseases). The extraction of polar lipids naturally rich in PUFAs by enzymatic processes without organic solvent (controlled by pH-Stat method), coupled with the production of 1 kDa salmon peptides by membrane filtration, allowed the formulation of nanocarriers. The physicochemical properties of the nanoliposomes (size ranging from 120 to 140 nm, PDI of 0.27, zeta potential between −32 and −46 mV and encapsulation efficiency) were measured, and the bioactivity of salmon hydrolysate peptides was assessed (antioxidant and antiradical activity: ABTS, ORAC, DPPH; iron metal chelation). Salmon peptides exhibited good angiotensin-conversion-enzyme (ACE) inhibition activity, with an IC₅₀ value of 413.43 ± 13.12 µg/mL. Cytotoxicity, metabolic activity and proliferation experiments demonstrated the harmlessness of the nanostructures in these experimental conditions.

Nanoencapsulated Lippia rotundifolia antimicrobial peptide: synthesis, characterization, antimicrobial activity, and cytotoxicity evaluations

Antimicrobial peptides (AMP) are promising novel antibiotics but exhibit low stability and can be toxic. The AMP encapsulation can be used to protect the drug and control its release rates. The Lr-AMP1f encapsulated into chitosan nanoparticle (NP) by ionic gelation method reached 90% efficiency. The results indicated that the hydrodynamic particle size of NPs increased from 196.1 ± 3.14 nm (free NP) to 228.1 ± 12.22 nm (nanoencapsulated Lr-AMP1f), while the atomic force microscope showed the spherical shape. The Zeta potential of the nanoencapsulated Lr-AMP1f was high (+ 35 mV). These AMP-loaded NPs exhibited stability for up to 21 days of storage. The minimum inhibitory concentration (MIC) of free Lr-AMP1f was 8 µg/mL for E. coli and S. epidermidis. However, the nanoencapsulated Lr-AMP1f produced a bacteriostatic effect against both bacteria at 8 µg/mL. The MIC of nanoencapsulated Lr-AMP1f was 16 µg/mL for E. coli and 32 for S. epidermidis. Nanoencapsulated Lr-AMP1f was nontoxic to HEK293 cells. Promisingly, chitosan NP can be used as a vehicle for the antibacterial application of new AMP (Lr-AMP1f).

Preparation, characterization and stability of nanoliposomes loaded with peptides from defatted walnut (Juglans regia L.) meal

This study aimed to encapsulate walnut peptides with different molecular weights (crude peptides, 5-10 kDa and < 5 kDa) within nanoliposomes. The peptides with molecular weight (MW) of 5-10 kDa (F2) was chosen as a representative sample to indicate the formation mechanism of nanoliposomes using scanning electron microscopy (SEM) and transmission electron microscope (TEM). The storage and simulated digestion experiment were carried out to evaluate the protective effect of nanoliposomes loading walnut peptides. Our results indicated that the amino acid composition was affected by peptide MW, and F2 exhibited the highest content of hydrophobic amino acids content. The MW of peptides also affected the distribution of the peptide of nanoliposomes, resulting in changes in particle size, ζ-potential, and encapsulation efficiency. The SEM exhibited that a high concentration of nanoliposomes might result in phospholipid fusion and larger particle diameters. The TEM showed individual nanoliposomes had spherical, smooth and full vesicle structures. The nanoliposomes could improve the stability of walnut peptides during storage. The maximum peptides retention after in vitro digestion was 61.6%, indicating a better sustained release in gastric digestion. The present study suggested that nanoliposomes can offer adequate protection to the walnut peptides during storage and digestion.

Comparative evaluation of gliadins from four extraction protocols using advanced analytical techniques

Gliadin, a major component of gluten, is known to trigger celiac disease; therefore, its extraction is important to study its properties as well as its presence in gluten-free products. Four gliadin extraction procedures Osborne (1924), Weiss (1993), Wallace (1989) and DuPont (2005), were investigated on six wheat cultivars using advanced analytical techniques such as dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Higher zeta potential of extracted gliadin was observed in DuPont (23.53-27), followed by Weiss (16.17-20.80), Osborne (16.17-20.13), and Wallace (14.60-19.47). Particle Z-average size (15.74-184.83 nm) was found to have an inverse relationship with the Polydispersity index (0.17-184.83). The surface morphological structure of TEM studies revealed the compact globular particle arrangement of gliadin, besides rod-shaped arrangement, was also found in DuPont and Wallace extracted gliadin. XRD pattern of gliadin exposed the crystalline domain at 44.1°, 37.8°, and 10.4° diffraction peaks. The d-spacing obtained from XRD and TEM-SAED analysis supports the presence of crystalline domains in gliadin apart from the amorphous domain. The insight obtained from this work will provide a better understanding of morphology and other properties of the same protein extracted with different extraction procedures.

Bioactivity of the Protein Hydrolysates Obtained from the Most Abundant Crustacean Bycatch

The animals from bycatch of the shrimp fisheries can be a source of natural products and bioactive compounds. Thus, the present study aimed to evaluate the bioactivity of protein hydrolysates prepared from the two most abundant crabs from the bycatch of shrimp fisheries in Brazil (Callinectes ornatus and Hepatus pudibundus). Samples of C. ornatus and H. pudibundus were collected in the region of Ubatuba, State of São Paulo, Brazil. Muscles with small pieces of exoskeleton of both species were hydrolyzed using two enzymes, Alcalase 2.4 L® or Protamex®. The in vitro antioxidant capacity was analyzed used three methods: DPPH, sulfhydryl groups, and peroxyl radicals. Additionally, the cytotoxicity of the hydrolysates was investigated using pre-osteoblasts cells. The results showed that the degree of hydrolysis (DH) of H. pudibundus was superior to DH of C. ornatus using both enzymes and was higher when using the enzyme Alcalase 2.4 L® (32.0% ± 1.9). The analysis suggested that the hydrolysates have antioxidant activity. Besides that, no cytotoxic effect was observed on cell viability. Thus, protein hydrolysates of C. ornatus and H. pudibundus have bioactivity, which add value to these bycatch species and suggests their potential use as nutraceutical ingredient in the food industry.

Characterization of gliadin, secalin and hordein fractions using analytical techniques

Prolamins, alcohol soluble storage proteins of the Triticeae tribe of Gramineae family, are known as gliadin, secalin and hordein in wheat, rye and barley respectively. Prolamins were extracted from fifteen cultivars using DuPont protocol to study their physiochemical, morphological and structural characteristics. SDS-PAGE of prolamins showed well resolved low molecular weight proteins with significant amount of albumin and globulin as cross-contaminant. The β-sheet (32.72–37.41%) and β-turn (30.36–37.91%) were found higher in gliadins, while α-helix (20.32–28.95%) and random coil (9.05–10.28%) in hordeins. The high colloidal stability as depicted by zeta-potential was observed in gliadins (23.5–27.0 mV) followed secalins (11.2–16.6 mV) and hordeins (4.1–7.8 mV). Surface morphology by SEM illustrated the globular particle arrangement in gliadins, sheet like arrangement in secalins and stacked flaky particle arrangement in hordeins fraction. TEM studies showed that secalin and hordein fractions were globular in shape while gliadins in addition to globular structure also possessed rod-shaped particle arrangement. XRD pattern of prolamin fractions showed the ordered crystalline domain at 2θ values of 44.1°, 37.8° and 10.4°. The extracted prolamins fractions showed amorphous as well as crystalline structures as revealed by XRD and TEM analysis. Space saving hexagonal molecular symmetry was also observed in TEM molecular arrangement of prolamins which has profound application in development of plant-based polymers and fibres.

Dietary effects of a low-molecular weight fraction (<10 kDa) from shrimp waste hydrolysate on growth performance and immunity of rainbow trout (Oncorhynchus mykiss): Employing nanodelivery systems

Aquaculture by-products have been of great interest for producing protein hydrolysates with multiple biological activities. The present experiment was carried out to evaluate dietary effects of a low-molecular fraction (<10 kDa) from shrimp waste hydrolysate in forms of unprotected and nanocapsulated on growth and immunity of rainbow trout. Therefore, six diets were designed including a control diet (no supplementation), D1 (1 g kg^-1 of unprotected fraction), D2 (1 g kg^-1 chitosan nanocapsules), D3 (1 g kg^-1 liposome nanocapsules), D4 (1 g kg^-1 of fraction-loaded chitosan nanocapsules), D5 (1 g kg^-1 of fraction-loaded liposome nanocapsules). Fish (0.91 ± 0.15 g) were fed with experimental diets until apparent satiation for six weeks followed by a 5-day experimental challenge with Streptococcus iniae. Results revealed that growth is strongly affected in fish receiving the fraction with D4 treatment showing the highest weight gain, SGR, final weight and the lowest FCR (p < 0.05). Nanocapsules without fraction did not show remarkable effects when compared to control group. In terms of serum and mucus immune parameters of lysozyme, complement activity, myeloperoxidase activity, and total protease, fish from D4 group showed the highest measured values followed by D5 (p < 0.05). Key immune related genes of IL-6 and TNF-α were noticeably up-regulated in fish from D1, D4, and D5 groups, which were consistent with survival rate after 5 days challenge with Streptococcus iniae. All together, the present findings highlighted the application of chitosan and liposome nanocarriers in aquaculture and potential of low-molecular weight fraction (<10 kDa) from shrimp wastes hydrolysate to improve growth performance and immune status of rainbow trout.

Elucidating the Calcium-Binding Site, Absorption Activities, and Thermal Stability of Egg White Peptide-Calcium Chelate

With the current study, we aimed to determine the characteristics and calcium absorption capacity of egg white peptide-calcium complex (EWP-Ca) and determine the effect of sterilization on EWP-Ca to study the possibility of EWP-Ca as a new potential calcium supplement. The results of SEM and EDS showed a high calcium chelating ability between EWP and calcium, and the structure of EWP-Ca was clustered spherical particles due its combination with calcium. The FTIR and Raman spectrum results showed that EWP could chelate with calcium by carboxyl, phosphate, and amino groups, and peptide bonds may also participate in peptide-calcium binding. Moreover, the calcium absorption of EWP-Ca measured by the intestinal everted sac model in rats was 32.38 ± 6.83 μg/mL, significantly higher than the sample with CaCl2, and the mixture of EWP and Ca (p < 0.05) revealed appropriate calcium absorption capacity. The fluorescence spectra and CD spectra showed that sterilization caused a decrease in the content of α-helix and β-sheet and a significant increase in β-turn (p < 0.05). Sterilization changed the EWP-Ca structure and decreased its stability; the calcium-binding capacity of EWP-Ca after sterilization was decreased to 41.19% (p < 0.05). Overall, these findings showed that EWP could bind with calcium, form a peptide-calcium chelate, and serve as novel carriers for calcium supplements.

Fabrication and characterization of walnut peptides-loaded proliposomes with three lyoprotectants: Environmental stabilities and antioxidant/antibacterial activities

To protect walnut peptides from harsh external environments during their storage and digestion, proliposomes loaded with walnut peptides were fabricated using sucrose, trehalose, and mannitol as carriers and lyoprotectants. The physicochemical properties, environmental stability, antioxidant/antibacterial activities, and digestion in vitro of the proliposomes were evaluated. The freshly prepared liposomes were uniform in size, but the hydrated proliposomes showed a more uneven size distribution. The lyoprotectants helped maintain favorable liposome shape during lyophilization. Alongside the lyoprotectants, the walnut peptides further stabilized the lipid bilayer. Proliposomes encapsulation didn't impact the peptides' antioxidant activity. Furthermore, walnut peptides-loaded proliposomes exhibited antibacterial activity against Escherichia coli and Staphylococcus aureus. The proliposomes were stable during gastric-phase digestion. The lyoprotectants changed the free fatty acid release behaviors of the proliposomes. These characteristics suggest potential applications for proliposomes as effective delivery systems for biopeptides in food stuffs, thereby protecting bioactivities during storage and passage through the gastrointestinal tract.

Nanoliposomes for encapsulation and calcium delivery of egg white peptide-calcium complex

Nanoliposomes and crude liposomes loaded with egg white peptide-calcium complex (EWP-Ca) were fabricated by thin-film dispersion with or without dynamic high-pressure microfluidization. Their physiochemical properties, in vitro stability, and calcium release profiles were investigated in this study. Results showed that the EWP-Ca-loaded nanoliposomes exhibited spherical structures with a lower particle size and polydispersity index as well as a higher thermal stability as compared to the corresponding crude liposomes. Further investigations revealed that EWP-Ca was embedded into the liposomes mainly through hydrogen bonding and present in an amorphous form within the liposomes. Additionally, the EWP-Ca-loaded nanoliposomes effectively slowed the release of calcium in gastric digestion, allowing more soluble calcium to enter the intestinal tract; in the subsequent intestinal digestion, the EWP-Ca-loaded nanoliposomes were more electrically and physically stable than the crude liposomes. Therefore, the EWP-Ca-loaded nanoliposomes could be used as a favorable dietary calcium delivery system to promote calcium bioavailability. PRACTICAL APPLICATION: Nanoliposomes were fabricated in this study to encapsulate the egg white peptide-calcium complex (EWP-Ca) for calcium delivery. The EWP-Ca-loaded nanoliposomes effectively slowed the release of calcium in gastric digestion, allowing more soluble calcium to enter the intestinal tract, and were more electrically and physically stable in the subsequent intestinal digestion. Therefore, the EWP-Ca-loaded nanoliposomes may be incorporated in calcium-fortified food to enhance calcium delivery for maintaining bone health.

Preparation and Characterization of Microcapsules Containing Antioxidant Fish Protein Hydrolysates: a New Use of Bycatch in Brazil

In this study, we evaluated the effect of complexation and microencapsulation with pea protein on the antioxidant activity of protein hydrolysates from bycatch in Brazil. The zeta potential values of complexes changed from negative to positive with the increase of pea protein as a result of positively charged complexes formation. The increase in the ratio of pea protein/hydrolysates also resulted in increased turbidity in all samples. Particle size measurements indicated that the complexes tended to form larger aggregates (ranged from 61.5 ± 1.7 μm to 183 ± 2.8 μm). The 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity of the pea protein/fish protein hydrolysate complexes was higher than that of the protein hydrolysates alone. Moreover, increasing levels of pea protein did not affect the antioxidant activity of fish protein hydrolysates. The complexes of the Paralonchurus brasiliensis were chosen for the microencapsulation process by spray-drying. The results revealed that spray-drying did not have a significant effect (P > 0.05) on the protein hydrolysate antioxidant activity when they were complexed with pea protein. Thus, this work suggests that the complexation with pea protein and subsequent microencapsulation by spray-drying is an efficient way to protect the biological activity of protein hydrolysates obtained from bycatch. This study provides evidence for the potential use of bycatch from shrimp fisheries as functional ingredients or nutraceuticals.

Functional foods and bioactive ingredients harnessed from the ocean: current status and future perspectives

With an increase in life expectancy and decrease of quality-of-life couple with the high prevalence of diseases, diet is expected to play a key function in sustaining human health. Nutritionists, food technologists and medical experts are working in synergy to cater for the increasing demand of food with associated therapeutic benefits, commonly known as functional food, that may improve well-being and reduce the risk of diseases. Interestingly, the marine ecosystem, due to its abundant and phenomenal biodiversity of marine organisms, constitutes a vital source of a panoply of healthy foods supply for the thriving functional food industry. Marine organisms such as seaweeds, sea cucumbers, sponges, and mollusks amongst others are sources of thousands of biologically active metabolites with antioxidant, anti-parasitic, antiviral, anti-inflammatory and anticancer properties. Given the growing number of research and interest to probe into the therapeutic roles of marine products, this review was designed to provide a comprehensive summary of the therapeutic properties of marine organisms (macroalgae, sea cucumbers and fish among others) which are consumed worldwide, in addition to their potentials and as sources of functional ingredients for developing novel food and fostering wellness. The gap between research development and actual commercialization, and future prospects of marine-based products also summarized to some extent.

Encapsulation of oyster protein hydrolysates in nanoliposomes: Vesicle characteristics, storage stability, in vitro release, and gastrointestinal digestion

In this study, oyster protein hydrolysates (OPH) were obtained from oyster meat by hydrolysis using animal complex proteases and then encapsulated in nanoliposomes. The physicochemical properties, stability, and digestive characteristics of OPH-loaded nanoliposomes were evaluated. The average size and zeta potential ranged from 95.64 to 102.39 nm and from -47.36 to -36.43 mV, respectively. Liposomes containing 4 mg/mL OPH had the highest encapsulation efficiency (74.53%). Fourier transform infrared spectroscopy analysis showed that effective ionic complexation and hydrogen bonding existed between phospholipid and peptides. The liposomes exhibited the highest stability when stored at 4 °C. Liposomal encapsulation may protect the antioxidant peptides in OPH during storage and simulated digestion. The nanoliposomes were not hydrolyzed and the structural integrity was maintained in gastric digestion, but exhibited lower stability in the intestinal phase. A prolonged release of OPH from nanoliposomes was also observed as compared with free OPH. Liposome containing protein hydrolysates may be used as a formula in functional foods. PRACTICAL APPLICATION: This study provides some useful information on the application of oyster protein hydrolysates or peptides in functional foods. The incorporation into liposomes may protect the hydrolysates against harsh conditions during storage and digestion, and also prolong the release time.

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.

Peptidases from Maclura Pomifera for Preparation of Food Protein Hydrolysates: Purification by Single-Step Chromatography and Characterization of Pomiferin I

Our objective was to isolate peptidases from the latex of Maclura pomifera fruits and use them to hydrolyze food proteins, as well as to purify and characterize the main peptidase. Two partially purified proteolytic extracts were prepared by ethanol (EE) and acetone (AE) precipitation from an aqueous suspension of exuded fruit latex. EE was used to hydrolyze food proteins with a ratio of 0.19 caseinolytic units (Ucas) per mg of substrate. Different values of hydrolysis degree were observed for hydrolysates of egg white, soy protein isolate, and casein at 180 min (9.3%, 31.1%, and 29.1%, respectively). AE was employed to purify a peptidase which exhibited an isoelectric point (pI) of 8.70 and whose abundance in AE was 28.3%. This enzyme was purified to homogeneity using a single-step procedure by cation-exchange chromatography, achieving an 8.1-fold purification and a yield of 16.7%. The peptidase was named pomiferin I and showed a molecular mass of 63,177.77 Da. Kinetic constants (K_M 0.84 mM, V_max 27.50 uM s^-1, k_cat 72.37 s^-1, and k_cat/K_M 86.15 mM^-1 s^-1) were determined employing N-α-carbobenzoxy-L-alanyl-p-nitrophenyl ester as substrate. Analysis by PMF showed only partial homology of pomiferin I with a serine peptidase from a species of the same family.

Effect of nanoliposomal entrapment on antioxidative hydrolysates from goose blood protein

In this study, the encapsulation of goose blood hydrolysate (GBH) was performed within nanoliposomes. We investigated the physicochemical properties, stability, antioxidant indices, the morphology of nanoparticles, the digestion stability in simulated gastrointestinal fluid, differential scanning calorimetry (DSC) analysis, and Fourier transform infrared (FTIR) spectroscopy. GBH was successfully encapsulated into nanoliposomes using reverse-phase evaporation method. The entrapment efficiency of GBH-loaded nanoliposomes was about 70.99 ± 2.85%, the average particle size was 93.3 ± 2.45 nm, the zeta-potential of GBH-loaded nanoliposomes was -30 mV, and the morphology of GBH-loaded nanoliposomes was characterized by transmission electron microscope. Moreover, the results of DSC and FTIR showed that the GBH nanoliposome was more stable than the empty liposomes due to hydrogen bond complexation between liposome and GBH. The release of GBH from nanoliposomes could be significantly controlled, and the release ratios were 48.9 ± 2.96% in simulated gastric fluid and 59.9 ± 5.30% in simulated intestinal fluid, respectively, proving that degradation rate of antioxidant activities of GBH encapsulated in nanoliposomes was decreased. In conclusion, nanoliposomes embedding is a promising and effective way to increase the stability of hydrolysates from GBH and produce various types of functional food.

Effects of partial hydrolysis on the structural, functional and antioxidant properties of oat protein isolate

The degree of hydrolysis (DH) plays important roles in the characteristics of food proteins. Herein, in order to explore the effects of partial hydrolysis on the structural, functional and antioxidant characteristics of hydrolysates, oat protein isolate was partially hydrolyzed with alcalase at different DHs (2%, 4%, 6%, 8%, 12%, and 16%). Our results showed that hydrolysis could induce significant structural changes in oat protein, mainly reflecting at the amino acid pattern, molecular weight profile and protein conformation. Alcalase hydrolysis also resulted in hydrolysates with the emulsifying activity index of at least 19.83 m2 g-1, and the highest emulsion stability was observed in the hydrolysate with a DH of 6%, possibly due to its suitable molecular weight, exposed hydrophobic amino acid residues and high surface net charge. Besides, all hydrolysates exerted excellent DPPH radical scavenging activity with an IC50 value ranging from 19.23 to 30.32 μg mL-1, which was closely correlated with DH. The oat protein isolate with moderate alcalase hydrolysis (DH 6%) exhibited the strongest metal ion-chelating activity and possessed the maximum amount of hydrophilic amino acids. More importantly, the oat protein hydrolysate with a DH of 6% not only prolonged the induction period of sunflower oil, but also improved the stability of the sunflower oil-in-water emulsion, as evidenced by the reduced TBARS production and the homogeneous droplet size. Therefore, partial hydrolysis can be advantageous for improving the functional and antioxidant characteristics of oat protein isolate, particularly the hydrolysate with a DH of 6%.

Comparative assessment of physicochemical and antioxidative properties of mung bean protein hydrolysates

Two commercial plant proteases namely ficin and bromelain, were acquired to hydrolyze mung bean protein over 300 min hydrolysis, and the physicochemical and antioxidative properties of the obtained hydrolysates were investigated. Bromelain-treated mung bean protein hydrolysates presented a higher degree of hydrolysis in comparison with ficin-treated hydrolysates, further modifying their physicochemical and emulsifying properties. All mung bean protein hydrolysates exhibited 50% scavenging of DPPH radical (IC50) in the concentration range from 8.67 to 16.22 μg mL-1. Our results also showed that strong metal ion-chelating activity was found in the ficin- (higher activity) and bromelain-treated protein hydrolysates. In addition, oxidative stability of linoleic acid was significantly enhanced by two selected protein hydrolysates, particularly the bromelain-treated hydrolysate with the highest inhibition effect of linoleic acid oxidation (94.55 ± 0.10%). Interestingly, both of these two hydrolysates could effectively retard lipid oxidation of sunflower oil and sunflower oil-in-water emulsion, while the ficin-treated hydrolysate showed slightly better performance. Therefore, mung bean protein hydrolysates showed potential to inhibit lipid oxidation, which could be advantageous in the food industry for producing fortified food.

Furcellaran-Coated Microcapsules as Carriers of Cyprinus carpio Skin-Derived Antioxidant Hydrolysate: An In Vitro and In Vivo Study

Carp skin gelatine hydrolysate (CSGH) may be a possible bioactive peptide source, as promising antioxidant properties have been noted during in vivo testing. Hence, the present study focused on improving the bioavailability of the antioxidant peptides from CSGH and on the use of furcellaran (FUR), which can protect the biopeptides during digestion in the gastrointestinal tract. Therefore, in this study, microcapsules coated with furcellaran and containing CSGH cores were prepared. The structural properties of the sample were determined using FT-IR and SEM analysis. The antioxidant properties of hydrolysate, uncoated, and encapsulated samples were investigated. In vivo analysis included determination of its safety in an animal organism and evaluation of the lipid profile, antioxidant blood status, and mRNA expression of some genes involved in antioxidant status in Wistar rats. The results showed no adverse effects of microencapsulated protein hydrolysates in laboratory animals. Nonetheless, there was a statistically significant rise in the level of total antioxidant status blood serum among animals consuming CSGH and not inducing oxidative stress. This can be viewed as a promising indication of the positive effects of antioxidant properties tested in vivo. The process of CSGH microencapsulation in FUR cause a decrease in antioxidant hydrolysate activity, both in vitro, as well as in healthy Wistar rats. When considering the results of the presented diverse therapeutic potential, further research on CSGH being a potential bioactive peptide source used as a functional food or nutraceutical, but with a different microencapsulation coating, is encouraged.