Electrospraying assisted by pressurized gas as an innovative high-throughput process for the microencapsulation and stabilization of docosahexaenoic acid-enriched fish oil in zein prolamine

Revolutionizing Cardiovascular Health with Nano Encapsulated Omega-3 Fatty Acids: A Nano-Solution Approach

Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) offer diverse health benefits, such as supporting cardiovascular health, improving cognitive function, promoting joint and musculoskeletal health, and contributing to healthy aging. Despite their advantages, challenges like oxidation susceptibility, low bioavailability, and potential adverse effects at high doses persist. Nanoparticle encapsulation emerges as a promising avenue to address these limitations while preserving stability, enhanced bioavailability, and controlled release. This comprehensive review explores the therapeutic roles of omega-3 fatty acids, critically appraising their shortcomings and delving into modern encapsulation strategies. Furthermore, it explores the potential advantages of metal-organic framework nanoparticles (MOF NPs) compared to other commonly utilized nanoparticles in improving the therapeutic effectiveness of omega-3 fatty acids within drug delivery systems (DDSs). Additionally, it outlines future research directions to fully exploit the therapeutic benefits of these encapsulated omega-3 formulations for cardiovascular disease treatment.

Non-emulsion-based encapsulation of fish oil by coaxial electrospraying assisted by pressurized gas enhances the oxidative stability of a capsule-fortified salad dressing

The influence of the encapsulation technology (spray-drying, mono- or coaxial electrospraying assisted by pressurized gas, EAPG) and the oil load (13, 26 or 39 wt%) on the oxidative stability of: i) fish oil-loaded capsules, and ii) capsule-fortified salad dressings were investigated. The highest encapsulation efficiency (EE > 83%) was achieved by the emulsion-based encapsulation methods (e.g., spray-drying and monoaxial EAPG), irrespective of the oil load. Nonetheless, monoaxially EAPG capsules were the most oxidized during storage due to their increased surface-to-volume ratio. On the contrary, non-emulsion-based coaxial EAPG resulted in low lipid oxidation after processing and subsequent storage. The oxidative stability of the capsule-fortified salad dressings correlated well with that of the encapsulates, with the dressing fortified with the coaxially EAPG capsules showing significantly lower levels of oxidation. Our results show that the fortification approach (e.g., emulsion or non-emulsion-based delivery systems) significantly influenced the oxidative stability of the enriched food matrix.

Strategies for improving loading of emulsion-based functional oil powder

Functional oil is type of oil that is beneficial to human health and has nutritional value, however, functional oils are rich in bioactive substances such as polyunsaturated fatty acids which are sensitive to environmental factors and are susceptible to oxidation or decomposition. Construction of emulsion-based oil powder is a promising approach for improving the stability and solubility of functional oils. However, the low effective loading of oil in powder is the main challenge limiting encapsulation technology. This manuscript focuses on reviewing the current research progress of emulsion-based functional oil powder construction and systematically summarizes the processing characteristics of emulsion-based oil powder with high payload and summarizing the strategies to enhance the payload of powder in term of emulsification and drying, respectively. The impact of emulsion formation on oil powder production is discussed from different characteristics of emulsions, including emulsion composition, emulsification methods and emulsion types. In addition, the current status of improving material loading performance by various modifications to the drying technology is discussed, including the addition of drying processing additives, changes in drying parameters and the effect of innovative technological means.

Dragon's Blood Sap Microencapsulation within Whey Protein Concentrate and Zein Using Electrospraying Assisted by Pressurized Gas Technology

Dragon's blood sap (DBS) obtained from the bark of Croton lechleri (Müll, Arg.) is a complex herbal remedy of pharmacological interest due to its high content in polyphenols, specifically proanthocyanidins. In this paper, electrospraying assisted by pressurized gas (EAPG) was first compared with freeze-drying to dry natural DBS. Secondly, EAPG was used for the first time to entrap natural DBS at room temperature into two different encapsulation matrices, i.e., whey protein concentrate (WPC) and zein (ZN), using different ratios of encapsulant material: bioactive compound, for instance 2:1 w/w and 1:1 w/w. The obtained particles were characterized in terms of morphology, total soluble polyphenolic content (TSP), antioxidant activity, and photo-oxidation stability during the 40 days of the experiment. Regarding the drying process, EAPG produced spherical particles with sizes of 11.38 ± 4.34 µm, whereas freeze-drying produced irregular particles with a broad particle size distribution. However, no significant differences were detected between DBS dried by EAPG or freeze-drying in TSP, antioxidant activity, and photo-oxidation stability, confirming that EAPG is a mild drying process suitable to dry sensitive bioactive compounds. Regarding the encapsulation process, the DBS encapsulated within the WPC produced smooth spherical microparticles, with average sizes of 11.28 ± 4.28 µm and 12.77 ± 4.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The DBS was also encapsulated into ZN producing rough spherical microparticles, with average sizes of 6.37 ± 1.67 µm and 7.58 ± 2.54 µm for ratios 1:1 w/w and 2:1 w/w, respectively. The TSP was not affected during the encapsulation process. However, a slight reduction in antioxidant activity measured by DPPH was observed during encapsulation. An accelerated photo-oxidation test under ultraviolet light confirmed that the encapsulated DBS showed an increased oxidative stability in comparison with the non-encapsulated DBS, with the stability being enhanced for the ratio of 2:1 w/w. Among the encapsulating materials and according to the ATR-FTIR results, ZN showed increased protection against UV light. The obtained results demonstrate the potential of EAPG technology in the drying or encapsulation of sensitive natural bioactive compounds in a continuous process available at an industrial scale, which could be an alternative to freeze-drying.

Encapsulation of Bioactive Peptides by Spray-Drying and Electrospraying

Bioactive peptides derived from enzymatic hydrolysis are gaining attention for the production of supplements, pharmaceutical compounds, and functional foods. However, their inclusion in oral delivery systems is constrained by their high susceptibility to degradation during human gastrointestinal digestion. Encapsulating techniques can be used to stabilize functional ingredients, helping to maintain their activity after processing, storage, and digestion, thus improving their bioaccessibility. Monoaxial spray-drying and electrospraying are common and economical techniques used for the encapsulation of nutrients and bioactive compounds in both the pharmaceutical and food industries. Although less studied, the coaxial configuration of both techniques could potentially improve the stabilization of protein-based bioactives via the formation of shell-core structures. This article reviews the application of these techniques, both monoaxial and coaxial configurations, for the encapsulation of bioactive peptides and protein hydrolysates, focusing on the factors affecting the properties of the encapsulates, such as the formulation of the feed solution, selection of carrier and solvent, as well as the processing conditions used. Furthermore, this review covers the release, retention of bioactivity, and stability of peptide-loaded encapsulates after processing and digestion.

Highly Valuable Fish Oil: Formation Process, Enrichment, Subsequent Utilization, and Storage of Eicosapentaenoic Acid Ethyl Esters

In recent years, as the demand for precision nutrition is continuously increasing, scientific studies have shown that high-purity eicosapentaenoic acid ethyl ester (EPA-EE) functions more efficiently than mixed omega-3 polyunsaturated fatty acid preparations in diseases such as hyperlipidemia, heart disease, major depression, and heart disease; therefore, the market demand for EPA-EE is growing by the day. In this paper, we attempt to review EPA-EE from a whole-manufacturing-chain perspective. First, the extraction, refining, and ethanolysis processes (fish oil and ethanol undergo transesterification) of EPA-EE are described, emphasizing the potential of green substitute technologies. Then, the method of EPA enrichment is thoroughly detailed, the pros and cons of different methods are compared, and current developments in monomer production techniques are addressed. Finally, a summary of current advanced strategies for dealing with the low oxidative stability and low bioavailability of EPA-EE is presented. In conclusion, understanding the entire production process of EPA-EE will enable us to govern each step from a macro perspective and accomplish the best use of EPA-EE in a more cost-effective and environmentally friendly way.

Micro-Encapsulated Microalgae Oil Supplementation Has No Systematic Effect on the Odor of Vanilla Shake-Test of an Electronic Nose

In this study, we aimed to carry out the efficient fortification of vanilla milkshakes with micro-encapsulated microalgae oil (brand: S17-P100) without distorting the product’s odor. A 10-step oil-enrichment protocol was developed using an inclusion rate of 0.2 to 2 w/w%. Fatty acid (FA) profile analysis was performed using methyl esters with the GC-MS technique, and the recovery of docosahexaenoic acid (C22:6 n3, DHA) was robust (r = 0.97, p < 0.001). The enrichment process increased the DHA level to 412 mg/100 g. Based on this finding, a flash-GC-based electronic nose (e-nose) was used to describe the product’s odor. Applying principal component (PC) analysis to the acquired sensor data revealed that for the first four PCs, only PC3 (6.5%) showed a difference between the control and the supplemented products. However, no systematic pattern of odor profiles corresponding to the percentages of supplementation was observed within the PC planes. Similarly, when discriminant factor analysis (DFA) was applied, though a classification of the control and supplemented products, we obtained a validation score of 98%, and the classification pattern of the odor profiles did not follow a systematic format. Again, when a more targeted approach such as the partial least square regression (PLSR) was used on the most dominant sensors, a weak relationship (R2 = 0.50) was observed, indicating that there was no linear combination of the qualitative sensors’ signals that could accurately describe the supplemented concentration variation. It can therefore be inferred that no detectable off-odor was present as a side effect of the increase in the oil concentration. Some volatile compounds of importance in regard to the odor, such as ethylacetate, ethyl-isobutarate, pentanal and pentyl butanoate, were found in the supplemented product. Although the presence of yeasts and molds was excluded from the product, ethanol was detected in all samples, but with an intensity that was insufficient to cause an off-odor.

Recent Developments in the Microencapsulation of Fish Oil and Natural Extracts: Procedure, Quality Evaluation and Food Enrichment

Due to the beneficial health effects of omega-3 fatty acids and antioxidants and their limited stability in response to environmental and processing factors, there is an increasing interest in microencapsulating them to improve their stability. However, despite recent developments in the field, no specific review focusing on these topics has been published in the last few years. This work aimed to review the most recent developments in the microencapsulation of fish oil and natural antioxidant compounds. The impact of the wall material and the procedures on the quality of the microencapsulates were preferably evaluated, while their addition to foods has only been studied in a few works. The homogenization technique, the wall-material ratio and the microencapsulation technique were also extensively studied. Microcapsules were mainly analyzed for size, microencapsulation efficiency, morphology and moisture, while in vitro digestion, flowing properties, yield percentage and Fourier transform infrared spectroscopy (FTIR) were used more sparingly. Findings highlighted the importance of optimizing the most influential variables of the microencapsulation procedure. Further studies should focus on extending the range of analytical techniques upon which the optimization of microcapsules is based and on addressing the consequences of the addition of microcapsules to food products.

A Narrative Review on Various Oil Extraction Methods, Encapsulation Processes, Fatty Acid Profiles, Oxidative Stability, and Medicinal Properties of Black Seed (Nigella sativa)

The current review investigates the effects of black seed (Nigella sativa) on human health, which is also used to encapsulate and oxidative stable in different food products. In recent decades, many extraction methods, such as cold pressing, supercritical fluid extraction, Soxhlet extraction, hydro distillation (HD) method, microwave-assisted extraction (MAE), ultrasound-assisted extraction, steam distillation, and accelerated solvent extraction (ASE) have been used to extract the oils from black seeds under optimal conditions. Black seed oil contains essential fatty acids, in which the major fatty acids are linoleic, oleic, and palmitic acids. The oxidative stability of black seed oil is very low, due to various environmental conditions or factors (temperature and light) affecting the stability. The oxidative stability of black seed oil has been increased by using encapsulation methods, including nanoprecipitation, ultra-sonication, spray-drying, nanoprecipitation, electrohydrodynamic, atomization, freeze-drying, a electrospray technique, and coaxial electrospraying. Black seed, oil, microcapsules, and their components have been used in various food processing, pharmaceutical, nutraceutical, and cosmetics industries as functional ingredients for multiple purposes. Black seed and oil contain thymoquinone as a major component, which has anti-oxidant, -diabetic, -inflammatory, -cancer, -viral, and -microbial properties, due to its phenolic compounds. Many clinical and experimental studies have indicated that the black seed and their by-products can be used to reduce the risk of cardiovascular diseases, chronic cancer, diabetes, oxidative stress, polycystic ovary syndrome, metabolic disorders, hypertension, asthma, and skin disorders. In this review, we are focusing on black seed oil composition and increasing the stability using different encapsulation methods. It is used in various food products to increase the human nutrition and health properties.

Effect of Whey Protein Purity on the Characteristics of Algae Oil-Loaded Encapsulates Obtained by Electrospraying Assisted by Pressurized Gas

In this paper, the effect of protein purity in three different whey protein grades on the characteristics of algae oil encapsulates obtained via room-temperature electrospraying assisted by pressurized gas (EAPG) encapsulation process was studied. Three different commercial grades of whey protein purity were evaluated, namely 35, 80, and 90 wt.%. Oil nanodroplets with an average size of 600 nm were homogeneously entrapped into whey protein microparticles 3 µm in size. However, the sphericity and the surface smoothness of the microparticles increased by increasing the protein purity in the grades of whey protein studied. The porosity of the microparticles was also dependent on protein purity as determined by nitrogen adsorption-desorption isotherms, being smaller for larger contents of protein. Interestingly, the lowest extractable oil was obtained with WP35, probably due to the high content of lactose. The peroxide values confirmed the superior protective effect of the protein, obtaining the smallest peroxide value for WP90, a result that is consistent with its reduced porosity and with its lower permeability to oxygen, as confirmed by the fluorescence decay-oxygen consumption method. The accelerated stability assay against oxidation confirmed the higher protection of the WP80 and WP90. In addition, the increased content in protein implied a higher thermal stability according to the thermogravimetric analysis. These results further confirm the importance of the adequate selection of the composition of wall materials together with the encapsulation method.

Future of Structured Lipids: Enzymatic Synthesis and Their New Applications in Food Systems

Structured lipids (SLs) refer to a new type of functional lipid obtained by modifying natural triacylglycerol (TAG) through the restructuring of fatty acids, thereby altering the composition, structure, and distribution of fatty acids attached to the glycerol backbones. Due to the unique functional characteristics of SLs (easy to absorb, low in calories, reduced serum TAG, etc.), there is increasing interest in the research and application of SLs. SLs were initially prepared using chemical methods. With the wide application of enzymes in industries and the advantages of enzymatic synthesis (mild reaction conditions, high catalytic efficiency, environmental friendliness, etc.), synthesis of SLs using lipase has aroused great interest. This review summarizes the reaction system of SL production and introduces the enzymatic synthesis and application of some of the latest SLs discussed/developed in recent years, including medium- to long-chain triacylglycerol (MLCT), diacylglycerol (DAG), EPA- and DHA-enriched TAG, human milk fat substitutes, and esterified propoxylated glycerol (EPG). Lastly, several new ways of applying SLs (powdered oil, DAG plastic fat, inert gas spray oil, and emulsion) in the future food industry are also highlighted.

Food-grade systems for delivery of DHA and EPA: Opportunities, fabrication, characterization and future perspectives

Docosahexaenoic acid (C22: 6n-3, DHA) and eicosapentaenoic acid (C20: 5n-3, EPA) have been shown to provide the opportunity to inhibit onset and escalation of chronic diseases. Nevertheless, their undesirable characteristics including poor water solubility, oxidation sensitivity, high melting point and unpleasant sensory attributes hinder their application in the food industry. In recent years, utilizing food-grade delivery systems to deliver DHA/EPA and improve their biological efficacy has emerged as an attractive approach with fascinating prospects. This review focuses on introducing potential delivery systems for DHA/EPA, including microemulsions, nanoemulsions, Pickering emulsions, hydrogels, lipid particles, oleogels, liposomes, microcapsules and micelles. The opportunities, fabrication and characterization of these delivery systems loaded with DHA/EPA are highlighted. Besides, food sources of DHA/EPA, their benefits to the human body and a series of challenges for effective utilization of DHA/EPA are discussed. Promising future research trends of food-grade systems for delivery of DHA/EPA are also presented. Conducting in vivo experiments, applying DHA/EPA-loaded delivery systems into real food, improving the applicability of such delivery systems in industrial production, co-encapsulating DHA/EPA with other substances, seeking measures to improve the performance of existing delivery systems and developing novel food-grade delivery systems inspired by other fields are various future considerations.

Electrohydrodynamic processing of natural polymers for active food packaging: A comprehensive review

The active packaging materials fabricated using natural polymers is increasing in recent years. Electrohydrodynamic processing has drawn attention in active food packaging due to its potential in fabricating materials with advanced structural and functional properties. These materials have the significant capability in enhancing food's quality, safety, and shelf-life. Through electrospinning and electrospray, fibers and particles are encapsulated with bioactive compounds for active packaging applications. Understanding the principle behind electrohydrodynamics provides fundamentals in modulating the material's physicochemical properties based on the operating parameters. This review provides a deep understanding of electrospray and electrospinning, along with their advantages and recent innovations, from food packaging perspectives. The natural polymers suitable for developing active packaging films and coatings through electrohydrodynamics are intensely focused. The critical properties of the packaging system are discussed with characterization techniques. Furthermore, the limitations and prospects for natural polymers and electrohydrodynamic processing in active packaging are summarized.

Encapsulation and Protection of Omega-3-Rich Fish Oils Using Food-Grade Delivery Systems

Regular consumption of adequate quantities of lipids rich in omega-3 fatty acids is claimed to provide a broad spectrum of health benefits, such as inhibiting inflammation, cardiovascular diseases, diabetes, arthritis, and ulcerative colitis. Lipids isolated from many marine sources are a rich source of long-chain polyunsaturated fatty acids (PUFAs) in the omega-3 form which are claimed to have particularly high biological activities. Functional food products designed to enhance human health and wellbeing are increasingly being fortified with these omega-3 PUFAs because of their potential nutritional and health benefits. However, food fortification with PUFAs is challenging because of their low water-solubility, their tendency to rapidly oxidize, and their variable bioavailability. These challenges can be addressed using advanced encapsulation technologies, which typically involve incorporating the omega-3 oils into well-designed colloidal particles fabricated from food-grade ingredients, such as liposomes, emulsion droplets, nanostructured lipid carriers, or microgels. These omega-3-enriched colloidal dispersions can be used in a fluid form or they can be converted into a powdered form using spray-drying, which facilitates their handling and storage, as well as prolonging their shelf life. In this review, we provide an overview of marine-based omega-3 fatty acid sources, discuss their health benefits, highlight the challenges involved with their utilization in functional foods, and present the different encapsulation technologies that can be used to improve their performance.

Nanostructured Valsartan Microparticles with Enhanced Bioavailability Produced by High-Throughput Electrohydrodynamic Room-Temperature Atomization

The high-throughput drying and encapsulation technique called electrospraying assisted by pressurized gas (EAPG) was used for the first time to produce nanostructured valsartan within microparticles of excipients. Valsartan, a poorly absorbed and lipid-soluble drug, was selected since it is considered a good model for BCS class II drugs. Two different polymeric matrices were selected as excipients, i.e., hydroxypropyl methylcellulose (HPMC) and lactose monohydrate, while Span 20 was used as a surfactant. The produced 80% valsartan loading formulations were characterized in terms of morphology, crystallinity, in vitro release, in vitro Caco-2 cells’ permeability, and in vivo pharmacokinetic study. Spherical microparticles of ca. 4 μm were obtained within which valsartan nanoparticles were seen to range from 150 to 650 nm. Wide-angle X-ray scattering and differential scanning calorimetry confirmed that valsartan had a lower and/or more ill-defined crystallinity than the commercial source, and photon correlation spectroscopy and transmission electron microscopy proved that it was dispersed and distributed in the form of nanoparticles of controlled size. In vitro dissolution tests showed that the HPMC formulation with the lowest API particle size, i.e., 150 nm, dissolved 2.5-fold faster than the commercial valsartan in the first 10 min. This formulation also showed a 4-fold faster in vitro permeability than the commercial valsartan and a 3-fold higher systemic exposure than the commercial sample. The results proved the potential of the EAPG processing technique for the production of safe-to-handle microparticles containing high quantities of a highly dispersed and distributed nanonized BCS class II model drug with enhanced bioavailability.

Mechanistic understanding and potential application of electrospraying in food processing: a review

Electrospraying (ESPR) is a cost effective, flexible, and facile method that has been used in the pharmaceutical industry, and thanks to its wide variety of uses such as bioactive compound encapsulation, micronization, and food product coating, which have received a great attention in the food market. It uses a jet of polymer solution for processing food and food-derived products. Droplet size can be extremely small up to nanometers and can be regulated by altering applied voltage and flow rate. Compared to conventional techniques, it is simple, cost effective, uses less solvent and products are obtained in one step with a very high encapsulation efficiency (EE). Encapsulation provided using it protects bioactives from moisture, thermal, oxidative, and mechanical stresses, and thus provides them a good storage stability which will help in increasing the application of these ingredients in food formulation. This technique has an enormous potential for increasing the shelf life of fruit and vegetables through coating and improvement of eating quality. This study is aimed at overviewing the operating principles of ESPR, working parameters, applications, and advantages in the food sector. The article also covers new ESPR techniques like supercritical assisted ESPR and ESPR assisted by pressurized gas (EAPG) which have high yield as compared to conventional ESPR. This article is enriched with good information for research and development in ESPR techniques for development of novel foods.

Room Temperature Nanoencapsulation of Bioactive Eicosapentaenoic Acid Rich Oil within Whey Protein Microparticles

In this study, emulsion electrospraying assisted by pressurized gas (EAPG) has been performed for the first time to entrap ca. 760 nm droplets of the bioactive eicosapentaenoic acid (EPA)-rich oil into whey protein concentrate (WPC) at room temperature. The submicron droplets of EPA oil were encapsulated within WPC spherical microparticles, with sizes around 5 µm. The EPA oil did not oxidize in the course of the encapsulation performed at 25 °C and in the presence of air, as corroborated by the peroxide value measurements. Attenuated Total Reflection-Fourier Transform Infrared spectroscopy and oxygen consumption tests confirmed that the encapsulated EPA-rich oil showed increased oxidative stability in comparison with the free oil during an accelerated oxidation test under ultraviolet light. Moreover, the encapsulated EPA-rich oil showed increased thermal stability in comparison with the free oil, as measured by oxidative thermogravimetric analysis. The encapsulated EPA-rich oil showed a somewhat reduced organoleptic impact in contrast with the neat EPA oil using rehydrated powdered milk as a reference. Finally, the oxidative stability by thermogravimetric analysis and organoleptic impact of mixtures of EPA and docosahexaenoic acid (DHA)-loaded microparticles was also studied, suggesting an overall reduced organoleptic impact compared to pure EPA. The results here suggest that it is possible to encapsulate 80% polyunsaturated fatty acids (PUFAs)-enriched oils by emulsion EAPG technology at room temperature, which could be used to produce personalized nutraceuticals or pharmaceuticals alone or in combination with other microparticles encapsulating different PUFAs to obtain different targeted health and organoleptic benefits.

A systematic review and meta-analysis of fish oil encapsulation within different micro/nanocarriers

Fish oil is one of the most important sources of omega 3 polyunsaturated fatty acids (PUFAs), especially eicosapentaenoic acid and docosahexaenoic acid which are the most important PUFAs with several health benefits. However, PUFAs are prone to oxidation and have a poor water solubility which limits the use of fish oils into food formulations. Encapsulation techniques can be applied to overcome these challenges. There is a large number of published micro/nanoencapsulation papers, where each of them contains a limited number of wall materials, feed formulation, encapsulation technique, and storage conditions. Therefore, without systematic evaluation of the data extracted from available studies, the design of functional foods containing fish oil would not be very successful. The objective of this systematic review is a meta-analysis of published researches on the nano/microencapsulation of fish oil. A comprehensive literature search was performed between 1 October and 31 December 2019 with encapsulation, fish oil, and oxidative stability keywords. Overall, 39 qualified articles were selected for the statistical analysis. Based on the technique used for encapsulation, the fish oil-loaded carriers were classified into four main groups: (a) spray-dried particles; (b) freeze-dried particles; (c) electrospun fibers and electrosprayed capsules; and (d) other carriers prepared by supercritical antisolvent, gelation, liposomes, spray-freeze drying, and transglutaminase catalyzed cross-linking. The three most frequent methods applied for fish oil encapsulation were spray drying (42.86%), freeze drying (21.43%), and electrohydrodynamic (19.04%) methods, respectively. Averagely, the best encapsulation efficiency was obtained for electrohydrodynamic processes. Also, the combination of polysaccharide-protein based wall materials provided the best performance in terms of fish oil encapsulation efficiency.

Protein encapsulation by electrospinning and electrospraying

Given the increasing interest in the use of peptide- and protein-based agents in therapeutic strategies, it is fundamental to develop delivery systems capable of preserving the biological activity of these molecules upon administration, and which can provide tuneable release profiles. Electrohydrodynamic (EHD) techniques, encompassing electrospinning and electrospraying, allow the generation of fibres and particles with high surface area-to-volume ratios, versatile architectures, and highly controllable release profiles. This review is focused on exploring the potential of different EHD methods (including blend, emulsion, and co-/multi-axial electrospinning and electrospraying) for the development of peptide and protein delivery systems. An overview of the principles of each technique is first presented, followed by a survey of the literature on the encapsulation of enzymes, growth factors, antibodies, hormones, and vaccine antigens using EHD approaches. The possibility for localised delivery using stimuli-responsive systems is also explored. Finally, the advantages and challenges with each EHD method are summarised, and the necessary steps for clinical translation and scaled-up production of electrospun and electrosprayed protein delivery systems are discussed.

Effect of adjusting pH and chondroitin sulfate on the formation of curcumin-zein nanoparticles: Synthesis, characterization and morphology

This study is aiming to investigate the stabilizing effect of chondroitin sulfate (CS) on the preparation of curcumin nanoparticles (NPs). The results showed that adding CS before the anti-solvent process of zein (Z) at pH7 could fabricate most stable NPs (Cur/CS/Z-pH7) with particle size of 197 ± 5 nm and zeta-potential of -48.4 ± 1.9 mV. The pH had a significant effect on the fabrication of NPs. Cur/CS/Z-pH7 was more stable than Cur/CS/Z-pH3, while Cur/Z-CS-pH3 was more stable than the Cur/Z-CS-pH7. According to the results of XRD, FTIR, DSC and CD, CS can form irreversible macromolecular complexes with zein through non-electrostatic interactions during the anti-solvent process (Cur/CS/Z-pH7, Cur/CS/Z-pH3). However, CS was adsorbed on the surface of Zein NPs by electrostatic interaction (Cur/Z-CS-pH7, Cur/Z-CS-pH3), when CS was added after anti-solvent process of zein. These results illustrated that it is better to add CS before the anti-solvent process of zein at neutral pH.

Nanodroplets of Docosahexaenoic Acid-Enriched Algae Oil Encapsulated within Microparticles of Hydrocolloids by Emulsion Electrospraying Assisted by Pressurized Gas

Long chain polyunsaturated omega-3 fatty acids (PUFAs), namely eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are important functional ingredients due to their well-documented health benefits, but highly susceptible to oxidation. One of the most promising approaches to preserve bioactives is their encapsulation within protective matrices. In this paper, an innovative high throughput encapsulation technique termed as emulsion electrospraying assisted by pressurized gas (EAPG) was used to encapsulate at room temperature nanodroplets of algae oil into two food hydrocolloids, whey protein concentrate and maltodextrin. Spherical encapsulating particles with sizes around 5 µm were obtained, where the oil was homogeneously distributed in nanometric cavities with sizes below 300 nm. Peroxide values under 5 meq/kg, demonstrated that the oil did not suffer from oxidation during the encapsulation process carried out at room temperature. An accelerated stability assay against oxidation under strong UV light was performed to check the protective capacity of the different encapsulating materials. While particles made from whey protein concentrate showed good oxidative stability, particles made from maltodextrin were more susceptible to secondary oxidation, as determined by a methodology put forward in this study based on ATR-FTIR spectroscopy. Further organoleptic testing performed with the encapsulates in a model food product, i.e., milk powder, suggested that the lowest organoleptic impact was seen for the encapsulates made from whey protein concentrate. The obtained results demonstrate the potential of the EAPG technology using whey protein concentrate as the encapsulating matrix, for the stabilization of sensitive bioactive compounds.

Bioactive Multilayer Polylactide Films with Controlled Release Capacity of Gallic Acid Accomplished by Incorporating Electrospun Nanostructured Coatings and Interlayers

The present research reports on the development of bi- and multilayer polylactide (PLA) films by the incorporation of electrospun nanostructured PLA coatings and interlayers containing the antioxidant gallic acid (GA) at 40 wt% onto cast-extruded PLA films. To achieve the bilayer structures, submicron GA-loaded PLA fibers were applied on 200-µm cast PLA films in the form of coatings by electrospinning for 1, 2, and 3 h. For the multilayers, the cast PLA films were first coated on one side by electrospinning, then sandwiched with 10-µm PLA film on the other side, and the resultant whole structure was finally thermally post-treated at 150 °C without pressure. Whereas the bilayer PLA films easily delaminated and lacked transparency, the multilayers showed sufficient adhesion between layers and high transparency for deposition times during electrospinning of up to 2 h. The incorporation of GA positively contributed to delaying the thermal degradation of PLA for approximately 10 °C, as all films were thermally stable up to 345 °C. The in vitro release studies performed in saline medium indicated that the GA released from the bilayer PLA films rapidly increased during the first 5 h of immersion while it stabilized after 45–250 h. Interestingly, the PLA multilayers offered a high sustained release of GA, having the capacity to deliver the bioactive for over 1000 h. In addition, in the whole tested period, the GA released from the PLA films retained most of its antioxidant functionality. Thus, during the first days, the bilayer PLA films can perform as potent vehicles to deliver GA while the multilayer PLA films are able to show a sustained release of the natural antioxidant for extended periods.