Multiple Pickering emulsions stabilized by food-grade particles as innovative delivery systems for bioactive compounds.

The most common carrier for encapsulation of bioactive components is still simple emulsion. Recently, bio-based novel emulsion systems such as multiple emulsions (MEs) and Pickering emulsions (PEs) have been introduced as innovative colloidal delivery systems for encapsulation and controlled release of bioactive compounds. Multiple PEs (MPEs), which carries both benefit of MEs and PEs could be fabricated by relatively scalable and simple operations. In comparison with costly synthetic surfactants and inorganic particles which are widely used for stabilization of both MEs and PEs, MPEs stabilized by food-grade particles, while having health-promoting aspects, are able to host the "clean label" and "green label" attributes. Nevertheless, in achieving qualified techno-functional attributes and encapsulation properties, the selection of suitable materials is a crucial step in the construction of such complex systems. Current review takes a cue from both MEs and PEs emulsification techniques to grant a robust background for designing various MPEs. Herein, various fabrication methods of MEs and PEs are described comprehensively in a physical viewpoint in order to find key conception of successful formulation of MPEs. This review also highlights the link between the underlying aspects and exemplified specimens of evidence which grant insights into the rational design of MPEs through food-based ingredients to introduces MPEs as novel colloidal/functional materials. Their utilization for encapsulation of bioactive compounds is discussed as well. In the last part, instability behavior of MPEs under various conditions will be discussed. In sum, this review aims to gain researchers who work with food-based components, basics of innovative design of MPEs.

Gut Microbiota and Polycystic Ovary Syndrome (PCOS): Understanding the Pathogenesis and the Role of Probiotics as a Therapeutic Strategy.

Polycystic ovary syndrome (PCOS) is one of the most common disorders among women in modern societies. A variety of factors can contribute to the development of PCOS. These women often exhibit high insulin resistance (IR), hyperandrogenism, irregular periods, and infertility. Dysbiosis of the gut microbiota (GMB) in women with PCOS has attracted the attention of many researchers. Porphyromonas spp., B. coprophilus, and F. prausnitzii are found in higher numbers in the gut of women with PCOS. Short-chain fatty acids (SCFAs), produced by the intestinal microbiota through fermentation, play an essential role in regulating metabolic activities and are helpful in reducing insulin resistance and improving PCOS symptoms. According to studies, the bacteria producing SCFAs in the gut of these women are less abundant than in healthy women. The effectiveness of using probiotic supplements has been proven to improve the condition of women with PCOS. Daily consumption of probiotics improves dysbiosis of the intestinal microbiome and increases the production of SCFAs.

Technological, nutritional, and biological properties of apricot kernel protein hydrolyzates affected by various commercial proteases.

The effect of enzymatic hydrolysis of apricot kernel protein with different proteases (Alcalase, pancreatin, pepsin, and trypsin) on the amino acid content, degree of hydrolysis (DH), antioxidant, and antibacterial characteristics of the resulting hydrolyzates was investigated in this study. The composition of amino acids (hydrophobic: ~35%; antioxidant: ~13%), EAA/TAA ratio (~34%), and PER index (~1.85) indicates the ability of the hydrolyzate as a source of nutrients and antioxidants with high digestibility. Enzymatic hydrolysis with increasing DH (from 3.1 to a maximum of 37.9%) led to improved solubility (especially in the isoelectric range) and changes in water- and oil-holding capacity. The highest free radical scavenging activity of DPPH (83.3%), ABTS (88.1%), TEAC (2.38 mM), OH (72.5%), NO (65.7%), antioxidant activity in emulsion and formation of TBARS (0.36 mg MDA/L), total antioxidant (1.61), reducing power (1.17), chelation of iron (87.7%), copper (34.8%) ions, and inhibition of the growth of Escherichia coli (16.3 mm) and Bacillus cereus (15.4 mm) were affected by the type of enzymes (especially Alcalase). This research showed that apricot kernel hydrolyzate could serve as a nutrient source, emulsifier, stabilizer, antioxidant, and natural antibacterial agent in functional food formulations.

Structural modification of poppy-pollen protein as a natural antioxidant, emulsifier and carrier in spray-drying of O/W-emulsion: Physicochemical and oxidative stabilization.

This study was aimed to investigate the efficiency of poppy-pollen (PP) protein and peptides as carrier for spray-drying encapsulation of grape-seed oil (GSO). The composition of amino acids, functional properties and bioactivity (scavenging of DPPH, ABTS, OH, and nitric-oxide radicals, reducing power, total antioxidant, TBARS levels in O/W-emulsion, and chelation of Fe2+ and Cu2+ ions) of PP-protein were affected by the enzymolysis time. Partial enzymolysis (30 min) led to improved solubility, protein surface activity and increased physical stability of GSO/W emulsion (relative to creaming, aggregation and flocculation) during storage. Also, spray-dried emulsions with this type of carrier (H-30) had the highest production yield (~67 %), solubility (~92 %), flowability, encapsulation efficiency (~96 %), reconstitution ability (least size and EE changes), physical and oxidative stability. The evaluation of the chemical structures (FTIR) indicated the formation of hydrogen bonds between the cis-alkene groups of fatty acids and the hydroxyl groups of the amide A and B regions, as well as the trapping of oil in the carrier matrix. SEM images illustrated the effect of native protein carriers (particles with smooth, dents, and hollow surfaces with surface pores), partially (wrinkled and reservoir-type), and strongly (irregular structures, sticky and amorphous agglomerates) hydrolyzed peptides on the morphology of oily-particles. The results of this research indicate the usability of partially hydrolyzed poppy-pollen protein as a source of natural antioxidant, emulsifier, and carrier in the production, stabilization, and encapsulation of oxidation-sensitive bioactive components and emulsions.

Biological stabilization of natural pigment-phytochemical from poppy-pollen (Papaver bracteatum) extract: Functional food formulation.

In this study, poppy-pollen extract (as a novel source of pigment and natural phytochemical) was microencapsulated. The spray-drying process maintained the encapsulation efficiency (EE) of phenolic (84-93%), anthocyanins (71-83%), and also antioxidant activity of extract in inhibiting DPPH (68-80%), ABTS (74-95%), OH (63-74%) radicals and reducing power (84-95%). The results of the Photo- and thermal (40-70˚C) stability of the bioactive compounds (TPC and TAC) indicated the thermal degradation and decomposition of particles' surface compounds during storage. The chemical (FTIR) and morphological analyses respectively revealed the insertion of extract compounds in the carrier matrix and the production of healthy particles with wrinkled structures. An increase in the carrier concentration elevated physical-stability, maintained structural properties, reduced hygroscopicity, and formed liquid/solid bridges or deliquescence phenomenon. The evaluation of the color histogram of the fortified gummy-candies indicated the usability of the spray-dried PP extract in producing an attractive red color with high sensory perception.

Physicochemical characteristics and antioxidant stability of spray-dried soy peptide fractions.

The direct addition of health-promoting peptides to food products is limited due to their physicochemical instability and bitter taste as well as their bio-functionality may be influenced by MW. In this study, SPI hydrolysate (SPIH) was Alcalase-prepared, size-fractionated (<10, 10-30, and 30-100 kD), and the amino acid composition of peptide fractions determined. The physicochemical properties, morphology, and antioxidant stability of the fractions were also investigated after spray-drying encapsulation in maltodextrin-WPC carrier. The two low MW peptide fractions (especially, PF < 10) were more active than intact SPI, SPIH, and high MW peptide fraction in scavenging free radicals and chelating transition metal ions. As compared to the particles containing SPIH, those containing the smallest peptide fraction (PF < 10) had higher solubility and hygroscopicity, lower production yield and wettability, and more wrinkles, indentations and surface roughness. The highest antioxidant stability during spray-drying was observed for the two low MW peptide fractions, which examined by scavenging of free radicals of DPPH (88%), ABTS (97%), OH (93%) and NO (80%), chelating of iron (88%) and copper (87-90%) ions, reducing power (93%), and total antioxidant activity (90%). This finding reflects more structural and biological stability of the low MW fractions to shear stress and dehydration during spray-drying, as compared with SPIH. The spray-drying encapsulated soy peptide fractions may be used as nutraceuticals for the development of functional foods.

Nutritional, biological, and structural properties of bioactive peptides from bellflower, Persian-willow, and bitter-orange pollens.

In this study, the composition of amino acids, nutritional characteristics, degree of hydrolysis (DH), antioxidant properties, and antibacterial activity of proteins and hydrolysates of bellflower (Campanula latifolia), Persian willow (Salix aegyptiaca), and bitter orange (Citrus aurantium L.) were investigated under the influence of different proteases (Alcalase: Al, trypsin: Tr, pancreatin: Pa, and pepsin: Pe). Evaluation of the structural features of the proteins showed amide regions (amide A, B, I-III) and secondary structures. Hydrophobic amino acids (∼38%), antioxidants (∼21%), and essential types (∼46%) form a significant part of the structure of flower pollen. The digestibility and nutritional quality (PER) of the hydrolyzed samples (CP: 1.67; CA: 1.89, and PW: 1.93) were more than the original protein. Among proteins and peptides, the highest degree of hydrolysis (34.6%: Al-PWH), inhibition of free radicals DPPH (84.2%: Al-CPH), ABTS (95.2%: Pa-CPH), OH (86.7%: Tr-CAH), NO (57.8%: Al-CPH), reducing power (1.31: Pa-CPH), total antioxidant activity (1.46: Pa-CPH), and chelation of iron ions (80%: Al-CPH and Al-CAH) and copper (50.3%: Pa-CAH) were affected by protein type, enzyme type, and amino acid composition. Also, the highest inhibition of the growth of Escherichia coli (25 mm) and Bacillus cereus (24 mm) were related to CP and PW hydrolysates, respectively. The results of this research showed that hydrolyzed flower pollens can be used as a rich source of essential amino acids as well as natural antioxidants and antibacterial in food and dietary products. PRACTICAL APPLICATION: Enzymatic hydrolysis of Campanula latifolia, Persian willow, and Citrus aurantium pollen proteins was performed. The hydrolyzed ones had high nutritional quality and digestibility (essential amino acids and PER index). Antioxidant properties and chelation of metal ions of peptides were affected by the type of protein and enzyme. The hydrolysates showed inhibitory activity against the growth of Esherichia coli and Bacillus cereus.

The enzymatic modification of whey-proteins for spray drying encapsulation of Ginkgo-biloba extract.

Ginkgo biloba extract (GBLE) contains many bioactives including flavonoids and terpene trilactones that play some pharmacological roles. These compounds are sensitive to operating conditions; so, encapsulation is a suitable approach to protect them. In this study, different carriers including maltodextrin (MD), and its combination with gum-Arabic (MD-GA), whey protein concentrate (MD-WPC), and whey-protein hydrolysate (MD-HWPC) were used to encapsulate GBLE. Powder production yield, physicochemical/functional characteristics, physical stability and flowability of particles were affected by the type and composition of carriers. FTIR results indicated the placement of phenolic compounds in the carrier matrix. The SEM images also showed the morphological changes of particles (especially the size, indentation and surface shrinkage) under the influence of various carriers. Microencapsulated powders formulated using MD-HWPC showed the highest values of TPC, DPPH, and ABTS and a lighter color which determined the suitability of this wall material (due to the improvement of surface activity and emulsifying properties of protein as a result of partial enzymatic hydrolysis) to protect the antioxidant properties of GBLE during spray-drying, improving the production yield and preserving physical and functional characteristics of the encapsulated powders.

Physicochemical, antioxidant, antimicrobial, and in vitro cytotoxic activities of corn pollen protein hydrolysates obtained by different peptidases.

The applications of protein hydrolysates as food preservatives and nutraceutical ingredients have attracted much attention because of their beneficial effects. The interest in these ingredients has shifted toward their biological activities with benefits to human health. Bioactive peptides are known as antioxidant agents that could promote health-promoting effects and prolong food shelf-life beyond their basic nutritional value. Thus, the aim of this study was to investigate antioxidant, antimicrobial, and in vitro cytotoxic properties of corn pollen protein (CPP) hydrolysates obtained by different enzymes. Proteolytic activity in terms of degree of hydrolysis (DH) and SDS-PAGE analysis was measured in pancreatin (H-Pan), pepsin (H-Pep), and trypsin (H-Tri) hydrolysates. Amino acid composition, antioxidant and antimicrobial activities, and cytotoxicity of hydrolysates were evaluated. DH and SDS-PAGE revealed higher proteolytic activity of pepsin compared to other enzymes. Amino acid analysis showed that the functional amino acids such as antioxidant types were most predominant in H-Pep compared to two other samples. Antioxidant activity of hydrolysates was found to be affected by the type of enzyme and the concentration of hydrolysates. There was a significant difference (p < 0.05) between antioxidant activity of different hydrolysates. The highest antioxidant activity in terms of Trolox equivalent antioxidant capacity (0.23-2.75 mM), DPPH (33.3%-64.8%), and hydroxyl (33.7%-63.2%) radical scavenging activities, chelation of iron (33.2%-62.5%) and copper (30.2%-50.5%) metals, and total antioxidant activity (0.65-0.85) was obtained for H-Pep followed by H-Pan and H-Tri samples. Antibacterial tests showed that pepsin-hydrolyzed protein was not significantly (P > 0.05) effective against E. coli at any concentrations, however, it showed significant (P < 0.05) concentration-dependent effect against S. aureus (with inhibition zones of 15-25 mm). Cytotoxicity results revealed that CPP, as a nonhydrolyzed protein, did not generally show antiproliferative activity, however, a significant (P < 0.05) ability of H-Pep hydrolysate in decreasing HT-29 colon cancer cell line viability was seen in a concentration-dependent manner (the lowest cell viability of 32% at 5 mg/mL). Overall, investigating the application of protein-based hydrolysates is one of the possible strategies that govern their applied intentions as preservatives and nutraceuticals in the food and pharmaceutical industries.

Application of structurally modified WPC in combination with maltodextrin for microencapsulation of Roselle (Hibiscus sabdariffa) extract as a natural colorant source for gummy candy.

The aim of this work was to improve the stability of Roselle extract (RE) by spray-drying using maltodextrin (MD) alone, and in combination with WPC in the forms of unmodified and modified (via ultrasonication, UWPC, or enzymatic hydrolysis, HWPC). Enzymatic hydrolysis by improving the surface activity of WPC increased spray-drying yield (75.1 %), and improved physical (flow) and functional (solubility, and emulsifying) properties of obtained microparticles. Degree of hydrolysis of the primary WPC (2.6 %) was increased to 6.1 % and 24.6 % after ultrasonication and hydrolysis, respectively. Both modifications caused a significant increase in the solubility of WPC, in a way that initial solubility (10.6 %, at pH = 5) was significantly increased to 25.5 % in UWPC, and to 87.3 % in HWPC (P < 0.05). Furthermore, emulsifying activity (20.6 m2/g) and emulsifying stability (17 %) indices of primary WPC (at pH = 5) were significantly increased to 32 m2/g and 30 % in UWPC, and to 92.4 m2/g and 69.0 % in HWPC, respectively (P < 0.05). FT-IR analysis indicated successful encapsulation of RE within carriers' matrix. According to FE-SEM study, the surface morphology of microparticles was improved when modified HWPC was used as a carrier. Microencapsulation of RE with HWPC showed the highest contents of total phenolic compounds (13.3 mg GAE/mL), total anthocyanins (9.1 mg C3G/L) as well as a higher retention of antioxidant activity according to ABTS+ (85.0 %) and DPPH (79.5 %) radicals scavenging assays. Considering all properties of microparticles obtained by HWPC next to their color attributes, it can be concluded that HWPC-RE powders could be used as natural colorant and antioxidant source for the fortification of gummy candy. Gummy candy obtained using 6 % concentration of the above powder gave the highest overall sensory scores.

Electrospun plant protein-based nanofibers loaded with sakacin as a promising bacteriocin source for active packaging against Listeria monocytogenes in quail breast.

The main objective of this study was to fabricate nanofibers from zein incorporated with two concentrations of sakacin (9 and 18 AU/mL) with anti-Listeria properties by electrospinning technique. The efficacies of the resulting active nanofibers against L. innocua, in quail breast during 24 days of refrigerated storage (4 ± 1 °C) were evaluated. The minimum inhibitory concentration (MIC) of bacteriocin against L. innocua was approximate 9 AU/mL. Fourier-transform infrared spectra of bacteriocin-loaded nanofibers indicated characteristic peaks of zein and sakacin and that the nanofibers showed an encapsulation efficiency close to 91.5 %. The thermal stability of sakacin increased by electrospinning. Scanning electron microscopy images showed that nanofibers prepared from electrospinning zein/sakacin solutions exhibited smooth and continuous nanofibers with no defects with an average diameter between 236 and 275 nm. The presence of sakacin led to decreased contact angle properties. Nanofibers with 18 AU/mL sakacin exhibited the highest zone of inhibition of 226.14 ± 8.05 mm. The lowest L. innocua (6.1 logs CFU/cm2) growth after 24 days at 4 °C were obtained in quail breast wrapped with zein containing 18 AU/mL sakacin. The results demonstrate an outlook for the potential use of zein nanofibers containing sakacin to reduce L. innocua contamination in ready-to-eat (RTE) products.

Biological and thermodynamic stabilization of lipid-based delivery systems through natural biopolymers; controlled release and molecular dynamics simulations.

Nowadays, the use of lipid-based nanocarriers for the targeted and controlled delivery of a variety of hydrophobic and hydrophilic bioactive-compounds and drugs has increased significantly. However, challenges such as thermodynamic instability, oxidation, and degradation of lipid membranes, as well as the unintended release of loaded compounds, have limited the use of these systems in the food and pharmaceutical industries. Therefore, the present study reviews the latest achievements in evaluating the characteristics, production methods, challenges, functional, and biological stabilization strategies of lipid-based carriers (including changes in formulation composition, structural modification, membrane-rigidity, and finally monolayer or multilayer coating with biopolymers) in different conditions, as well as molecular dynamics simulations. The scientists' findings indicate the effect of natural biopolymers (such as chitosan, calcium alginate, pectin, dextran, xanthan, caseins, gelatin, whey-proteins, zein, and etc.) in modifying the external structure of lipid-based carriers, improving thermodynamic stability and resistance of membranes to physicochemical and mechanical tensions. However, depending on the type of bioactive compound as well as the design and production goals of the delivery-system, selecting the appropriate biopolymer has a significant impact on the stability of vesicles and maintaining the bioaccessibility of the loaded-compounds due to the stresses caused by the storage-conditions, formulation, processing and gastrointestinal tract.

Microencapsulation of Yerba mate extract: The efficacy of polysaccharide/protein hydrocolloids on physical, microstructural, functional, and antioxidant properties.

Effects of hydrolyzed whey protein concentrate (WPC) and its combination with polysaccharides as wall material in spray-drying microencapsulation of Yerba mate extract (YME) have not been investigated yet. Therefore, it is hypothesized that the surface-active properties of WPC or WPC-hydrolysate may improve different properties of spray-dried microcapsules (such as physicochemical, structural, functional and morphological properties) compared to neat MD and GA. Thus, the objective of current study was to produce microcapsules loaded with YME by different carrier combinations. Effect of maltodextrin (MD), maltodextrin-gum Arabic (MD-GA), maltodextrin-whey protein concentrate (MD-WPC), and maltodextrin-hydrolyzed WPC (MD-HWPC) as encapsulating hydrocolloids was studied on physicochemical, functional, structural, antioxidant and morphological characteristics of the spray-dried YME. The type of carrier significantly affected spray dying yield. Enzymatic hydrolysis by improving the surface activity of WPC increased its efficiency as a carrier and produced particles with high production yield (about 68 %) and excellent physical, functional, hygroscopicity and flowability indices. Chemical structure characterization by FTIR indicated the placement of phenolic compounds of the extract in the carrier matrix. FE-SEM study showed that the microcapsules produced with polysaccharide-based carriers were completely wrinkled, whereas, the surface morphology of particles was improved when protein-based carriers were applied. Among the produced samples, the highest amount of TPC (3.26 mg GAE/mL), inhibition of DPPH (76.4 %), ABTS (88.1 %) and hydroxyl (78.1 %) free radicals were related to microencapsulated extract with MD-HWPC. The results of this research can be used to stabilize plant extracts and produce powders with appropriate physicochemical properties and biological activity.

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.

Modification of Whey Proteins by Sonication and Hydrolysis for the Emulsification and Spray Drying Encapsulation of Grape Seed Oil.

In this study, whey protein concentrate (WPC) was sonicated or partially hydrolyzed by Alcalase, then examined as an emulsifier and carrier for the emulsification and spray drying of grape seed oil (GSO)-in-water emulsions. The modification treatments increased the free amino acid content and antioxidant activity (against DPPH and ABTS free radicals), as well as, the solubility, emulsifying, and foaming activities of WPC. The modified WPC-stabilized emulsions had smaller, more homogeneous droplets and a higher zeta potential as compared to intact WPC. The corresponding spray-dried powders also showed improved encapsulation efficiency, oxidative stability, reconstitution ability, flowability, solubility, and hygroscopicity. The morphology of particles obtained from the primary WPC (matrix type, irregular with surface pores) and modified WPC (reservoir type, wrinkled with surface indentations), as well as the oxidative stability of the GSO were influenced by the functional characteristics and antioxidant activity of the carriers. Changes in the secondary structures and amide regions of WPC, as well as the embedding of GSO in its matrix, were deduced from FTIR spectra after modifications. Partial enzymolysis had better results than ultrasonication; hence, the WPC hydrolysates are recommended as emulsifiers, carriers, and antioxidants for the delivery and protection of bioactive compounds.

Advances in plant gum polysaccharides; Sources, techno-functional properties, and applications in the food industry - A review.

Gums are biopolymers with many functional and innovative properties in the food industry. They are complex carbohydrate biomolecules capable of bonding with water, generating gel and mucilage structures. Among different gums, plant-based gums (PBGs) are one of the most important groups as they possess key characteristics such as stabilizing potential, viscosity enhancement, emulsifying and surface-active property, extensive adaptability, and affordability leading to their application in the formulation of food products. PBGs are extensively used in the confectionery, encapsulation of flavors and colors, emulsions, carrier agents, as dietary fiber, thickening/foaming agent, formulation of functional foods, and stabilizers in beverages and other food products. More importantly, researchers and food industries have been engrossed to reveal the undisclosed potential of PBGs and the impact of chemical composition and molecular structure on their techno-functional characteristics Therefore, this review study aims to explore the structure and physiochemical/functional properties of PBGs and their application as techno-functional materials in different food industries.

Spray drying encapsulation of bioactive compounds within protein-based carriers; different options and applications.

Spray-drying is known as a common and economical technique for the encapsulation of various nutrients and bioactive compounds. However, shear and thermal tensions during atomization and dehydration, as well as physicochemical instability during storage, result in a loss of these compounds. As a solution, bioactives are stabilized into different carriers, among which proteins and peptides are of particular importance due to their functional properties, surface activity, and film/shell formability around particles. Given the importance of stabilization of bioactive compounds during spray drying, this paper focuses on the role of composition and type of carriers, as well as the characteristics and efficiency of various protein-based carriers in the encapsulation and maintaining of physicochemical, structural, and functional properties, along with biological activity of bioactive compounds (e.g., oleoresins, sterols, polyphenols, anthocyanins, carotenoids, probiotics, and peptides), and nutrients (e.g., vitamins, fatty acids and minerals) alone or in combination with other biopolymers.

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.

Effect of chitosan coating on the properties of nanoliposomes loaded with flaxseed-peptide fractions: Stability during spray-drying.

In this study, production of peptide fractions with different molecular weights (10, 30, and 100 KDa) from flaxseed hydrolysates was investigated. The peptide-fraction with lowest MW (10 KDa) showed the highest antioxidant activity (AA); therefore, selected and loaded into nanoliposomes. Then, the effect of chitosan coating (0.1-0.8% w/v) on the physicochemical features, stability, and release rate of loaded nanoliposomes was assessed. Nanoliposomes coated with 0.4% chitosan exhibited a higher physical stability and encapsulation efficiency (EE) compared with other samples. Then, stabilization of uncoated/coated nanoliposomes by spray-drying within the maltodextrin matrix was investigated. FTIR results indicated incorporation of peptides into the polar and non-polar regions of vesicles and formation of the hydrogen bonds with phosphatidylcholine. Chitosan coating significantly enhanced the physical stability, EE, and AA retention of nanoliposomes after powder reconstitution process by increasing the bilayer membrane rigidity against the dehydration tension and decreasing the leakage of loaded peptides.