Double emulsions as potential fat replacers with gallic acid and quercetin nanoemulsions in the aqueous phases

Bioaccessibility of chlorogenic acid and curcumin co-encapsulated in double emulsions with the inner interface stabilized by functionalized silica nanoparticles

The aim of this study was to evaluate the bioaccessibility of chlorogenic acid (CA) and curcumin co-encapsulated in Pickering double emulsions (DEs) with the inner interface stabilized by hydrophobically modified silica nanoparticles with myristic acid (SNPs-C14) or tocopherol succinate (SNPs-TS). Both SNPs-C14 and SNPs-TS showed contact angles > 90°. Pickering W1/O emulsions were formulated with 4 % of both types of SNPs. Pickering DEs showed higher creaming stability (5-7 %, day 42) and higher CA encapsulation efficiency (EE; 80 %) than control DE. The EE of curcumin was > 98 % in all the DEs. CA was steadily released from Pickering DEs during digestion, achieving bioaccessibility values of 58-60 %. Curcumin was released during the intestinal phase (∼80 % bioaccessibility in all DEs). Co-loaded DEs showed similar bioaccessibility for CA and curcumin than single-loaded. SNPs-C14 and SNPs-TS were suitable to stabilize the W1:O interface of DEs as co-delivery systems of bioactive compounds with health-promoting properties.

High internal phase double emulsions stabilized by modified pea protein-alginate complexes: Application for co-encapsulation of riboflavin and β-carotene

The application of many hydrophilic and hydrophobic nutraceuticals is limited by their poor solubility, chemical stability, and/or bioaccessibility. In this study, a novel Pickering high internal phase double emulsion co-stabilized by modified pea protein isolate (PPI) and sodium alginate (SA) was developed for the co-encapsulation of model hydrophilic (riboflavin) and hydrophobic (β-carotene) nutraceuticals. Initially, the effect of emulsifier type in the external water phase on emulsion formation and stability was examined, including commercial PPI (C-PPI), C-PPI-SA complex, homogenized and ultrasonicated PPI (HU-PPI), and HU-PPI-SA complex. The encapsulation and protective effects of these double emulsions on hydrophilic riboflavin and hydrophobic β-carotene were then evaluated. The results demonstrated that the thermal and storage stabilities of the double emulsion formulated from HU-PPI-SA were high, which was attributed to the formation of a thick biopolymer coating around the oil droplets, as well as thickening of the aqueous phase. Encapsulation significantly improved the photostability of the two nutraceuticals. The double emulsion formulated from HU-PPI-SA significantly improved the in vitro bioaccessibility of β-carotene, which was mainly attributed to inhibition of its chemical degradation under simulated acidic gastric conditions. The novel delivery system may therefore be used for the development of functional foods containing multiple nutraceuticals.

Fabrication and characterization of anthocyanin-loaded double Pickering emulsions stabilized by β-cyclodextrin

Anthocyanins, one of the important water-soluble pigments, are sensitive to environmental factors, which limits the application of anthocyanins in food field. In order to overcome this limitation, double Pickering emulsions stabilized by β-cyclodextrin were developed. The optimum preparation conditions of the emulsions were determined firstly and the performance and structure of emulsions were investigated. Results showed that the optimum preparation conditions of emulsions were the ratio of (W1/O): W2 = 6:4 and 4 % β-cyclodextrin concentration. Optical microscope and confocal laser scanning microscope results confirmed that β-cyclodextrin adsorbed onto the surface of droplets forming stable double Pickering emulsions structure. In vitro gastrointestinal digestion experiments proved that double Pickering emulsions played a controlled-release effect in the small intestine. Rheological analysis proved that the emulsions exhibited elastic properties and demonstrated shear thinning behavior. The emulsions showed excellent stability under centrifugation and thermal conditions. These findings will promote anthocyanins' application in daily diet.

Dietary gallic acid as an antioxidant: A review of its food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions

Gallic acid (GA), a dietary phenolic acid with potent antioxidant activity, is widely distributed in edible plants. GA has been applied in the food industry as an antimicrobial agent, food fresh-keeping agent, oil stabilizer, active food wrap material, and food processing stabilizer. GA is a potential dietary supplement due to its health benefits on various functional disorders associated with oxidative stress, including renal, neurological, hepatic, pulmonary, reproductive, and cardiovascular diseases. GA is rapidly absorbed and metabolized after oral administration, resulting in low bioavailability, which is susceptible to various factors, such as intestinal microbiota, transporters, and metabolism of galloyl derivatives. GA exhibits a tendency to distribute primarily to the kidney, liver, heart, and brain. A total of 37 metabolites of GA has been identified, and decarboxylation and dihydroxylation in phase I metabolism and sulfation, glucuronidation, and methylation in phase Ⅱ metabolism are considered the main in vivo biotransformation pathways of GA. Different types of nanocarriers, such as polymeric nanoparticles, dendrimers, and nanodots, have been successfully developed to enhance the health-promoting function of GA by increasing bioavailability. GA may induce drug interactions with conventional drugs, such as hydroxyurea, linagliptin, and diltiazem, due to its inhibitory effects on metabolic enzymes, including cytochrome P450 3A4 and 2D6, and transporters, including P-glycoprotein, breast cancer resistance protein, and organic anion-transporting polypeptide 1B3. In conclusion, in-depth studies of GA on food industry applications, health benefits, bioavailability, nano-delivery systems, and drug interactions have laid the foundation for its comprehensive application as a food additive and dietary supplement.

An Updated Comprehensive Overview of Different Food Applications of W1/O/W2 and O1/W/O2 Double Emulsions

Double emulsions (DEs) present promising applications as alternatives to conventional emulsions in the pharmaceutical, cosmetic, and food industries. However, most review articles have focused on the formulation, preparation approaches, physical stability, and release profile of encapsulants based on DEs, particularly water-in-oil-in-water (W1/O/W2), with less attention paid to specific food applications. Therefore, this review offers updated detailed research advances in potential food applications of both W1/O/W2 and oil-in-water-in-oil (O1/W/O2) DEs over the past decade. To this end, various food-relevant applications of DEs in the fortification; preservation (antioxidant and antimicrobial targets); encapsulation of enzymes; delivery and protection of probiotics; color stability; the masking of unpleasant tastes and odors; the development of healthy foods with low levels of fat, sugar, and salt; and design of novel edible packaging are discussed and their functional properties and release characteristics during storage and digestion are highlighted.

Quantification of the Quercetin Nanoemulsion Technique Using Various Parameters

Natural antioxidant polyphenolic compounds obtained from different plants are considered antioxidants for curing various chronic pathological diseases such as cardiovascular disorders and cancer. Quercetin (a polyphenolic flavonol) has attracted much attention from dietitians and medicinal chemists due to its wide variety of pharmacological activities, including anti-diabetic, anti-hypertensive, anti-carcinogenic, anti-asthmatic, anti-viral, and antioxidant activities. Furthermore, structurally, it is well suited to stabilize emulsions. The present review depicts the important role of the quercetin nanoemulsion technique, used to enhance the solubility of target materials both in vivo and in vitro as well as to decrease the risk of degradation and metabolism of drugs. Researchers have used cryo-TEM to study the morphology of quercetin nanoemulsions. The effects of various parameters such as pH, salts, and solvent concentration on quercetin nanoemulsion have been investigated for quercetin nanoemulsion. Many studies have used UV–Vis spectroscopy and HPLC for the characterization of these particles such as solubility, stability, and encapsulating efficiency.

Oxidation and oxidative stability in emulsions

Emulsions are implemented in the fabrication of a wide array of foods and therefore are of great importance in food science. However, the application of emulsions in food production is restricted by two main obstacles, that is, physical and oxidative stability. The former has been comprehensively reviewed somewhere else, but our literature review indicated that there is a prominent ground for reviewing the latter across all kinds of emulsions. Therefore, the present study was formulated in order to review oxidation and oxidative stability in emulsions. In doing so, different measures to render oxidative stability to emulsions are reviewed after introducing lipid oxidation reactions and methods to measure lipid oxidation. These strategies are scrutinized in four main categories, namely storage conditions, emulsifiers, optimization of production methods, and antioxidants. Afterward, oxidation in all types of emulsions, including conventional ones (oil-in-water and water-in-oil) and uncommon emulsions in food production (oil-in-oil), is reviewed. Furthermore, the oxidation and oxidative stability of multiple emulsions, nanoemulsions, and Pickering emulsions are taken into account. Finally, oxidative processes across different parent and food emulsions were explained taking a comparative approach.

Physicochemical properties of kashk supplemented with encapsulated lemongrass extract

Kashk is a perishable fermented dairy product. Since chemical preservatives are harmful for human health, we aimed to study lemongrass (Cymbopogon citratus L.) as a natural preservative. First, we assessed the phytochemical properties of lemongrass extract. Then, we added lemongrass extract and microencapsulated lemongrass extract to kashk samples. Finally, we analyzed their physicochemical and sensorial properties during 60 days of storage. Catechin (419.04 ± 0.07 mg/L), gallic acid (319.67 ± 0.03 mg/L), and chloregenic acid (4.190 ± 0.002 mg/L) were found to be the predominant phenolic constituents in lemongrass. Total phenolics, total flavonoids, and antioxidant activity (IC50) values of the lemongrass extract were 26.73 mg GA/g, 8.06 mg Quercetin/g, and 2751.331 mg/L, respectively. The beads were spherical in shape with a 35.03-nm average particle diameter and 47.81% microencapsulation efficiency. The pH of the supplemented kashks decreased during the storage time. They showed lower acid degree values than the control at the end of storage. The peroxide, p-anisidine, and thiobarbituric acid values of the sample fortified with microencapsulated lemongrass extract were 6.15, 4.76, and 44.12%, respectively, being the lowest among the samples. This kashk sample had the highest hardness (570.62 ± 21.87 g), adhesiveness (18.10 ± 4.36 mJ), and cohesiveness (0.56 ± 0.25) but the lowest chewiness (72.66 ± 3.08 mJ) among the samples. It also had a better sensory profile than the control samples. Our results indicated that microencapsulated lemongrass extract could be incorporated into kashk to ensure suitable sensorial and textural properties. Furthermore, it may delay fat oxidation and lipolysis during storage.

Fabrication and Characterization of the Egg-White Protein Chitosan Double-Layer Emulsion

Egg-white protein has an abundance of hydrophobic amino acids and could be a potential emulsifier after modification. Here, egg-white protein was modified via ultrasonic and transglutaminase treatments to destroy the globular structure. The egg-white protein gel particles (EWP-GPs) were prepared and then a novel highly stable EWP-chitosan double-layer emulsion was constructed. When ultrasonic treatment was applied at 240 W and TGase (20 U/g EWP) treatment, the EWP-GPs had a low particle size and good emulsification performance. The particle size of EWP-GPs was a minimum of 287 nm, and the polymer dispersity index (PDI) was 0.41. The three-phase contact angle (θ_o/w) of EWP-GPs was 79.6° (lower than 90°), performing with good wettability. Based on these results, the EWP-chitosan double-layer emulsion was prepared through the EWP-GPs being treated with 240 W ultrasound, TGase, and chitosan in this study. When the double-layer emulsion had 0.6% (v/v) chitosan, the zeta potential of the double-layer emulsion was -1.1 mV and the double-layer emulsion had a small particle size (56.87 µm). The creaming index of double-layer emulsion at 0.6% (v/v) chitosan was 16.3% and the droplets were dispersed uniformly. According to the rheological results, the storage modulus (G') was larger than the loss modulus (G″) in the whole frequency, indicating the formation of an elastic gel network structure in the emulsion. It is hoped to develop a novel food-grade stabilizer and a stable double-layer emulsion, providing new environment-friendly processing in hen egg products and delivery systems.

Fabrication and Characterization of W/O/W Emulgels by Sipunculus nudus Salt-Soluble Proteins: Co-Encapsulation of Vitamin C and β-Carotene

W/O/W emulsions can be used to encapsulate both hydrophobic and hydrophilic bioactive as nutritional products. However, studies on protein stabilized gel-like W/O/W emulsions have rarely been reported, compared to the liquid state multiple emulsions. The purpose of this study was to investigate the effect of different oil–water ratios on the stability of W/O/W emulgels fabricated with salt-soluble proteins (SSPs) of Sipunculus nudus. The physical stability, structural characteristics, rheological properties, and encapsulation stability of vitamin C and β-carotene of double emulgels were investigated. The addition of W/O primary emulsion was determined to be 10% after the characterization of the morphology of double emulsion. The results of microstructure and rheological properties showed that the stability of W/O/W emulgels increased with the increasing concentration of SSPs. Additionally, the encapsulation efficiency of vitamin C and β-carotene were more than 87%, and 99%, respectively, and still could maintain around 50% retention of the antioxidant capacity after storage for 28 days at 4 °C. The aforementioned findings demonstrate that stable W/O/W emulgels are a viable option for active ingredients with an improvement in shelf stability and protection of functional activity.

Triggered and controlled release of bioactives in food applications

Bioactive compounds (e.g., nutraceuticals, micronutrients, antimicrobial, antioxidant) are added to food products and formulations to enhance sensorial/nutritional attributes and/or shelf-life. Many of these bioactives are susceptible to degradation when exposed to environmental and processing factors. Others involve in undesirable interactions with food constituents. Encapsulation is a useful tool for addressing these issues through various stabilization mechanisms. Besides protection, another important requirement of encapsulation is to design a carrier that predictably releases the encapsulated bioactive at the target site to elicit its intended functionality. To this end, controlled release carrier systems derived from interactive materials have been developed and commercially exploited to meet the requirements of various applications. This chapter provides an overview on basic controlled and triggered release concepts relevant to food and active packaging applications. Different approaches to encapsulate bioactive compounds and their mode of release are presented, from simple blending with a compatible matrix to complex multiphase carrier systems. To further elucidate the mass transport processes, selected diffusion and empirical release kinetic models are presented, along with their brief historical significance. Finally, interactive carriers that are responsive to moisture, pH, thermal and chemical stimuli are presented to illustrate how these triggered release mechanisms can be useful for food applications.

Enhancement of the Stability of Encapsulated Pomegranate (Punica granatum L.) Peel Extract by Double Emulsion with Carboxymethyl Cellulose

Pomegranate peel enriched with high value of bioactive phenolics with valuable health benefits. However, after extraction of the phenolic compounds, diverse factors can affect their stability. Therefore, we, herein, aimed to prepare W1/O/W2 double nanoemulsions loaded with phenolic-rich extract from pomegranate peel in the W1 phase. Double emulsions were fabricate during a two-step emulsification technique. Furthermore, the influence of sodium carboxymethyl cellulose (CMC) in the outer aqueous phase was also investigated. We found that W1/O/W2 emulsions containing phenolic-rich extract showed good physical stability, especially in the particle size, polydispersity index, zeta potential, and creaming index. Intriguingly, high encapsulation rates of pomegranate polyphenols >95% were achieved; however, emulsion with CMC had the best encapsulation stability during storage. Thus, our study provides helpful information about the double nanoemulsions delivery system for polyphenols generated from pomegranate peel, which may lead to the development of innovative polyphenol-enriched functional foods.

Encapsulation of Pomegranate Peel Extract (Punica granatum L.) by Double Emulsions: Effect of the Encapsulation Method and Oil Phase

Pomegranate peel is an agro-industrial waste that can be used as source of punicalagin, a polyphenolic compound with several beneficial effects on health. Since, once extracted, punicalagin is prone to degradation, its encapsulation by double emulsions can be an alternative to protect the active compound and control its release. The aim of this investigation was to evaluate the feasibility of encapsulating pomegranate peel extract (PPE) in double emulsions using different types of oils (castor, soybean, sunflower, Miglyol and orange) in a ratio of 70:30 (oil:PPE) and emulsification methods (direct membrane emulsification and mechanical agitation), using polyglycerol polyricinoleate (PGPR) and Tween 80 as lipophilic and hydrophilic emulsifiers, respectively. Direct membrane emulsification (DME) led to more stable emulsions during storage. Droplet size, span values, morphology and encapsulation efficiency (EE) were better for double emulsions (DEs) prepared by DME than for mechanical agitation (MA). DEs formulated using Miglyol or sunflower oil as the oily phase could be considered as suitable food grade systems to encapsulate punicalagin with concentrations up to 11,000 mg/L of PPE.

Fabrication and Characterization of Gel Beads of Whey Isolate Protein-Pectin Complex for Loading Quercetin and Their Digestion Release

In this study, emulsion gel beads for loading quercetin were prepared through an emulsification/gelation process using whey protein isolate (WPI) and pectin. Emulsion gel beads’ properties were investigated by different pectin content. Additionally, the physicochemical properties, morphology and quercetin release properties from beads were explored. Firstly, electrical characteristics and the rheology of bead-forming solutions were measured, revealing that all systems had strong negative charge and exhibited shear-thinning behavior. The textural results demonstrated that the properties of emulsion gel beads were improved with increasing the content of pectin. It was also confirmed that crosslinking was formed between WPI emulsion and pectin by Fourier Transform Infrared (FTIR) analysis and thermogravimetric analysis (TGA). In addition, the shape of the beads was spherical or ellipses with smooth surfaces and they had a tight gel network of internal structures, which was visualized by using electron microscopy (SEM). Finally, the amount of quercetin released in vitro was gradually decreased with increasing pectin content; it was as low as 0.59%. These results revealed that WPI emulsion–pectin gel beads might be an effective delivery system for quercetin as a colon target and are worth exploring further.

Effect of black chokeberry pomace extract incorporation on the physical and oxidative stability of water-in-oil-in-water emulsion

BACKGROUND

Despite the obvious benefits of double emulsions in reducing fat content by replacing it with the water phase, their physical and oxidative stability remains a major concern. The objective of this study was to determine the ability of black chokeberry extract to inhibit lipid oxidation during storage at 4 °C for 60 days when different amounts of the extract were added to the inner water phase of the double emulsion. In the first step, the physical stability of the emulsions was evaluated.

RESULTS

Higher amount of the extract caused the formation of double emulsions with smaller droplets and higher viscosity. Throughout the whole storage period, the double emulsions showed good physical stability and high encapsulation efficiency (EE) of the extract (>95%) in the inner water phase. The positive effect of the extract on the oxidative stability of the double emulsions was shown by measuring changes in peroxide values and conjugated dienes and through the Oxipres and Rancimat tests during the convenient and accelerated storage of emulsions for 60 days.

CONCLUSION

The higher amount of extract suppressed lipid oxidation to a higher extent given the significant amount of polyphenolics in the extract. © 2021 Society of Chemical Industry.

Enhancement of bioavailability and bioactivity of diet-derived flavonoids by application of nanotechnology: a review

Flavonoids, which are a class of polyphenols widely existing in food and medicine, have enormous pharmacological effects. The functional properties of flavonoids are mainly distributed to their anti-oxidative, anticancer, and anti-inflammatoryeffects, etc. However, flavonoids' low bioavailability limits their clinical application, which is closely related to their intestinal absorption and metabolism. In addition, because of the short residence time of oral bioactive molecules in the stomach, low permeability and low solubility in the gastrointestinal tract, flavonoids are easy to be decomposed by the external environment and gastrointestinal tract after digestion. To tackle these obstacles, technological approaches like microencapsulation have been developed and applied for the formulation of flavonoid-enriched food products. In the light of these scientific advances, the objective of this review is to establish the structural requirements of flavonoids for appreciable anticancer, anti-inflammatory, and antioxidant effects, and elucidate a comprehensive mechanism that can explain their activity. Furthermore, the novelty in application of nanotechnology for the safe delivery of flavonoids in food matrices is discussed. After a literature on the flavonoids and their health attributes, the encapsulation methods and the coating materials are presented.

Grape seed proanthocyanidin-loaded gel-like W/O/W emulsion stabilized by genipin-crosslinked alkaline soluble polysaccharides-whey protein isolate conjugates: Fabrication, stability, and in vitro digestion

The present work aims to fabricate the genipin-crosslinked alkaline soluble polysaccharides-whey protein isolate conjugates (G-AWC) to stabilize W/O/W emulsions for encapsulation and delivery of grape seed proanthocyanidins (GSP). After crosslinking reaction, the molecular weight was increased and surface hydrophobicity was decreased. Then, the G-AWC and polyglycerol polyricinoleate (PGPR, a lipophilic emulsifier) were employed to prepare a GSP-loaded W/O/W emulsion with the addition of gelatin and sucrose in W₁ phase via a two-step procedure. Creamed emulsion could be fabricated at W₁/O volume fraction (Φ) of 10%-70% and further increased Φ to 75% or even up to 90% could obtain gel-like emulsion with notably elastic behaviors. In the W₁/O/W₂ emulsion with Φ of 80%, the encapsulation efficiency (EE) of GSP reached up to 95.86%, and decreased by ca. 10% after a week of storage. Moreover, the encapsulated GSP in the emulsion showed a remarkably higher bioaccessibility (40.72%) compared to free GSP (13.11%) in the simulated gastrointestinal digestion. These results indicated that G-AWC-stabilized W/O/W emulsions could be an effective carrier to encapsulate water-soluble bioactive compounds with enhanced stability and bioaccessibility.

Application of Advanced Emulsion Technology in the Food Industry: A Review and Critical Evaluation

The food industry is one of the major users of emulsion technology, as many food products exist in an emulsified form, including many dressings, sauces, spreads, dips, creams, and beverages. Recently, there has been an interest in improving the healthiness, sustainability, and safety of foods in an attempt to address some of the negative effects associated with the modern food supply, such as rising chronic diseases, environmental damage, and food safety concerns. Advanced emulsion technologies can be used to address many of these concerns. In this review article, recent studies on the development and utilization of these advanced technologies are critically assessed, including nanoemulsions, high internal phase emulsions (HIPEs), Pickering emulsions, multilayer emulsions, solid lipid nanoparticles (SLNs), multiple emulsions, and emulgels. A brief description of each type of emulsion is given, then their formation and properties are described, and finally their potential applications in the food industry are presented. Special emphasis is given to the utilization of these advanced technologies for the delivery of bioactive compounds.

A composite chitosan derivative nanoparticle to stabilize a W1/O/W2 emulsion: Preparation and characterization

For preparing stable water-in-oil-in-water emulsion, the role of nanoparticles in stabilizing the interface is very important. In this study, chitosan hydrochloride-carboxymethyl chitosan (CHC-CMC) nanoparticles were prepared considering electrostatic interactions; then the emulsion was prepared and the stability characteristics in presence of NaCl (0-200 mmol/L) and 30 d storage were studied. CHC-CMC nanoparticles (261 nm) were obtained when the CHC: CMC ratio was 1:2. CHC-CMC formation was verified by FT-IR when a new peak appeared at 1580 cm^-1; W₂ contained 2 wt % CHC-CMC and W₁ contained 1 wt % sodium alginate, the creaming index (81.6 %) was higher for the emulsions than Tween 80 (67.4 %) after 30 d. Confocal laser scanning microscopy confirmed the double microstructures, in contrast to the collapse with Tween 80, because the CHC-CMC nanoparticles were densely adsorbing on the oil-water interface. This indicates that CHC-CMC has a stronger ability to stabilize W₁/O/W₂ emulsion than Tween 80.

Stabilization of water-in-oil emulsion of Pulicaria jaubertii extract by ultrasonication: Fabrication, characterization, and storage stability

This study investigated the effect of ultrasonic treatments on the properties and stability of the water-in-oil (W/O) emulsion of Pulicaria jaubertii (PJ) extract. The study used different ultrasound powers (0, 100, 200, 400, and 600 W) at two storage degrees (4 and 25 °C) for 28 days. The findings showed that the emulsifying properties were improved to different extents after ultrasonic treatments. The treatment at 600 W showed optimum particle size, polydispersity index, emulsifying property, viscosity properties, and release of total phenolic content than the other powers. However, the ultrasonic power of 400 W gave positive effects on creaming index and antioxidant release compared to 600 W. The emulsion stored at 4 °C presented higher stability than that stored at 25 °C during the 28 days of storage. Microscopically, the increase in sonication power up to 600 W reduced particle size and decreased flocculation, thus resulted in stable emulsions, which is desirable for its applications in food systems.

Encapsulation Preserves Antioxidant and Antidiabetic Activities of Cactus Acid Fruit Bioactive Compounds under Simulated Digestion Conditions

Cactus acid fruit (Xoconostle) has been studied due its content of bioactive compounds. Traditional Mexican medicine attributes hypoglycemic, hypocholesterolemic, anti-inflammatory, antiulcerogenic and immunostimulant properties among others. The bioactive compounds contained in xoconostle have shown their ability to inhibit digestive enzymes such as α-amylase and α-glucosidase. Unfortunately, polyphenols and antioxidants in general are molecules susceptible to degradation due to storage conditions, (temperature, oxygen and light) or the gastrointestinal tract, which limits its activity and compromises its potential beneficial effect on health. The objectives of this work were to evaluate the stability, antioxidant and antidiabetic activity of encapsulated extract of xoconostle within double emulsions (water-in-oil-in-water) during storage conditions and simulated digestion. Total phenols, flavonoids, betalains, antioxidant activity, α-amylase and α-glucosidase inhibition were measured before and after the preparation of double emulsions and during the simulation of digestion. The ED40% (treatment with 40% of xoconostle extract) treatment showed the highest percentage of inhibition of α-glucosidase in all phases of digestion. The inhibitory activity of α-amylase and α-glucosidase related to antidiabetic activity was higher in microencapsulated extracts than the non-encapsulated extracts. These results confirm the viability of encapsulation systems based on double emulsions to encapsulate and protect natural antidiabetic compounds.

Freeze-drying of black chokeberry pomace extract-loaded double emulsions to obtain dispersible powders

Black chokeberry pomace extract is rich in polyphenolic antioxidants, including anthocyanins. Added to foods, bioactive compounds of the extract can undergo undesirable changes both during food handling and digestion. In this study, we examined the possibility of encapsulating a considerable amount of black chokeberry pomace extract in the inner water phase of double emulsion (water-in-oil-in-water), for intended use in food applications. Furthermore, this study investigated the feasibility of double emulsions loaded with the extract for freeze-drying to obtain dispersible powders. A substantial amount (2.1%) of black chokeberry pomace extract was efficiently encapsulated in the inner water phase of double emulsion and remained entrapped during 60 days of storage (<97%) as well as during the freeze-drying of emulsions. Reconstituted emulsions obtained after the rehydration process were found to show monomodal droplet size distribution, decent creaming stability (approximately 97%), and good encapsulation efficiency (95.36%). Such characteristics of powdered double emulsions loaded by black chokeberry pomace extract make them suitable for food application as retainer and preservative of bioactive polyphenolic-rich extracts. PRACTICAL APPLICATION: Powders of double emulsions loaded by black chokeberry pomace extract could be used as a source of bioactive polyphenolic compounds.

Influence of gelation on the retention of purple cactus pear extract in microencapsulated double emulsions

A purple cactus pear (Opuntia ficus-indica) extract (CP) was encapsulated in double emulsions (DE) gelled with gelatin (DE-CP-G) and with gelatin and transglutaminase (DE-CP-GT), as well as in a DE with a liquid external aqueous phase (DE-CP), in order to study the retention of betanin as colorant agent. Both gelled DEs showed a predominantly elastic behavior, in contrast with DE-CP. The degradation rate constant of betanin was significantly higher in DE-CP-GT (90.2 x 10⁻³ days^-1) than in DE-CP-G (11.0 x 10⁻³ days^-1) and DE-CP (14.6 x 10⁻³ days^-1) during cold-storage (4 °C). A shift towards yellow color was found in all the systems during cold-storage (4 °C) and after thermal treatment (70°C/30 min), especially in DE-CP-GT, denoting a higher degradation of betanin. Betalamic acid, cyclo-Dopa 5-O-β-glucoside, 17-decarboxy-betanin and neobetanin were identified by UHPLC-MS/MS as degradation products of betanin.

Enhancing the potential preclinical and clinical benefits of quercetin through novel drug delivery systems

Quercetin is reported to have numerous pharmacological actions, including antidiabetic, anti-inflammatory and anticancer activities. The main mechanism responsible for its pharmacological activities is its ability to quench reactive oxygen species (ROS) and, hence, decrease the oxidative stress responsible for the development of various diseases. Despite its proven therapeutic potential, the clinical use of quercetin remains limited because of its low aqueous solubility, bioavailability, and substantial first-pass metabolism. To overcome this, several novel formulations have been reported. In this review, we focus on the applications of quercetin extract as well as its novel formulations for treating different disorders. We also examine its proposed mechanism of action of quercetin.

Solid Self-Emulsifying Delivery System (S-SEDS) of Dihydromyricetin: A New Way for Preparing Functional Food

The present study was aimed at formulating and evaluating a novel solid self-emulsifying delivery system (S-SEDS) for the application in functional foods of dihydromyricetin (DMY). First, solubility study and pseudo-ternary phase diagram analysis were adopted to optimize the formulation of liquid self-emulsifying delivery system (L-SEDS). And the thermodynamic stable L-SEDS with 5% content of DMY was fabricated and further developed into a solid form via vacuum rotary evaporation with Aerosil 300 as the solid adsorbent. Solid state characterization of the S-SEDS was performed by scanning electron microscopy, Fourier-transform infrared spectroscopy, and X-ray powder diffraction. Furthermore, studies proved that the antioxidant activity and bioaccessibility of DMY were improved after incorporated into S-SEDS formulation compared to pure DMY. The S-SEDS showed good resistance against various storage conditions investigated for 10 weeks. PRACTICAL APPLICATION: Solid self-emulsifying delivery system (S-SEDS) combined the advantages of liquid self-emulsifying delivery system with those of a solid dosage form to overcome the disadvantages associated with liquid formulations is more convenient for storage and transportation in practical application. Furthermore, the technology of producing S-SEDS is simple and can be realized in industrial production. Hence, S-SEDS could be a promising strategy to overcome the poor water solubility and short biological half-life of dihydromyricetin for further application in functional foods and beverage industry.

Double emulsions with olive leaves extract as fat replacers in meat systems with high oxidative stability

Double emulsions (DE) with a healthy oil blend as lipid phase and an olive leave extract (OLE) encapsulated in the internal aqueous phase (DE/OLE) were incorporated as fat replacers in meat systems, in order to improve both the lipid profile and the oxidative stability. After 14 days of storage at 4 °C, DE/OLE showed good physical stability (90% of globule population was still below 10 μm diameter), and high antioxidant capacity (over 80%), longer than time required for this type of food ingredients. A high correlation was found between the remaining oleuropein content and the antioxidant capacity in both meat systems with DE/OLE (MS-DE/OLE) and meat systems with the oil blend as liquid oil and non-encapsulated OLE (MS-L/OLE). MS-DE/OLE were technologically feasible and showed higher retention of oleuropein (69%), oxidative stability and antioxidant capacity at 60 °C for 7 days than MS-L/OLE, where oleuropein was almost depleted. The encapsulation of OLE in DE could be a suitable strategy to avoid lipid oxidation in meat systems with healthier lipid profile.

Coencapsulation of Polyphenols and Anthocyanins from Blueberry Pomace by Double Emulsion Stabilized by Whey Proteins: Effect of Homogenization Parameters

Blueberry pomace is a rich source of high-value bioactive polyphenols with presumed health benefits. Their incorporation into functional foods and health-related products benefits from coencapsulation and protection of polyphenol-rich extracts in suitable carriers. This study aimed to create a water-in-oil-in-water (W₁/O/W₂) double emulsion system suitable for the coencapsulation of total phenolics (TP) and anthocyanins (TA) from a polyphenol-rich extract of blueberry pomace (W₁). The effect of critical physical parameters for preparing stable double emulsions, namely homogenization pressure, stirring speed and time, was investigated by measuring the hydrodynamic diameter, size dispersity and zeta potential of the oil droplets, and the encapsulation efficiency of TP and TA. The oil droplets were negatively charged (negative zeta potential values), which was related to the pH and composition of W₂ (whey protein isolate solution) and suggests stabilization by the charged whey proteins. Increasing W₁/O/W₂ microfluidization pressure from 50 to 200 MPa or homogenization speed from 6000 to 12,000 rpm significantly increased droplet diameter and zeta potential and decreased TA and TP encapsulation efficiency. Increasing W₁/O/W₂ homogenization time from 15 to 20 min also increased droplet diameter and zeta potential and lowered TA encapsulation efficiency, while TP encapsulation did not vary significantly. In contrast, increasing W₁/O homogenization time from 5 to 10 min at 10,000 rpm markedly increased TA encapsulation efficiency and reduced droplet diameter and zeta potential. High coencapsulation rates of blueberry polyphenols and anthocyanins around 80% or greater were achieved when the oil droplets were relatively small (mean diameter < 400 nm), with low dispersity (<0.25) and a high negative surface charge (-40 mV or less). These characteristics were obtained by homogenizing for 10 min at 10,000 rpm (W₁/O), then 6000 rpm for 15 min, followed by microfluidization at 50 MPa.