Encapsulation of functional lipophilic components in surfactant-based colloidal delivery systems: Vitamin E, vitamin D, and lemon oil

Emulsification and stabilisation technologies used for the inclusion of lipophilic functional ingredients in food systems

Food industry is increasingly using functional ingredients to improve the food product quality. Lipid-containing functional ingredients are important sources of nutrients. This review examines the current state of emulsification and stabilisation technologies for incorporating lipophilic functional ingredients into food systems. Lipophilic functional ingredients, such as omega-3 fatty acids, carotenoids, and fat-soluble vitamins, offer numerous health benefits but present challenges due to their limited solubility in water-based food matrices. Emulsification techniques enable the dispersion of these ingredients in aqueous environments, facilitating their inclusion in a variety of food products. This review highlights recent advances in food emulsion formulation, emulsification methods and stabilisation techniques which, together, improve the stability and bioavailability of lipophilic compounds. The role of various emulsifiers, stabilizers, and encapsulation materials in enhancing the functionality of these ingredients is also explored. Furthermore, the review discusses different stabilisation techniques which can yield in emulsion in a solid or liquid state. By providing a comprehensive overview of current technologies, this review aims to guide future research and application in the development of functional foods enriched with lipophilic ingredients.

Over 100 years of vitamin E: An overview from synthesis and formulation to application in animal nutrition

The groundbreaking discovery of vitamin E by Evans and Bishop in 1922 was an important milestone in vitamin research, inspiring further investigation into its crucial role in both human and animal nutrition. Supplementing vitamin E has been proved to enhance multiple key physiological systems such as the reproductive, circulatory, nervous and muscular systems. As the main antioxidant in the blood and on a cellular level, vitamin E maintains the integrity of both cellular and vascular membranes and thus modulates the immune system. This overview showcases important and innovative routes for synthesizing vitamin E on a commercial scale, provides cutting-edge insights into formulation concepts for successful product form development and emphasizes the importance and future of vitamin E in healthy and sustainable animal nutrition.

"Characterization and stability of α-tocopherol loaded solid lipid nanoparticles formulated with different fully hydrogenated vegetable oils"

Solid lipid nanoparticles can be compatible with several bioactive compounds and confer a differentiated crystalline structure. This study aimed to produce α-tocopherol loaded solid lipid nanoparticles with fully hydrogenated oils and fats from palm oil, soybean oil, and crambe oil, by high-pressure homogenization, using lecithin as an emulsifier. After recrystallization of solid lipid nanoparticles, dispersions were evaluated until 60 days of storage for particle size, polydispersity index, zeta potential, microstructure, dispersion stability and α-tocopherol quantification. α-tocopherol loaded solid lipid nanoparticles showed particle sizes and zeta potential values considered adequate for this type of particle. Presence of α-tocopherol altered thermal behavior of the particles, leading to increased crystallinity, with no changes in polymorphism, when compared to the unloaded solid lipid nanoparticles. All α-tocopherol loaded solid lipid nanoparticles dispersions showed stability with no losses of α-tocopherol, indicating their potential as a carrier for this compound in fortified foods.

Development, characterization, and evaluation of the antioxidant activity of nanocarriers based on surfactant swollen micelles that encapsulate essential oils

This work aimed to compare the performance of two relatively underexplored methods for the swollen micelles (SMs) production as nanocarriers for essential oils (EOs). Origanum vulgare and Thymus vulgaris EOs were examined. The first method (SMs-1), involved a self-assembly process, while the second one (SMs-2), employed titration operation of an emulsion into a surfactant solution for SMs formation. Tween 80 and ethanol were used as surfactant and co-surfactant, respectively. The solubilization kinetics and the saturation concentration of EOs were determined. Particle size (measured by DLS) and encapsulation efficiency (EE) were the control parameters assessed, along with the EOs-loaded SMs' stability during 30 days of storage. Additionally, the EOs-loaded SMs' morphology was analyzed using atomic force microscopy (AFM). Finally, the antioxidant activity through the ABTS+ radical scavenging and the reducing power of EOs encapsulated in SMs was determined. The results showed that the solubilization of EOs in SMs was a rapid process with high EE. EOs-loaded SMs-2 systems exhibited greater colloidal stability and higher EE compared to EOs-loaded SMs-1 systems, showing smaller and more homogeneous particle sizes. Moreover, EOs-loaded SMs-2 systems maintained constant EE throughout the storage period. AFM imaging confirmed the rounded and heterogeneous morphology of EOs-loaded SMs-1 and the smaller, more homogeneous, and spherical morphology of EOs-loaded SMs-2. EOs-loaded SMs-2 showed high ABTS+ radical scavenging and reducing power when encapsulated in SMs. In conclusion, the SMs-2 method emerged as an effective approach for producing efficient nanocarriers for EOs, signifying a promising path for future developments in antioxidant delivery systems.

Effect of cationic surfactant on the physicochemical and antibacterial properties of colloidal systems (emulsions and microemulsions)

Colloidal systems have been used to encapsulate, protect and release essential oils in mouthwashes. In this study, we investigated the effect of cetylpyridinium chloride (CPC) on the physicochemical properties and antimicrobial activity of oil-in-water colloidal systems containing tea tree oil (TTO) and the nonionic surfactant polysorbate 80. Our main aim was to evaluate whether CPC could improve the antimicrobial activity of TTO, since this activity is impaired when this essential oil is encapsulated with polysorbate 80. These systems were prepared with different amounts of TTO (0-0.5% w/w) and CPC (0-0.5% w/w), at a final concentration of 2% (w/w) polysorbate 80. Dynamic light scattering (DLS) results revealed the formation of oil-swollen micelles and oil droplets as a function of TTO concentration. Increases in CPC concentrations led to a reduction of around 88% in the mean diameter of oil-swollen micelles. Although this variation was of only 20% for the oil droplets, the samples appearance changed from turbid to transparent. The surface charge of colloidal structures was also markedly affected by the CPC as demonstrated by the transition in zeta potential from slightly negative to highly positive values. Electron paramagnetic resonance (EPR) studies showed that this transition is followed by significant increases in the fluidity of surfactant monolayer of both colloidal structures. The antimicrobial activity of colloidal systems was tested against a Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureaus) bacteria. Our results revealed that the inhibition of bacterial growth is observed for the same CPC concentration (0.05% w/w for E. coli and 0.3% w/w for S. aureus) regardless of TTO content. These findings suggest that TTO may not act as an active ingredient in polysorbate 80 containing mouthwashes.

Revisiting the significance of nano-vitamin D for food fortification and therapeutic application

OBJECTIVE

Vitamin D (a prohormone) is an important micronutrient required by the body for skeletal homeostasis and a range of non-skeletal actions. Calcitriol, the active form of vitamin D, regulates a variety of cellular and metabolic processes through both genomic and nongenomic pathways. Often prescribed for treating rickets and osteoporosis, vitamin D deficiency can exacerbate various other medical conditions.

SIGNIFICANCE, METHODS, AND RESULTS

Despite its multifunctional uses, the sensitivity of vitamin D makes formulating an efficient drug delivery system a challenging task, which is further complicated by its poor aqueous solubility. Enhancing the oral absorption of vitamin D is vital in utilizing its full efficacy. Recent developments in encapsulation and nanotechnology have shown promising results in overcoming these constraints.

CONCLUSION

This review thus offers an insight to adequately comprehend the mechanistic pharmacology of vitamin D, its pathophysiological role, and justification of its medical indications, along with the benefits of utilizing nanotechnology for vitamin D delivery.

α-Tocopherol-loaded multi-layer nanoemulsion using chitosan, and dextran sulfate: Cellular uptake, antioxidant activity, and in vitro bioaccessibility

The potential of multi-layer nanoemulsions (NEs) for improving the cellular uptake, antioxidant activity, and in vitro bioaccessibility of α-tocopherol (ToC) was examined. ToC-loaded multi-layer NEs were prepared using lecithin (primary-NEs, P-NEs), chitosan (secondary-NEs, S-NEs), and dextran sulfate (tertiary-NEs, T-NEs) as wall materials. The bioadhesion, cellular permeability, and uptake of the multi-layer NEs were significantly higher than that of the free coumarin 6 (C6). As a result of cellular uptake, the mean fluorescence intensity of T-NEs was the highest among the three types of multi-layer NEs and was 9.8-fold higher than that of free C6. The cellular antioxidant abilities of P-NEs, S-NEs, and T-NEs were 40, 45, and 50 %, respectively. Multi-layer nanoencapsulation sustains free fatty acid release after digestion. Moreover, the bioavailability of T-NEs exhibited a two-fold increase compared with that of the free ToC. These findings indicate that by multi-layer NEs using a layer-by-layer method, the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC can be improved. Furthermore, T-NEs using chitosan and dextran sulfate can potentially enhance the cellular uptake, in vitro bioaccessibility, and antioxidant activity of ToC. These findings would facilitate the application of multi-layer NEs for lipophilic bioactive compounds using biopolymers.

Optimization of vitamin B12 nano-emulsification and encapsulation using spontaneous emulsification

In this study, the use of low-energy methods for nanoemulsification of vitamin B12 was investigated to protect this bioactive substance. The effects of sunflower oil concentrations (4-8%), Tween 80 (8-16%), and vitamin B12 (5-15%) on the physicochemical properties of B12 nanoemulsion were evaluated using response surface methodology (RSM). The results indicated that the quadratic model was the most fitting model for experimental data. Optimization revealed that the optimal formulation contained 6.5% sunflower oil, 9.6% Tween 80, and 13% vitamin B12, resulting in maximum efficiency, viscosity, and vitamin B12 content, as well as minimum pH, turbidity, p-Anisidine index, particle size, and polydispersity index (PDI). Under optimal conditions, pH, viscosity, turbidity, efficiency, vitamin B12, p-Anisidine index, PDI, and particle size were 7.24, 17.0024 cp, 2.19, 51.98%, 5.54 ppm, 0.01, 0.34, and 322 nm, respectively. This study highlights the effectiveness of spontaneous emulsification as a carrier for the encapsulation of bioactive compounds.

Soy Protein Isolate-Chitosan Nanoparticle-Stabilized Pickering Emulsions: Stability and In Vitro Digestion for DHA

The purpose of the study was to investigate the stability and oral delivery of DHA-encapsulated Pickering emulsions stabilized by soy protein isolate-chitosan (SPI-CS) nanoparticles (SPI-CS Pickering emulsions) under various conditions and in the simulated gastrointestinal (GIT) model. The stability of DHA was characterized by the retention rate under storage, ionic strength, and thermal conditions. The oral delivery efficiency was characterized by the retention and release rate of DHA in the GIT model and cell viability and uptake in the Caco-2 model. The results showed that the content of DHA was above 90% in various conditions. The retention rate of DHA in Pickering emulsions containing various nanoparticle concentrations (1.5 and 3.5%) decreased to 80%, while passing through the mouth to the stomach, and DHA was released 26% in 1.5% Pickering emulsions, which was faster than that of 3.5% in the small intestine. After digestion, DHA Pickering emulsions proved to be nontoxic and effectively absorbed by cells. These findings helped to develop a novel delivery system for DHA.

Application of Physical-Chemical Approaches for Encapsulation of Active Substances in Pharmaceutical and Food Industries

BACKGROUND

Encapsulation is a valuable method used to protect active substances and enhance their physico-chemical properties. It can also be used as protection from unpleasant scents and flavors or adverse environmental conditions.

METHODS

In this comprehensive review, we highlight the methods commonly utilized in the food and pharmaceutical industries, along with recent applications of these methods.

RESULTS

Through an analysis of numerous articles published in the last decade, we summarize the key methods and physico-chemical properties that are frequently considered with encapsulation techniques.

CONCLUSION

Encapsulation has demonstrated effectiveness and versatility in multiple industries, such as food, nutraceutical, and pharmaceuticals. Moreover, the selection of appropriate encapsulation methods is critical for the effective encapsulation of specific active compounds. Therefore, constant efforts are being made to develop novel encapsulation methods and coating materials for better encapsulation efficiency and to improve properties for specific use.

Flavour encapsulation: A comparative analysis of relevant techniques, physiochemical characterisation, stability, and food applications

Flavour is an important component that impacts the quality and acceptability of new functional foods. However, most flavour substances are low molecular mass volatile compounds, and direct handling and control during processing and storage are made difficult due to susceptibility to evaporation, and poor stability in the presence of air, light, moisture and heat. Encapsulation in the form of micro and nano technology has been used to address this challenge, thereby promoting easier handling during processing and storage. Improved stability is achieved by trapping the active or core flavour substances in matrices that are referred to as wall or carrier materials. The latter serve as physical barriers that protect the flavour substances, and the interactions between carrier materials and flavour substances has been the focus of many studies. Moreover, recent evidence also suggests that enhanced bioavailability of flavour substances and their targeted delivery can be achieved by nanoencapsulation compared to microencapsulation due to smaller particle or droplet sizes. The objective of this paper is to review several relevant aspects of physical-mechanical and physicochemical techniques employed to stabilize flavour substances by encapsulation. A comparative analysis of the physiochemical characterization of encapsulates (particle size, surface morphology and rheology) and the main factors that impact the stability of encapsulated flavour substances will also be presented. Food applications as well as opportunities for future research are also highlighted.

Fortification by design: A rational approach to designing vitamin D delivery systems for foods and beverages

Over the past few decades, vitamin D deficiency has been recognized as a serious global public health challenge. The World Health Organization has recommended fortification of foods with vitamin D, but this is often challenging because of its low water solubility, poor chemical stability, and low bioavailability. Studies have shown that these challenges can be overcome by encapsulating vitamin D within well-designed delivery systems containing nanoscale or microscale particles. The characteristics of these particles, such as their composition, size, structure, interfacial properties, and charge, can be controlled to attain desired functionality for specific applications. Recently, there has been great interest in the design, production, and application of vitamin-D loaded delivery systems. Many of the delivery systems reported in the literature are unsuitable for widespread application due to the complexity and high costs of the processing operations required to fabricate them, or because they are incompatible with food matrices. In this article, the concept of "fortification by design" is introduced, which involves a systematic approach to the design, production, and testing of colloidal delivery systems for the encapsulation and fortification of oil-soluble vitamins, using vitamin D as a model. Initially, the challenges associated with the incorporation of vitamin D into foods and beverages are reviewed. The fortification by design concept is then described, which involves several steps: (i) selection of appropriate vitamin D form; (ii) selection of appropriate food matrix; (iii) identification of appropriate delivery system; (iv) identification of appropriate production method; (vii) establishment of appropriate testing procedures; and (viii) system optimization.

Impact of cooking on vitamin D3 and 25(OH)D3 content of pork products

Little is known regarding the impact of cooking on vitamin D content in pork, despite meat being a major contributor to vitamin D intakes. This paper investigated the effect of household cooking (pan-fry/roast/grill/sous-vide/sauté), on the vitamin D₃ and 25-hydroxyvitamin D₃ (25(OH)D₃) concentration/retention in pork loin, mince and sausages. We hypothesised that vitamin D concentrations would be higher in cooked vs raw pork, and retention would differ between products. Cooking significantly increased vitamin D₃ (+49 %) and 25(OH)D₃ (+33 %) concentrations. All cooked loin vitamin D₃ concentrations were significantly lower than mince/sausage. Vitamin D₃ retention was > 100 % for all samples (102-135 %), except sauté mince (99 %) which still did not differ significantly from 100 % retention. Sous-vide cooking resulted in the highest vitamin D₃ retention (135 %). Likely owing to water/fat loss, household cooking of pork results in favourable retention of vitamin D₃ and 25(OH)D₃. The type of pork product has greater influence than cooking method.

Effect of α-tocopherol on the oxidative stability of horse oil-in-water emulsion during storage

Horse oil-in-water (O/W) emulsions were prepared and α-tocopherol was added at 0, 100, 200, and 500 ppm (α-T0, α-T100, α-T200, α-T500) to enhance its oxidative stability. Mean particle diameters of the O/W emulsions were 243-299 nm. Zeta potential values increased with the addition of α-tocopherol; however, they decreased during storage at 40 °C for 30 days. Particle size distribution of the O/W emulsion with α-tocopherol remained the same as that of α-T0. For lipid oxidation, the peroxide values of α-T0 and α-T500 were greatly increased from 2.96 and 2.89 to 13.76 and 12.46 mmol/kg oil, respectively, after 30 days. The α-T100 and α-T200 maintained lower peroxide values than other emulsions. Thiobarbituric acid-reactive substance values of α-T0 and α-T500 were higher than those of α-T100 and α-T200. These results indicate that the addition of α-tocopherol from 100 to 200 ppm to the horse oil-in-water emulsion effectively improves its oxidative stability during storage.

pH-driven-assembled soy peptide nanoparticles as particulate emulsifier for oil-in-water Pickering emulsion and their potential for encapsulation of vitamin D3

Pickering emulsions prepared by food-grade particles have gained growing attention due to their promising application in functional food and pharmaceutical industries. In this study, we successfully fabricated soy peptide-based nanoparticles (SPN) through pH-driven process. Obtained particles with small particle size were surface active and shared intermediate wettability, and they could be well applied as an efficient particulate emulsifier for stabilizing oil-in-water Pickering emulsions at SPN concentration above 0.25 wt%. Furthermore, formed emulsions stabilized with SPN exhibited good protection towards Vitamin D₃ against UV irradiation and oxidative deterioration, where controlled release of Vitamin D₃in vitro could also be well achieved by modulating particle concentration. The whole process can contribute to a sustainable development of low-value peptide byproducts as functional food ingredients.

Intranasally administered melatonin core-shell polymeric nanocapsules: A promising treatment modality for cerebral ischemia

AIMS

The neurohormone melatonin (MEL) has been reported as a promising neuroprotective molecule, however it suffers pharmaceutical limitations such as poor solubility and low bioavailability, which hinder its pharmacological and clinical potential. In the current work, MEL was loaded in core-shell nanocarrier system; polymeric nanocapsules (PNCs), and assessed for its potential in cerebral ischemia reperfusion injury rat model when administered intranasally.

KEY FINDINGS

Adopting a D-optimal factorial design, MEL-PNCs were successfully formulated using the nanoprecipitation technique. MEL-PNCs exhibited a particle size ranging from 143.5 to 444 nm, negative zeta potential values ranging from -24.2 to -38.7 mV, cumulative release % for MEL ranging from 36.79 to 41.31 % over 8 h period, with overall good storage properties. The selected MEL-PNCs formulation displayed 8-fold higher permeation than the drug solution across sheep nasal mucosa. MEL-PNCs administered intranasally decreased oxidative stress and hippocampal inflammation, and the histological examination revealed the significant restoration of hippocampal neurons.

SIGNIFICANCE

MEL-PNCs administered intranasally could be a promising treatment modality in brain ischemia.

In vitro and in vivo evaluation of cinnamaldehyde Microemulsion-Mucus interaction

The current investigation explores the possible mechanism of the microemulsion drug delivery system to improve the oral bioavailability of cinnamaldehyde (CA), an important food spice, from the perspective of the microemulsion-mucus system. The cinnamaldehyde microemulsion (CA-ME) was prepared by the water titration method combined with the pseudo-ternary phase diagram. The dynamic analysis was applied to detect the drug release in vitro. An intestinal mucosal injury test was conducted to evaluate the safety of CA-ME and drug absorption across the intestinal tract of rats was investigated through an Ussing chamber system. The rheology of blank mucus and drug-loaded mucus was investigated using a rheometer. The bioavailability of CA-ME in rats was evaluated through pharmacokinetic characteristics. The ratio of optimal prescription was Tween 80: 1,2-propanediol: vitamin E oil: CA: water = 24.3:4.8:5:7.5:58.4. The droplets were uniform in size and evenly dispersed. Rheological studies showed that the microemulsion-mucus system all exhibit pseudoplastic fluid behavior, and CA-ME increased the viscosity of the mucus to a certain extent. Compared with CA solution, CA-ME promoted the absorption of CA in various intestinal segments, especially the ileum. Pharmacokinetic experiments showed that the relative bioavailability of CA-ME was enhanced 2.5-fold higher than that of CA solution. ME as a carrier for lipophobic substances, may increase the viscosity of the intestine mucus system to obtain longer residue time and better absorption. PRACTICAL APPLICATIONS: In this study, in vitro absorption Ussing model was combined with rheological and pharmacokinetic analysis to systematically analyze the intestinal mucus mechanism of microemulsion to improve the oral bioavailability of cinnamic aldehyde. It laid the foundation for exploring the absorption and transport of drugs in the intestinal mucus barrier.

Garlic essential oil-based nanoemulsion carrier: Release and stability kinetics of volatile components

An O/W nanoemulsion of garlic essential oil (GEO) at different oil‐to‐emulsion (O/E) ratios (5%, 10%, 15%, and 25%) was formulated to protect the volatile components of GEO. The effects of O/E ratios on the encapsulation efficiency (EE%) of volatile compounds and droplet size of nanoemulsions were studied. The results showed that with increasing in E/O ratio, droplet size increased while EE% decreased so that the droplet size was below 100 nm for all samples and the EE% was almost above 80% for most samples. The effects of various factors such as temperature (5°C–45°C), pH values (3–7), ionic strength (0–500 mM), and O/E ratios (5%–25%) on kinetic of nanoemulsions stability were studied. Reducing pH values and raising the temperature, ionic strength, and O/E ratios intensified the instability process and constant rate of instability in all nanoemulsions. The effects of temperature and O/E ratios on the release kinetics of volatile components were evaluated over time, and kinetic parameters such as release rate constant (k), Q10, and activation energy (Ea) were calculated in which results showed a zero‐degree model to describe the release kinetic behavior of most nanoemulsions. Both temperature and O/E ratios factors as well as their interaction (which had a synergistic effect) had a significant effect on increasing the release rate of volatiles so that the degree of reaction rate was changed from zero to the first order at simultaneous high levels of both factors. FT‐IR spectroscopy was carried out to study interactions among nanoemulsion ingredients. The presence of sulfur‐containing functional groups of garlic oil (thiosulphate, diallyl trisulfide, etc.) in nanoemulsions was confirmed by FT‐IR.

Preparation, Characterization, and Antioxidant Activity of Nanoemulsions Incorporating Lemon Essential Oil

Lemon essential oil (LEO) is a kind of citrus essential oil with antioxidant, anti-inflammatory, and antimicrobial activities, but low water solubility and biological instability hinder its industrial application. In this study, LEO was nanoemulsified to solve these problems. The preparation procedure of lemon essential oil nanoemulsions (LEO-NEs) was optimized, and the physicochemical characterization and antioxidant activities were explored. Single-factor experiments (SFEs) and response surface methodology (RSM) were conducted for the effects on the mean droplet size of LEO-NEs. Five factors of SFE which may influence the droplet size were identified: HLB value, concentration of essential oil, concentration of surfactant, ultrasonic power, and ultrasonic time. On the basis of the SFE, the RSM approach was used to optimize the preparation procedure to obtain LEO-NEs with the smallest droplet size. LEO-NEs exhibited good antioxidant activity when the HLB value was 13, content of surfactant was 0.157 g/mL, ultrasonic time was 23.50 min, and ultrasonic power was 761.65 W. In conclusion, these results can provide a good theoretical basis for the industrial application of lemon essential oil.

Optimisation of food grade mixed surfactant-based l-ascorbic acid nanoemulsions using response surface methodology

Co‐surfactant free l‐ascorbic acid (LAA) nanoemulsions were prepared using mixed surfactants (Soya lecithin and Tween 80). Response surface methodology (RSM) was used to optimise the emulsifying conditions for LAA nanoemulsions. The effects of water proportion (6%–14% w/w), homogenisation pressure (80–160 MPa), surfactant concentrations (4%–12% w/w) and laa concentration (0.5–1.3 w/w) on responses (size of droplets and nanoemulsion stability) were investigated. RSM results showed that the values of responses can be successfully predicted through second‐order polynomial model. The coefficients of determinations for droplet size and nanoemulsion stability were 0.9375 and 0.9027, respectively. The optimum preparation conditions for l‐LAA nanoemulsion were 9.04% water proportion, 114.48 MPa homogenisation pressure, 7.36% surfactant concentration and 1.09% LAA concentration. At the end of one month storage study, the retention of LAA in optimised nanoemulsions stored at 4°C and 25°C were 74.4% and 66.7%, respectively. These results may provide valuable contributions for food and pharmaceutical industry to develop delivery system for food additives and nutraceutical components.

Ultrasound-Assisted Microencapsulation of Soybean Oil and Vitamin D Using Bare Glycogen Nanoparticles

Ultrasonically synthesized core-shell microcapsules can be made of synthetic polymers or natural biopolymers, such as proteins and polysaccharides, and have found applications in food, drug delivery and cosmetics. This study reports on the ultrasonic synthesis of microcapsules using unmodified (natural) and biodegradable glycogen nanoparticles derived from various sources, such as rabbit and bovine liver, oyster and sweet corn, for the encapsulation of soybean oil and vitamin D. Depending on their source, glycogen nanoparticles exhibited differences in size and 'bound' proteins. We optimized various synthetic parameters, such as ultrasonic power, time and concentration of glycogens and the oil phase to obtain stable core-shell microcapsules. Particularly, under ultrasound-induced emulsification conditions (sonication time 45 s and sonication power 160 W), native glycogens formed microcapsules with diameter between 0.3 μm and 8 μm. It was found that the size of glycogen as well as the protein component play an important role in stabilizing the Pickering emulsion and the microcapsules shell. This study highlights that native glycogen nanoparticles without any further tedious chemical modification steps can be successfully used for the encapsulation of nutrients.

Simultaneous encapsulation of trans-resveratrol and vitamin D3 in highly concentrated double emulsions

BACKGROUND

Encapsulation of biocompounds is essential to protect them from environmental factors that could enhance their oxidation or cause them to lose their beneficial properties due to extreme photosensitivity, among other factors. The main goal of this work was to study the feasibility of preparing concentrated double emulsions with a high loading capacity containing simultaneously trans-resveratrol (RSV) and vitamin D₃ (VitD₃ ). Such emulsions could be used for food fortification or pharmaceutical formulations or as vehicles for targeted controlled release.

RESULTS

In order to achieve large concentrations of the encapsulated compounds, all the double emulsions were formulated using a W₁ /O in W₂ ratio of 80/20, while the ratios tested for W₁ in O where 20/80 and 30/70. All the emulsions were characterized by droplet size, morphology, colloidal stability and encapsulation efficiency (EE) over a period of 6 weeks. VitD₃ and RSV concentration were determined by a technique based on reverse-phase high-performance liquid chromatography. The viability of preparing concentrated W₁ /O/W₂ emulsions containing both biocompounds has been demonstrated with satisfactory results. Initial RSV concentrations in the concentrated double emulsions formulated varied from 5.0 to 8.3 mg L^-1 , while for VitD₃ values of 28-32 mg L^-1 were obtained. The presence of VitD₃ retarded RSV release in the formulated emulsions. It was observed that after 1 week of storage RSV EE increased around 10-50% when VitD₃ was simultaneously encapsulated.

CONCLUSION

Simultaneous encapsulation of RSV and VitD₃ was possible in high internal phase emulsions. The emulsions presented high colloidal stability, being suitable for food fortification applications. © 2020 Society of Chemical Industry.

Effect of temperature of preheated soy protein isolate on the structure and properties of soy protein isolate heated-vitamin D3 complex

In this paper, soy protein isolate (SPI) was preheated and combined with vitamin D₃ (VD₃ ) to study the protective effect of modified SPI on VD₃ . The structure and properties of the SPI with heat treatment-VD₃ (SPI(H)-VD₃ ) complex were determined. The secondary and tertiary structure of SPI(H)-VD₃ results showed that the content of α-helix decreased and the content of random coil increased, indicating that the rigid structure of the protein decreased, the flexibility increased, and the maximum fluorescence intensity wavelength was red shifted. When the heat treatment temperature was 85°C, the embedding rate of SPI(H)-VD₃ composite was the highest. As the heat treatment temperature increased, the internal hydrophobic groups of SPI were exposed, and the average particle size decreased significantly. The light stability results showed that the content of VD₃ in the SPI(H)-VD₃ composite at a heat treatment temperature of 85°C was significantly increased compared with the unheated SPI. PRACTICAL APPLICATIONS: This article mainly discusses the structure and properties of modified soy protein isolates bound to VD₃ by preheating soy protein isolates at different temperatures. It provides more possibilities for the application of VD₃ in food.

The Effect of Microfluidization Pressure and Tocopherol Content on the Retention of Vitamin A in Oil-In-Water Emulsions

This work investigates the oxidative stability of vitamin A encapsulated in oil-in-water emulsions, which were prepared by using a microfluidizer. All emulsions were prepared with a fixed content of vitamin A (525 µM), corn oil (10%), water (90%), and whey protein (2%), but varying two main factors: the microfluidizer pressure (10, 50, 100, 200 MPa) and the amount of α-tocopherol (0, 0.25, 0.50, 1.00 mg/g). The content of vitamin A before and after the microfluidization process, and during the subsequent five weeks of storage at 40 °C were determined by HPLC-DAD. The results of the analysis of variance performed either on the data obtained before and after the microfluidization process or during the storage showed that the highest stability of vitamin A was obtained with the highest content of α-tocopherol and with an applied pressure between 100 and 200 MPa. The highest stability was explained by the smaller particle size of the resulting oil droplets. However, high pressures (200 MPa) showed a negative effect on vitamin A retention. These results could be useful for future formulations of retinoids.

In vitro solubilization of fat-soluble vitamins in structurally defined mixed intestinal assemblies

The structures of fed state intestinal assemblies containing bile components, dietary fat, and fat-soluble vitamins are not well known, although they are involved in lipid transport. In this study, several methods were used to investigate structural transitions upon various dietary lipids or various fat-soluble vitamins incorporation in bile intestinal assemblies. In particular, DLS and turbidimetry were used to study transition points as a function of component concentration, and cryo-TEM and SAXS were used to resolve assembly structures at microscopic and supramolecular scales, respectively. Results showed that increasing the concentration of dietary lipids in bile assembly induced a transition from core-shell micelles to unilamellar vesicles (except with caprylate lipids, always yielding micelles). In these specific assemblies, increasing the concentration of a fat-soluble vitamin either induced a systematic structural transition, defining a solubilization capacity (α-tocopherol or phylloquinone), or induced a structural transition only in micelles (retinol), or did not induce any structural transition up to very high concentrations (cholecalciferol). Using SAXS data, ideal molecular organizations are proposed for assemblies in the absence or presence of α-tocopherol.

Vitamin D3 Loaded Niosomes and Transfersomes Produced by Ethanol Injection Method: Identification of the Critical Preparation Step for Size Control

Vesicular nanocarriers have an important role in drug delivery and dietary supplements. Size control and optimization of encapsulation efficiency (EE) should be optimized for those applications. In this work, we report on the identification of the crucial step (injection, evaporation, or sonication) innanovesicles (transfersomes and niosomes) preparation by theethanol injection method (EI). The identification of each production step on the final vesicle size was analyzed in order to optimize further scale-up process. Results indicated that the final size of transfersomeswas clearly influenced by the sonication step while the final size of niosomes was mainly governed by the injection step. Measurements of final surface tension of the different vesicular systems prepared indicate a linear positive tendency with the vesicle size formed. This relation could help to better understand the process and design a vesicular size prediction model for EI. Vitamin D3 (VitD3) was encapsulated in the systems formulated with encapsulation efficiencies larger than 90%. Interaction between the encapsulated compound and the membrane layer components is crucial for vesicle stability. This work has an impact on the scaling-up production of vesicles for further food science applications.

Encapsulation of Lipid-Soluble Bioactives by Nanoemulsions

Lipid-soluble bioactives are important nutrients in foods. However, their addition in food formulations, is often limited by limited solubility and high tendency for oxidation. Lipid-soluble bioactives, such as vitamins A, E, D and K, carotenoids, polyunsaturated fatty acids (PUFA) and essential oils are generally dispersed in water-based solutions by homogenization. Among the different homogenization technologies available, nanoemulsions are one of the most promising. Accordingly, this review aims to summarize the most recent advances in nanoemulsion technology for the encapsulation of lipid-soluble bioactives. Modern approaches for producing nanoemulsion systems will be discussed. In addition, the challenges on the encapsulation of common food ingredients, including the physical and chemical stability of the nanoemulsion systems, will be also critically examined.

4-n-Butylresorcinol-Based Linear and Graft Polymethacrylates for Arbutin and Vitamins Delivery by Micellar Systems

A novel initiator, bromoester modified 4-n-butylresorcinol (4nBREBr₂), was prepared and utilized in controlled atom transfer radical polymerization (ATRP) to obtain three series of amphiphilic copolymers. The V-shaped copolymers of methyl methacrylate (MMA), 2-hydroxyethyl methacrylate (HEMA), and poly(ethylene glycol) methyl ether methacrylate (MPEGMA), abbreviated to P(HEMA-co-MMA), P(HEMA-co-MPEGMA), and P(MMA-co-MPEGMA), were synthesized. Moreover, P((HEMA-graft-PEG)-co-MMA) graft copolymers were prepared by combining the pre-polymerization modification of HEMA and a "click" reaction using a "grafting onto" approach. All copolymers could form micelles with encapsulated active substances (vitamin C (VitC), vitamin E (VitE), arbutin (ARB)), which are used in cosmetology. In vitro studies carried out in a PBS solution (pH 7.4) demonstrates that in most cases the maximum release of active substance was after 1 h. The polymeric systems presenting satisfactory encapsulation characteristics and release profiles are attractive micellar carriers of cosmetic substances, which show a positive effect on the skin condition.

Vitamin D microencapsulation and fortification: Trends and technologies

Today, as per the latest medical reports available, majority of the population throughout globe is facing vitamin D (Vit D) deficiency. Even in sub-tropical countries like India and many others Vit D deficiency is highly prevalent despite the exuberant available sunshine (a major source of Vit D) throughtout the year. The reason could be attributed to an array of factors including socioeconomical, cultural and religious. Further, other than the sunlight, there are very limited sources of Vit D to fulfil the recommended dietary allowance of Vit D (RDA: 400-800 IU per day). A large proportion of Vit D is lost during food processing and storage due to environmental stress conditions such as temperature, pH, salt, oxygen and light. Vita D, an important micronutrient, is essentially required for the prevention of disorders such as neurodegenerative diseases, cardiovascular diseases, cancer etc. in addition to its traditional role in bone metabolism. Therefore, in order to meet the daily requirements of Vit D for human body, WHO has recognized fortification as the most efficient and safest method to address malnutrition. But there are innumerable chellenges involved during food fortification using Vit D as fortificants such as homogeneity into the food matrix, physico-chemical/photochemical degradation, loss during processing and storage, interactions with other components of food matrix resulting into change in taste, texture and appearance thus affecting acceptability, palatability and marketability. Fortification of Vit D into food products especially the ones which have an aqueous portion, is not simple for food technologist. Recent advances in nanotechnology offer various microencapsulation techniques such as liposome, solid-lipid particles, nanostructured lipid carriers, emulsion, spray drying etc. which have been used to design efficient nanomaterials with desired functionality and have great potential for fortification of fortificants like Vit D. The present review is an undate on Vit D, in light of its fortification level, RDA, factors affecting its bioavailability and various microencapsulation techniques adopted to develop Vit D-nanomaterials and their fate in food fortification.

Physicochemical characterization and antimicrobial activity in novel systems containing buriti oil and structured lipids nanoemulsions

Buriti oil nanoemulsions were prepared using non-interesterified buriti oil or buriti oil interesterified for 6 or 24 h (NBO, NBO6h, and NBO24 h), respectively. The aim was to investigate the effects of interesterified oils on the physicochemical and biological properties of nanoemulsions. Samples were stored at 4 and 25 °C for 30 days, and their physicochemical properties and biological activities were evaluated. The mean droplet diameter of nanoemulsions ranged from 196 to 270 nm. NBO24 h had the smallest droplet size and was the most stable during the storage period. Furthermore, NBO24 h demonstrating the good oxidative stability, had a high antioxidant capacity, and was less susceptible to droplet aggregation. NBO and NBO24 h had similar biological activity against Gram-negative bacteria (Escherichia coli O157: H7); bacterial growth was inhibited by at least 60% at 3.12 mg mL-1. The nanoemulsions have interesting properties for the production of pharmaceutical, cosmetic, and food formulations with antimicrobial activity.

Food-Grade Nanoemulsions: Preparation, Stability and Application in Encapsulation of Bioactive Compounds

Nanoemulsions have attracted significant attention in food fields and can increase the functionality of the bioactive compounds contained within them. In this paper, the preparation methods, including low-energy and high-energy methods, were first reviewed. Second, the physical and chemical destabilization mechanisms of nanoemulsions, such as gravitational separation (creaming or sedimentation), flocculation, coalescence, Ostwald ripening, lipid oxidation and so on, were reviewed. Then, the impact of different stabilizers, including emulsifiers, weighting agents, texture modifiers (thickening agents and gelling agents), ripening inhibitors, antioxidants and chelating agents, on the physicochemical stability of nanoemulsions were discussed. Finally, the applications of nanoemulsions for the delivery of functional ingredients, including bioactive lipids, essential oil, flavor compounds, vitamins, phenolic compounds and carotenoids, were summarized. This review can provide some reference for the selection of preparation methods and stabilizers that will improve performance in nanoemulsion-based products and expand their usage.

Fabrication of nano-structured lipid carrier for encapsulation of vitamin D3 for fortification of 'Lassi'; A milk based beverage

A phase inversion based cold water dilution method was developed to encapsulate Vitamin D₃ (Vit D) in nano-structured lipid carrier (NLC) by blending caprylic-/capric triglyceride, Leciva S70 and Kolliphor HS®15, Vit D and sodium chloride. To optimize the process; a total of forty one formulations prepared by varying in their composition were tested for presence of NLC. Out of forty one formulations, only thirteen formulations resulted in NLC formation which were further evaluated for their physico-chemical attributes (particle size, zeta potential, transmittance, encapsulation efficiency and Vit D release). During principal component analysis using XLstats it was found that NLC-19, fabricated with 20% (v/v) Kolliphor, 20% (v/v) CCTG and 60% (v/v) water, 2.5% (w/v) Leciva, 2% (w/v) Vit D and 5% (w/v) sodium chloride was the most suitable for purpose of encapsulating Vitamin D. Hence, NLC-19 formulation was further taken up for stability studies under the following environmental stress conditions: (a) Temperature and humidity: accelerated condition: 45 ± 2 °C and RH 75 ± 5%, ambient condition: 25 ± 3 °C and RH 65 ± 5% and refrigerated condition: 6 ± 2 °C and RH 55 ± 5%, (b) pH: 3, 4, 5, 6, and 7, and (c) Ionic strength (NaCl concentration): 0 mM, 250 mM, 500 mM and 750 mM. The sensory evaluation of 'Lassi' (fortified with NLC-19) and its acceptability further confirmed the suitability of NLC-19 for the purpose of fortification of Vitamin D₃ in 'Lassi' (A milk based beverage).

Drug Delivery Systems for Vitamin D Supplementation and Therapy

Vitamin D (VD) is a fat-soluble prohormone well known for its role in regulating calcium and phosphate metabolism. It has been clinically used for many years to prevent rickets in children, osteomalacia, and osteoporosis in adults. VD insufficiency is a common medical condition, and many supplements are available in the market in order to increase serum 25-hydroxy VD levels to recommended amounts. Over the course of the last decades, it has become increasingly clear that calcitriol, an active form of VD, regulates multiple cellular processes with effects on normal and malignant cell growth and differentiation, and on the immune and cardiovascular function. Increasing evidence supports the role of the VD system in cancer prevention and therapy. Due to many pleiotropic and beneficial effects in extra-skeletal disorders, VD has gained potential and become an interesting active for encapsulation into drug delivery systems. The purpose of this review is to present the diversity of drug delivery systems that have been reported for VD or VD derivatives in an orderly manner across the following categories: Oral administration, application on the skin, cancer prevention/therapy, and other diseases or routes of administration.

A phase inversion based nanoemulsion fabrication process to encapsulate vitamin D3 for food applications

A phase inversion based nanoemulsion fabrication process was developed to encapsulate vitamin D₃ by blending caprylic-/capric triglyceride (CCTG), Leciva S70, Kolliphor® HS 15, vitamin D₃ and aqueous phase (sodium chloride solution). In order to find out nanoparticle formation zone (NFZ), a ternary diagram was plotted with 41 possible combinations of three components CCTG, Kolliphor® HS 15 and aqueous phase. Out of forty one, only twelve combinations resulted in formation of stable nanoemulsion where the composition varied between 10%-40% (v/v), 10%-25% (v/v) and 35%-80% (v/v) for Kolliphor, CCTG and water respectively. Further, these 12 nanoemulsions were investigated for their particle size, zeta potential, emulsion stability, encapsulation efficiency and release kinetics (simulated digestion) of vitamin D. The nanoemulsion (NE-20) fabricated with 30% (v/v) Kolliphor, 20% (v/v) CCTG and 50% (v/v) aqueous phase was found to be the most suitable with respected to zeta potential, emulsion stability and encapsulation efficiency and also demonstrated high bioavailability of vitamin D as compared to other combinations and hence was selected for further physiochemical studies. The selected nanoemulsion was also investigated for particle size and zeta potential and stability of vitamin D₃ retention under different environmental stress conditions (i) temperature and humidity: (a) accelerated condition: 45 ± 2 °C and RH 75 ± 5%, (b) ambient condition: 25 ± 3 °C and RH 65 ± 5% and (c) refrigerated condition: 6 ± 2 °C and RH 55 ± 5% (ii) pH (3-7) under refrigerated condition and (iii) ionic strength: NaCl concentration (0 mM, 250 mM, 500 mM and 750 mM) under crefrigerated condition. Fourier transform infrared spectroscopy and High Perfomance Liquid Chromatograpy technique were used to study physico-chemical stability of encapsulated vitamin D₃ in the developed nanoemulsion. The sensory evaluation also indicated the acceptability of the selected nanoemulsion the purpose of fortification for beverages.

Improved Stability of Polyglycerol Polyricinoleate-Substituted Nanostructured Lipid Carrier Cholecalciferol Emulsions with Different Carrier Oils

Cholecalciferol, also known as vitamin D₃ , is a recognized therapeutic agent for treatment of bone diseases and cancer. However, instability and poor bioavailability have been major challenges for delivering Vitamin D₃ . The objective of this study was to formulate improved nanostructured lipid carrier (NLC) vitamin D₃ emulsions. We tested the effect of different carrier oils and the use of a solid lipid nanoparticle emulsifier, polyglycerol polyricinoleate (PGPR) on the stability of the vitamin D₃ emulsions. In contrast to the control that used glyceryl monostearate (GMS) the PGPR substitution resulted in relatively small particle sizes (0.30 to 0.43 μm), with high absolute value of zeta potentials (39.5 to 67.8 mV) and high encapsulation efficiency (85.2% to 90.4%). The stability of the NLC emulsions against environmental stresses was evaluated under varying conditions of ionic strength, pH, freeze-thaw cycles, and storage at different temperatures. Although NLC emulsions were stable at high ionic strengths, they were found to be unstable at low pH (<3), which led to aggregation and coalescence of emulsion droplets. In case of freeze-thaw stress, although relatively stable compared to control NLC, the PGPR substituted groups exhibited a slight increase in particle size and a decrease in zeta potential when the cycle was repeated five times. Additionally, we found that PGPR-substituted emulsions showed higher liquid dispersion stability than controls at 25 and 65 °C. Thus, we have formulated a modified NLC vitamin D₃ emulsion that can be widely used in the food industry. PRACTICAL APPLICATION: Vitamin D₃ , an essential micronutrient, is often added as supplements in food products and beverages for added health benefits. However, the stability of vitamin D₃ emulsions that are used in the preparation of such products has been a major concern. We have developed a modified emulsion that has improved stability against environmental stresses. We believe, in future, this formulation can be efficiently used in the food industry.

Solid lipid nanoparticles as carriers for lipophilic compounds for applications in foods

Nanotechnology is a new subject of interest in the field of food industry. Therefore, scientific and technological studies have been intensified in the last 10 years because of the promising results associated with the potential application of functional properties in food products, such as physical and chemical stability, protection and controlled release of bioactive compounds, and facilitated solubility of lipophilic compounds. Lipids have been used as raw material for the preparation of nanostructures, mainly owing to the solubilization capacity of lipophilic bioactive compounds, as well as because of the advantage of potentially using natural ingredients for production on an industrial scale. Thus, in this review, we describe the information reported in scientific literature on the chemical, physical, and structural properties of lipids used in the preparation of solid lipid nanoparticles (SLNs) and nanostructured lipid carriers (NLCs). We reviewed the production methods; structural lipid components; emulsifying systems; bioactive lipophilic compounds; and the physical, thermal, and oxidative properties of SLN and NLC. In addition, important methods for characterizing these systems with regard to particle size, polydispersity index, zeta potential, morphology, crystallization behavior, and polymorphism are discussed with examples, in order to support studies that consider physical stability during processing and storage. Furthermore, studies on the applications of SLNs and NLCs in foods are only found for model systems, justifying the compilation of a series of studies on the potential applications to encourage future works. In addition, we have described the aspects still under discussion, related to the possible risks and regulatory aspects of nanotechnology in food.

Low-Energy Encapsulation of α-Tocopherol Using Fully Food Grade Oil-in-Water Microemulsions

Encapsulation of active agents, such as vitamins and antioxidants, is one of the possibilities that allow their incorporation in beverages, food, or in pharmaceutical products. Simultaneously, encapsulation protects these active agents from oxidation, producing more stable active compounds. Formation of nanodroplets by spontaneously formed microemulsion (ME) offers, on one hand, a low-energy technology of encapsulation and, on the other hand, because of a small size of the droplets, it assures long-term stability even in harsher environments. In this study, oil-in-water MEs allowed the low-energy encapsulation of α-tocopherol (αToc) into an aqueous medium with the aid of fully food-grade ingredients, using isoamyl acetate as the dispersed oil phase, which was selected between three different types of oils. Both cosurfactant-free and cosurfactant-holder ME systems were formulated, in which Tween 20 and glycerol were employed as the surfactant and the cosurfactant, respectively. The ME monophasic area was determined through the construction of pseudoternary phase diagrams. The encapsulated αToc within 10-20 nm nanocapsules showed radical scavenging activity dependent on the encapsulated amount of αToc, as it was demonstrated by electron paramagnetic resonance spectroscopy. The radical scavenging activity slightly increased within the time investigated, indicating a slow release of the active compound from the nanodroplets, which is a promising result for their application, especially in pharmaceuticals.