Influence of whey protein-xanthan gum stabilized emulsion on stability and in vitro digestibility of encapsulated astaxanthin

Influence of gelatinized octenyl succinic anhydride-modified waxy adlay seed starch on the properties of astaxanthin-loaded emulsions: Emulsion properties, stability and in vitro digestion properties

Octenyl succinic anhydride (OSA)-modified starch is a commonly used food emulsifier and its emulsifying properties are positively correlated with the degree of substitution (DS). However, the maximum concentration of OSA in starch approved by the FDA and the China National Food Safety Standards is 3%. This study aims to enhance the emulsifying properties of OSA-modified waxy adlay seed starch by gelatinization under a limited DS and investigate its use in preparing delivery systems. The gelatinized OSA starch exhibited a more flexible macromolecular structure and better emulsifying activity (20.19 m2/g). The gelatinized OSA starch-stabilized astaxanthin-loaded emulsions showed high retention of astaxanthin (>50%) and long-term stability (56 days). In vitro digestion, the emulsion system showed a protective effect on astaxanthin, and the bioaccessibility of astaxanthin was increased to 16.32%. This study indicated that gelatinization could enhance the emulsifying properties of OSA starch, and this starch-stabilized emulsion was an effective system for astaxanthin.

Revealing the potential effects of oil phase on the stability and bioavailability of astaxanthin contained in Pickering emulsions: In vivo, in vitro and molecular dynamics simulation analysis

This study investigated the effects of oil phases on the encapsulation rate, storage stability, and bioavailability of astaxanthin (ASTA) in Pickering emulsions (PEs). Results showed PEs of mixed oils (olive oil/edible tea oil) had excellent encapsulation efficiency (about 96.0%) and storage stability of ASTA. In vitro simulated gastrointestinal digestion results showed the mixed oil PE with a smaller interfacial area and higher monounsaturated fatty acid content may play a better role in improving ASTA retention and bioaccessibility. In vivo absorption results confirmed the mixed oil PE with an olive oil/edible tea oil of 7:3 was more favorable for ASTA absorption. Molecular dynamics simulation showed ASTA bound more strongly and stably to fatty acid molecules in the system of olive oil/edible tea oil of 7:3; and van der Waals force was the main binding force. NMR further proved there really were interactions between ASTA and four main fatty acids.

A Review of Whey Protein-Based Bioactive Delivery Systems: Design, Fabrication, and Application

The efficacy of many edible bioactive agents is limited by their low water dispersibility and chemical instability in foods, as well as by their poor bioaccessibility, low absorption, and metabolism within the human gastrointestinal tract. Whey proteins are amphiphilic molecules that can be used to construct a variety of edible carrier systems that can improve the performance of bioactive ingredients. These carrier systems are being used by the food and biomedical industries to encapsulate, protect, and deliver a variety of bioactive agents. In this article, we begin by providing an overview of the molecular and functional characteristics of whey proteins, and then discuss their interactions with various kinds of bioactive agents. The ability of whey proteins to be used as building blocks to assemble different kinds of carrier systems is then discussed, including nanoparticles, hydrogels, oleogels, bigels, nanofibers, nanotubes, and nanoemulsions. Moreover, applications of these carrier systems are highlighted. Different kinds of whey protein-based carriers can be used to encapsulate, protect, and deliver bioactive agents. Each kind of carrier has its own characteristics, which make them suitable for different application needs in foods and other products. Previous studies suggest that whey protein-based carriers are particularly suitable for protecting chemically labile bioactive agents and for prolonging their release profiles. In the future, it is likely that the applications of whey protein-based carriers in the food and pharmaceutical fields will expand.

Docosahexaenoic acid-mediated milk protein treated by ultrasound-assisted pH shifting for enhanced astaxanthin delivery and processed cheese application

Whey protein isolate (WPI)-based nanodelivery systems have recently attracted an increasing amount of attention. Despite this, research focusing on milk protein concentrate (MPC) and micellar casein (MCC) as carriers loaded in hydrophobic compounds is lacking. This study investigated the mediated effect of docosahexaenoic acid (DHA) in 3 different milk proteins for the embedding of astaxanthin (ASTA) after ultrasound-assisted pH-shifting treatment. We then evaluated the application of milk protein carriers in cheese processing by comparing MPC, MCC, and WPI. The particle size, polydispersity index, and zeta potential results of the milk protein-DHA complex suggested that the addition of 0.36 μmol/mL DHA optimized the delivery of milk protein to ASTA. All 3 DHA-mediated milk proteins induced an improvement in encapsulation efficiency and antioxidant properties of ASTA. Furthermore, the DHA-mediated MPC and MCC played a stronger role in improving the bioaccessibility and thermal and storage stability of ASTA than those without DHA. Tests conducted to examine the application in cheese production indicated that MCC carrier had a positive effect on the texture of cheeses. However, the delivery effect was dependent on the milk protein variety, and MCC exhibited the best protection ability of ASTA, followed by MPC and WPI. The simulated digestion and storage stability results of cheese further confirmed that the protein encapsulation mediated by DHA was more conducive to ASTA absorption. These findings suggested that the DHA-mediated milk protein complexes studied here may be suitable hydrophilic delivery carriers for the hydrophobic nutrient ASTA, potentially playing different roles in improving its storage stability and bioaccessibility.

The evaluation of mixed-layer emulsions stabilized by myofibrillar protein-chitosan complex for delivering astaxanthin: Fabrication, characterization, stability and in vitro digestibility

Muscle protein based functional foods have been attracted great interests in novel food designing. Herein, myofibrillar protein (MP)-chitosan (CH) electrostatic complexes were employed to fabricate mixed-layer emulsions to protect and deliver astaxanthin. The MP/CH complex fabricated mixed-layer emulsions displayed higher stability against pH and temperature changes, exhibiting smaller droplet and homogenous distributions. After UV-light irradiation for 8 h, the mixed-layer emulsions had higher astaxanthin retention (69.11 %, 1:1 group). During storage, a lower degree of lipid oxidation, protein oxidation and higher astaxanthin retention were obtained, indicating desirable protections of mixed-layer emulsions. The vitro digestion reveled the mixed-layer emulsions could decrease the release of free fatty acids. Meanwhile, the bioaccessibility of astaxanthin was higher (30.43 %, 2:1 group) than monolayer emulsion. In all, the MP/CH prepared mixed-layer emulsions could protect and deliver fat-soluble bioactive compounds, and contributed to develop muscle protein based functional foods to meet the needs of slow and controlled release.

Impact of cod skin peptide-ι-carrageenan conjugates prepared via the Maillard reaction on the physical and oxidative stability of Antarctic krill oil emulsions

This research aimed to construct an emulsifier by the Maillard reaction at various times using cod fish skin collagen peptide (CSCP) and ι-carrageenan (ι-car) to stabilize an Antarctic krill oil (AKO) emulsion. This emulsion was then investigated for physicochemical stability, oxidative stability, and gastrointestinal digestibility. The emulsion stability index and emulsifying activity index of Maillard reaction products (MRPs) were increased by 36.32 % and 66.30 %, respectively, at the appropriate graft degree (25.58 %) compared with the mixture of ι-car and CSCP. In vitro digestibility suggested the higher release of free fatty acids (FFAs) of 10d-MRPs-AKO-emulsion, and the highest bioavailability of AST in 10d-MRPs-AKO was found to be 28.48 %. The findings of this study showed the potential of MRPs to improve peptide function, serve as delivery vehicles for bioactive chemicals, and possibly serve as a valuable emulsifier to be used in the food industry.

Fabricating oleic acid-ovalbumin complexes using an ultrasonic-coupled weakly alkaline pH technique: Improving the dispersibility, stability, and bioaccessibility of lutein in water

This study constructed a self-assembly non-covalent oleic acid (OA) and ovalbumin (OVA) complex via an ultrasonic coupled pH-driven approach to simultaneously improve the water dispersibility, stability, and bioaccessibility of lutein (LUT). The results showed that homogeneous, stable hydrophilic OA-OVA particles were obtained in optimized conditions (an OVA concentration of 4.0 mg/mL, pH 9.0, ultrasonic conditions of 200 W for 2 min, and OA-OVA molar ratios of 2:1-20:1), with the LUT encapsulation efficiency (EE) exceeding 88.9%. Furthermore, Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) confirmed complete LUT encapsulation in the OA-OVA particles, displaying spherical particle formation with smooth surfaces. The OA-OVA complexes effectively improved the thermal and storage stability of LUT and significantly enhanced its bioaccessibility. These findings suggest that fatty acid-protein complexes may have potential application value as carotenoid delivery vectors.

New Horizons in Probiotics: Unraveling the Potential of Edible Microbial Polysaccharides through In Vitro Digestion Models

In vitro digestion models, as innovative assessment tools, possess advantages such as speed, high throughput, low cost, and high repeatability. They have been widely applied to the investigation of food digestion behavior and its potential impact on health. In recent years, research on edible polysaccharides in the field of intestinal health has been increasing. However, there is still a lack of systematic reviews on the application of microbial-derived edible polysaccharides in in vitro intestinal models. This review thoroughly discusses the limitations and challenges of static and dynamic in vitro digestion experiments, while providing an in-depth introduction to several typical in vitro digestion models. In light of this, we focus on the degradability of microbial polysaccharides and oligosaccharides, with a particular emphasis on edible microbial polysaccharides typically utilized in the food industry, such as xanthan gum and gellan gum, and their potential impacts on intestinal health. Through this review, a more comprehensive understanding of the latest developments in microbial polysaccharides, regarding probiotic delivery, immobilization, and probiotic potential, is expected, thus providing an expanded and deepened perspective for their application in functional foods.

Astaxanthin encapsulation in soybean protein isolate-sodium alginate complexes-stabilized nanoemulsions: antioxidant activities, environmental stability, and in vitro digestibility

BACKGROUND

Nanoemulsions (NEs) have been considered an effective carrier to protect environmentally labile bioactive compounds from degradation during food processing. Among the numerous types of NEs, biopolymer-stabilized NEs have gained much attention to achieve this function because of the extensive sources, biocompatibility, and tunability. Therefore, the antioxidant activities, environmental stability, and in vitro digestibility of astaxanthin (AST)-loaded soybean protein isolate (SPI)-alginate (SA) complexes-stabilized NEs (AST-SPI-SA-NEs) were investigated in this study.

RESULTS

The AST-SPI-SA-NEs exhibited an encapsulation efficiency of 88.30 ± 1.67%, which is greater than that of the AST-loaded SPI-stabilized NEs (AST-SPI-NEs) (77.31 ± 0.83%). Both AST-SPI-SA-NEs and AST-SPI-NEs exhibited significantly stronger hydroxyl or diphenylpicryl-hydrazyl radical-scavenging activities than the free AST. The formation of SPI-SA complexes strengthened the thermal, light, and storage stability of AST-SPI-SA-NEs with no apparently increasing mean diameter (around 200 nm). AST-SPI-SA-NEs also exhibited a better freeze-thaw dispersibility behavior than AST-SPI-NEs. AST-SPI-SA-NEs were more stable than AST-SPI-NEs were under in vitro gastrointestinal digestion conditions and exhibited a greater bioaccessibility (47.92 ± 0.42%) than both AST-SPI-NEs (12.97 ± 1.33%) and free AST (7.87 ± 0.37%). Hydrogen bonding was confirmed to participate in the formation of AST-SPI-SA-NEs and AST-SPI-NEs based on the molecular docking results.

CONCLUSIONS

The construction of SPI-SA-NEs is conducive to the encapsulation, protection, and absorption of AST, providing a promising method for broadening the application of AST in processed foods or developing novel ingredients of functional foods. © 2023 Society of Chemical Industry.

Modifications of whey proteins for emulsion based applications: Current status, issues and prospectives

Whey proteins are a major group of dairy proteins with high potential for various food based applications. Whey protein isolate has a limited range of functionalities. This functional range can be expanded using diverse modification methods to suit specific applications. This review summarizes the recent advances in the modifications of whey proteins using chemical, physical, and enzymatic methods and their combinations as well as the modification effects on the physicochemical properties. The uses of these modified whey proteins in emulsion based food and beverage systems are described. The limitations in the studies summarized are critically discussed, while future research directions are suggested on how to better utilize whey proteins for emulsion based uses through modifications.

Valorisation of prawn/shrimp shell waste through the production of biologically active components for functional food purposes

BACKGROUND

The aim of the work was to develop a technology for using waste from prawn and shrimp processing as a source of active ingredients that could be used in the promotion of healthy foods. From fresh and freeze-dried prawn and shrimp shells, protein hydrolysates (carotenoproteins) were obtained using two different enzymes, Flavourzyme and Protamex.

RESULTS

The obtained hydrolysates were characterised in terms of protein content, degree of hydrolysis, and antioxidant and antimicrobial activity. The hydrolysate with the best antioxidant properties (FRAP value of 2933.33 μmol L-1 TE; ORAC value of 115.58 μmol L-1 TE) was selected and tested for its possible use as a component of functional foods. Molecular weight distribution, amino acid profile and free amino acids, the solubility of the hydrolysate in different pH ranges as well as foaming ability were determined. It was found that this hydrolysate was characterised by an amino acid profile with high nutritional value, flavour enhancement properties and excellent solubility in a wide pH range (from 97.06% to 100%). Afterward, the possibility of using carotenoproteins from prawn waste as a component of an emulsion with furcellaran and a lipid preparation of astaxanthin, taken from post-hydrolysate production waste, was investigated. The obtained complexes were stable as proved by the measurement of zeta potential (ζ = -23.87 and -22.32 to -27.79 mV).

CONCLUSION

It is possible to produce stable complexes of the hydrolysate with furcellaran and to emulsify a lipid preparation of astaxanthin, obtained from waste following production of the hydrolysate, in them. © 2023 Society of Chemical Industry.

Comparison of milk protein concentrate, micellar casein, and whey protein isolate in loading astaxanthin after the treatment of ultrasound-assisted pH shifting

Milk proteins can be used as encapsulation walls to increase the bioavailability of active compounds because they can bind hydrophobic, hydrophilic, and charged compounds. The objective of this study was to investigate the effects of astaxanthin (ASTA) encapsulation and the functional properties of milk protein and ASTA nanocomposites by an ultrasound-assisted pH-shifting treatment of different milk proteins, including milk protein concentrate (MPC), micellar casein (MCC), and whey protein isolate (WPI). The ultrasound-assisted pH-shifting treatment of milk protein helped to improve the encapsulation rate of ASTA. Therein, MCC showed great improvement of encapsulating ASTA after co-treatment with the raised encapsulated rate of 5.11%, followed by WPI and MPC. Furthermore, the nanocomposites of ASTA with milk protein exhibit improved bioavailability, antioxidant capacity, and storage stability. By comparison, MCC-encapsulated ASTA has the best storage stability, followed by MPC, and WPI-encapsulated ASTA has the least stability over a 28-d storage period. The results of intrinsic fluorescence and surface hydrophobicity showed that milk protein underwent fluorescence quenching after binding to ASTA, which was due to the hydrophobic sites of the protein being occupied by ASTA. In general, the nanocomposites of milk protein and ASTA fabricated by using an ultrasound-assisted pH-shifting treatment have the potential to be better nano-delivery systems for ASTA in functional foods, especially MCC, which showed excellent performance in encapsulation after treatment technique.

Fabrication and characterization of dihydromyricetin-loaded microcapsules stabilized by glyceryl monostearate and whey protein-xanthan gum

Dihydromyricetin (DMY) is a lipophilic nutrient with various potential health benefits; however, its poor storage stability and low solubility and bioavailability limit its applications. This study aims to encapsulate DMY in microcapsules by membrane emulsification and freeze-drying methods to overcome these issues. Glyceryl monostearate (GMS, solid lipid) and octyl and decyl glycerate (ODO, liquid lipid) were applied as the inner cores. Whey protein and xanthan gum (XG) were used as wall materials. The prepared microcapsules had an irregular blocky aggregated structure with rough surfaces. All the microcapsules had a DMY loading of 0.85 %-1.1 % and encapsulation efficiency (EE) >85 %. GMS and XG increased the DMY loading and EE. The addition of GMS and an increased XG concentration led to a decrease in the rehydration rate. The in vitro release and digestion studies revealed that GMS and XG controlled the release and digestion of DMY. The chemical stability results indicated that GMS and XG protected DMY against oxidation. An antioxidant capacity study showed that GMS and XG helped DMY in the microcapsules exert antioxidant effects. This research study provides a platform for designing microcapsules with good stability and high bioavailability to deliver lipophilic bioactive compounds.

Antioxidant stability and in vitro digestion of β-carotene-loaded oil-in-water emulsions stabilized by whey protein isolate-Mesona chinensis polysaccharide conjugates

The aim of this study was to investigate the delivery of functional factor β-carotene by emulsion stabilized with whey protein isolate-Mesona chinensis polysaccharide (WPI-MCP) conjugate. Results showed that the WPI-MCP complex had better antioxidant properties than WPI. Correspondingly, the emulsions stabilized by this complex also had better oxidative stability compared with protein emulsions alone. The particle size of WPI-MCP emulsion was smaller and had a better stability when MCP was added at 0.2 % (w/v). The sizes of WPI-MCP and WPI emulsions were 3594.33 and 7765.67 nm at pH 4, indicating improved emulsion stability around isoelectric point of WPI. At different NaCl concentrations, the absolute values of zeta-potential of WPI-MCP emulsions were larger than that of WPI emulsions except 0.1 % (mol/L) NaCl. The sizes of WPI and WPI-MCP emulsions were 2384.32 and 790.12 nm, respectively. During in vitro digestion, WPI-MCP stabilized emulsions slowed down the release of free fatty acids and achieved about 80 % bioaccessibility of β-carotene, indicating that WPI-MCP-stabilized emulsions encapsulating β-carotene can effectively control the release of bioactive substances. These studies have potential significance and value for the construction of food-grade emulsion delivery system.

Compartmentalization of lutein in simple and double emulsions containing protein nanoparticles: Effects on stability and bioaccessibility

Delivery systems designed through protein stabilized emulsions are promising for incorporating carotenoids in different products. Nevertheless, the versatility in structures of such systems raises questions regarding the effect of the bioactive compound localization on their bio-efficacy, in particular for double emulsions. In this context, the aims of this study were to determine the impact of the localization of lutein in different water/oil/water double emulsions versus a single oil/water emulsion on the stability and in vitro bioaccessibility of lutein, a lipophilic carotenoid. The inner aqueous phase, which contained whey protein isolate (WPI) nanoparticles obtained by desolvation, was emulsified in sunflower oil stabilized by polyglycerol polyricinoleate (PGPR). The primary emulsion was then emulsified in a continuous aqueous phase containing whey protein isolate (WPI) and xanthan gum, the latter to increase the viscosity of the outer phase and delay creaming. Lutein was incorporated using different strategies: (1) lutein entrapped by WPI nanoparticles within the inner water phase of a double emulsion (W-L/O/W); (2) lutein incorporated into the oil phase of the double emulsion (W/O-L/W); (3) lutein incorporated in the oil phase of a single emulsion (O-L/W). All systems contained similar whey protein concentrations, as well as all other stabilizers. W-L/O/W sample showed the lowest lutein stability against light exposure during storage, and the highest lutein bioaccessibility after in vitro digestion, for freshly made samples. Furthermore, the in vitro bioaccessibility of lutein incorporated into the single emulsion was considerably lower than those observed for the double emulsions. The results reinforce the importance of designing appropriate structures for delivering improved stability and bioaccessibility of bioactive compounds.

Microfluidics potential for developing food-grade microstructures through emulsification processes and their application

The food sector continues to face challenges in developing techniques to increase the bioavailability of bioactive chemicals. Utilising microstructures capable of encapsulating diverse compounds has been proposed as a technological solution for their transport both in food and into the gastrointestinal tract. The present review discusses the primary elements that influence the emulsification process in microfluidic systems to form different microstructures for food applications. In microfluidic systems, reactions occur within small reaction channels (1-1000 μm), using small amounts of samples and reactants, ca. 102-103 times less than conventional assays. This geometry provides several advantages for emulsion and encapsulating structure production, like less waste generation, lower cost and gentle assays. Also, from a food application perspective, it allows the decrease in particle dispersion, resulting in a highly repeatable and efficient synthesis method that also improves the palatability of the food products into which the encapsulates are incorporated. However, it also entails some particular requirements. It is important to obtain a low Reynolds number (Re < approx. 250) for greater precision in droplet formation. Also, microfluidics requires fluid viscosity typically between 0.3 and 1400 mPa s at 20 °C. So, it is a challenge to find food-grade fluids that can operate at the micro-scale of these systems. Microfluidic systems can be used to synthesise different food-grade microstructures: microemulsions, solid lipid microparticles, microgels, or self-assembled structures like liposomes, niosomes, or polymersomes. Besides, microfluidics is particularly useful for accurately encapsulating bacterial cells to control their delivery and release on the action site. However, despite the significant advancement in these systems' development over the past several years, developing and implementing these systems on an industrial scale remains challenging for the food industry.

Ultrasonic-Assisted Extraction of Astaxanthin from Shrimp By-Products Using Vegetable Oils

BACKGROUND

The use of conventional astaxanthin extraction methods, typically involving organic solvents, leads to a heightened environmental impact. The aim of this study was to explore the potential use of environmentally friendly extraction solvents, such as vegetable oils, for recovering the shrimp by-product astaxanthin.

METHODS

Ultrasound-assisted extraction (UAE) in vegetable oils, including olive oil (OO), sunflower oil (SO), and flaxseed oil (FO), was employed to extract astaxanthin. The astaxanthin antioxidant activity was evaluated using an ABTS assay, and a mixture of gum Arabic and soy lecithin was used to form coacervates to produce astaxanthin encapsulation.

RESULTS

A by-product-vegetable oil ratio of 1:60, extraction time of 210 min, 60% amplitude of the extraction process, and the use of OO as the extracting medium resulted in an astaxanthin yield of 235 ± 4.07 μg astaxanthin/g by-products. The astaxanthin encapsulation efficiency on day 0 and astaxanthin recovery on day 1 were recorded at 66.6 ± 2.7% and 94.4 ± 4.6%, respectively.

CONCLUSIONS

The utilization of OO as an extraction solvent for astaxanthin from shrimp by-products in UAE represents a novel and promising approach to reducing the environmental impact of shrimp by-products. The effective astaxanthin encapsulation efficiency highlights its potential application in food industries.

Enhancing the Stability and Bioaccessibility of Tree Peony Seed Oil Using Layer-by-Layer Self-Assembling Bilayer Emulsions

Tree peony seed oil (TPSO) is an important plant source of n-3 polyunsaturated fatty acid (α-linolenic acid, ALA > 40%) that is receiving increasing attention for its excellent antioxidant and other activities. However, it has poor stability and bioavailability. In this study, a bilayer emulsion of TPSO was successfully prepared using a layer-by-layer self-assembly technique. Among the proteins and polysaccharides examined, whey protein isolate (WPI) and sodium alginate (SA) were found to be the most suitable wall materials. The prepared bilayer emulsion contained 5% TPSO, 0.45% whey protein isolate (WPI) and 0.5% sodium alginate (SA) under selected conditions and its zeta potential, droplet size, and polydispersity index were -31 mV, 1291 nm, and 27%, respectively. The loading capacity and encapsulation efficiency for TPSO were up to 84% and 90.2%, respectively. It was noteworthy that the bilayer emulsion showed significantly enhanced oxidative stability (peroxide value, thiobarbituric acid reactive substances content) compared to the monolayer emulsion, which was accompanied by a more ordered spatial structure caused by the electrostatic interaction of the WPI with the SA. This bilayer emulsion also exhibited markedly improved environmental stability (pH, metal ion), rheological properties, and physical stability during storage. Furthermore, the bilayer emulsion was more easily digested and absorbed, and had higher fatty acid release rate and ALA bioaccessibility than TPSO alone and the physical mixtures. These results suggest that bilayer emulsion containing WPI and SA is an effective TPSO encapsulation system and has significant potential for future functional food development.

Targeted delivery of food functional ingredients in precise nutrition: design strategy and application of nutritional intervention

With the high incidence of chronic diseases, precise nutrition is a safe and efficient nutritional intervention method to improve human health. Food functional ingredients are an important material base for precision nutrition, which have been researched for their application in preventing diseases and improving health. However, their poor solubility, stability, and bad absorption largely limit their effect on nutritional intervention. The establishment of a stable targeted delivery system is helpful to enhance their bioavailability, realize the controlled release of functional ingredients at the targeted action sites in vivo, and provide nutritional intervention approaches and methods for precise nutrition. In this review, we summarized recent studies about the types of targeted delivery systems for the delivery of functional ingredients and their digestion fate in the gastrointestinal tract, including emulsion-based delivery systems and polymer-based delivery systems. The building materials, structure, size and charge of the particles in these delivery systems were manipulated to fabricate targeted carriers. Finally, the targeted delivery systems for food functional ingredients have gained some achievements in nutritional intervention for inflammatory bowel disease (IBD), liver disease, obesity, and cancer. These findings will help in designing fine targeted delivery systems, and achieving precise nutritional intervention for food functional ingredients on human health.

Construction of benzyl isothiocyanate-loaded fish skin gelatin-luteolin compound emulsion delivery system, and its digestion and absorption characteristics

BACKGROUND

Fish skin gelatin (FSG) and luteolin (LUT) were used as composite emulsifiers, and benzyl isothiocyanate (BITC) was used as a model of nutrient delivery to construct a stable emulsion. The storage stability of the FSG-LUT emulsion and its effect on BITC release were investigated both in vitro and ex vivo.

RESULTS

LUT can quench FSG fluorophores statically and form a stable complex through hydrogen bonding and hydrophobic interactions. The FSG-LUT emulsion storage stability and embedding rate were higher than those of the FSG emulsion. The FSG-LUT emulsion microstructure was resistant to oral and gastric digestion, and the BITC retention rate and bioaccessibility were much higher than those of the FSG emulsion. Lastly, the ex vivo everted gut sac of rat intestine study demonstrated that BITC showed the highest absorption in the ileum, and the FSG-LUT emulsion absorbed BITC and sustained a controlled release in a specific position.

CONCLUSION

LUT could form stable complexes with FSG, which improved the stability and bioavailability of BITC in the FSG-LUT emulsion delivery system, and promoted further intestinal BITC absorption. © 2022 Society of Chemical Industry.

Digestion behavior, in vitro and in vivo bioavailability of cannabidiol in emulsions stabilized by whey protein-maltodextrin conjugate: Impact of carrier oil

An emulsion delivery system may be affected significantly by oil phase composition in terms of digestion behavior and bioavailability of the delivered substance. In this study, emulsions loaded with cannabidiol (CBD) were prepared with medium chain triglyceride (MCT), long chain triglyceride (LCT) or MCT/LCT(1:1) as carrier oil and whey protein-maltodextrin conjugate as emulsifier, and the digestion behavior of emulsion and bioavailability of CBD were assessed in vitro and in vivo. The particle size of emulsions throughout the in vitro digestion process was in the order of MCT < MCT/LCT < LCT, and three emulsions showed consistent particle size changes: stable in oral phase, sharply increased in gastric phase, and decreased in small intestine. After intestinal digestion, about 90% of free fatty acids (FFA) was released in MCT emulsion, followed by MCT/LCT (76%) and then LCT (45%). CBD was degraded during gastrointestinal digestion and the transformation stability of CBD in oil phase was in the order of LCT > MCT/LCT > MCT. Although CBD had higher bioaccessibility in MCT and MCT/LCT emulsions, the bioavailability of CBD in LCT was the highest (43%), followed by MCT/LCT (39%), MCT (33%). In vivo pharmacokinetic study showed that MCT/LCT and LCT were more favorable for CBD transport and absorption. The results may provide useful information for the construction of delivery systems, protecting CBD molecules, and improving their bioavailability.

Enhanced encapsulation efficiency and controlled release of co-encapsulated Bacillus coagulans spores and vitamin B9 in gellan/κ-carrageenan/chitosan tri-composite hydrogel

The current study, for the first time, attempts to co-encapsulate Bacillus coagulans spores as probiotics and vitamin B9 in the polysaccharide-based matrix for their targeted delivery. Instead of vegetative cells, probiotic spores were chosen owing to their higher stability. The matrix, tri-composite hydrogel, was synthesized from gellan, κ-carrageenan, and chitosan through self-assembly devoid of chemical cross-linkers. Hence, it was found suitable for application in the co-encapsulation of bioactive compounds. The synthesized hydrogel showed remarkable encapsulation efficiency for folic acid and probiotic spores, both individually and in combination. At acidic pH, loaded hydrogel exhibited 28.42 % and 45.14 % release of spores and folic acid, respectively, which was comparatively lower than the trends observed under neutral and alkaline pH. These results were correlated with the release pattern observed during in vitro digestibility studies. Moreover, spore conversion to vegetative cells and its high colonization were observed in the simulated intestinal phase. Therefore, the matrix maintained viability and stability of co-encapsulated folic acid and bacterial spores in gastric pH while they were slowly released in the intestinal phase. These promising findings pave the way to develop a natural matrix for co-encapsulating various bioactive compounds and probiotics.

Preparation and characterization of astaxanthin-loaded microcapsules and its application in effervescent tablets

BACKGROUND

Astaxanthin is a type of keto-carotene with potential health benefits. However, astaxanthin has poor solubility and stability, resulting in its low oral bio-availability. Microcapsules can be used to improve the water solubility, stability and oral bio-availability of lipophilic bioactive compounds. Effervescent tablets can further improve the stability, smell and taste of microcapsules, and are more easily accepted by consumers.

RESULTS

Astaxanthin-loaded microcapsules were prepared by layer-by-layer assembly and freeze-drying technologies. Sodium caseinate and κ-carrageenan were applied as wall materials. The prepared microcapsules had good flow properties and encapsulation efficiencies (> 85%). Fourier transform infrared spectroscopy demonstrated that the mechanisms of layer-by-layer self-assembly between sodium caseinate and κ-carrageenan might be electrostatic adsorption and hydrogen bonding. The preparation process and excipients did not affect the antioxidant effect of astaxanthin. The in vitro simulated digestion study showed that microcapsules were mainly dissolved and digested in the simulated intestinal solution. Compared with its raw material, microencapsulation could improve the bio-accessibility of astaxanthin greatly. Then, astaxanthin-loaded microcapsules were incorporated into effervescent tablets by wet granulation and tablet-pressing methods. The dissolution of astaxanthin from effervescent tablets was over 90% in 2 h, which indicated a good dissolution effect. A cytotoxicity study revealed that astaxanthin loaded effervescent tablets had a good biocompatibility. Encapsulating astaxanthin-loaded microcapsules in effervescent tablets can improve its chemical stability.

CONCLUSION

Effervescent tablets containing microcapsules could be used to improve the solubility, stability and bio-accessibility of lipophilic bioactive compounds. © 2022 Society of Chemical Industry.

Improved physicochemical stability and bioaccessibility of astaxanthin-loaded oil-in-water emulsions by a casein-caffeic acid-glucose ternary conjugate

In this study, the influence of casein-caffeic acid-glucose ternary conjugate (CSC) on the physicochemical properties and bioaccessibility of astaxanthin-loaded emulsion was investigated and compared with sodium caseinate (CSN), a synthetic emulsifier commonly used in the food industry. The CSC-stabilized emulsion exhibits droplet characteristics similar to CSN-stabilized emulsion, and can effectively resist the external forces that lead to the phase separation of the emulsion. Although phase separation also occurred at pH 4.0, CSC emulsion had a wider range of pH stability (pH 3.0, 5.0-8.0) and higher salt ion stability than CSN emulsion. Furthermore, CSC-stabilized astaxanthin emulsions showed better astaxanthin protection under different heat treatment conditions and storage temperatures compared with CSN. After 28 days of storage at 4 °C, astaxanthin residues in the CSC-stabilized emulsion reached 92.37 %. The bioaccessibility of astaxanthin in CSC-stabilized emulsion was 26.21 %, much higher than that in CSN (6.47 %). This research study provides a platform for designing astaxanthin-fortified food or beverage systems to achieve better stability and delivery to target sites.

Improved Stabilization and In Vitro Digestibility of Mulberry Anthocyanins by Double Emulsion with Pea Protein Isolate and Xanthan Gum

There is significant evidence that double emulsion has great potential for successfully encapsulating anthocyanins. However, few research studies are currently using a protein-polysaccharide mixture as a stable emulsifier for double emulsion. This study aimed to improve the stability and in vitro digestibility of mulberry anthocyanins (MAs) by employing a double emulsion composed of pea protein isolate (PPI) and xanthan gum (XG). The influence of various XG concentrations (0%, 0.2%, 0.4%, 0.6%, 0.8%, 1.0%) and different temperatures (5 °C, 25 °C, 45 °C, 65 °C) on the physical stability and the thermal degradation of MAs from double emulsions were investigated. In addition, the physicochemical properties of double emulsions and the release performance of MAs during in vitro simulated digestion were evaluated. It was determined that the double emulsion possessed the most stable physical characteristics with the 1% XG addition. The PPI-1% XG double emulsion, when compared to the PPI-only double emulsion, expressed higher thermal stability with a retention rate of 83.19 ± 0.67% and a half-life of 78.07 ± 4.72 days. Furthermore, the results of in vitro simulated digestion demonstrated that the MAs in the PPI-1% XG double emulsion were well-protected at oral and gastric with ample release found in the intestine, which was dissimilar to findings for the PPI-only double emulsion. Ultimately, it was concluded that the double emulsion constructed by the protein-polysaccharide system is a quality alternative for improving stability and absorption with applicability to a variety of food and beverage systems.

Preparation of Oxidized Starch/β-Lactoglobulin Complex Particles Using Microfluidic Chip for the Stabilization of Astaxanthin Emulsion

Here, we designed an oxidized starch/β-lactoglobulin (OS/β-lg) complex colloidal particle using a dual-channel microfluidic chip for the stabilization of astaxanthin emulsion. The effect of the mixing ratio, pH, and the degree of substitution (DS) of the oxidized starch on the formation of OS/β-lg complex particles was investigated in detail. The optimal complexation occurred at a pH of 3.6, a mixing ratio of 2:10, and a DS of 0.72%, giving an ideal colloidal particle with near-neutral wettability. With this optimum agent, the astaxanthin-loaded oil-in-water emulsions were successfully prepared. The obtained emulsions showed the typical non-Newton fluid behavior, and the rheological data met the Herschel-Bulkley model. The microscopic images confirmed the dense adsorption of the particle on the oil/water interface. In vitro release and stability studies demonstrated this compact layer contributed to the controlled-release and excellent stability of astaxanthin emulsions facing heat, ultraviolet, and oxidative intervention. This work suggests the potential of microfluidics for the production of food-grade solid emulsifiers.

Influence of fish skin gelatin-sodium alginate complex stabilized emulsion on benzyl isothiocyanate stability and digestibility in vitro and in vivo

BACKGROUND

An emulsion delivery system for benzyl isothiocyanate (BITC) was prepared using fish skin gelatin (FSG) and sodium alginate (Alg). The effects of the FSG-Alg complex on the emulsion stability and BITC release pattern from the emulsion were investigated in vitro and in vivo.

RESULTS

The storage stability and embedding rate of the 10 g kg^-1 FSG and 2.5 g kg^-1 Alg (FSG-Alg) emulsion were the highest among all samples. The FSG-Alg complex provided BITC a better protection during in vitro digestion. The microstructure of the FSG-Alg emulsions was more stable during in vitro digestion, and the bioaccessibility and retention rate of BITC were much higher compared to those of the FSG emulsion. The results of the ex vivo everted gut sac of rat intestine study showed that the FSG-Alg emulsion significantly increased the BITC absorption rate in the duodenum.

CONCLUSION

The FSG-Alg emulsion delivery system is a highly stable system for the delivery of BITC that improves the bioaccessibility of BITC and promotes its absorption in the duodenum. © 2022 Society of Chemical Industry.

Enhancing the Formation and Stability of Oil-In-Water Emulsions Prepared by Microchannels Using Mixed Protein Emulsifiers

Although natural emulsifiers often have many drawbacks when used alone, their emulsifying ability and stability can usually be improved unexpectedly when used in combination. In this study, monodisperse emulsions stabilized by combining two natural protein emulsifiers, i.e., whey protein isolate (WPI) and sodium caseinate (SC), in different proportions were prepared using microchannel (MC) emulsification. The influences of temperature, pH, ionic strength, and storage time on the microstructure and stability of the emulsions were examined. Analysis of the microstructure and droplet size distribution revealed that the WPI-, SC-, and mixed protein-stabilized emulsions exhibited uniform droplet distribution. The droplet size and ξ-potential of the MC emulsions stabilized by mixed protein emulsifiers were higher than those of the emulsions stabilized by WPI or SC separately. The emulsions stabilized by the two types of proteins and mixed emulsifiers had better stability under high salt concentrations than the synthetic emulsifier Tween 20. WPI-SC-stabilized emulsions were more resistant to high temperatures (70–90°C) and exhibited excellent stabilization than those stabilized by WPI and SC, which was attributed to the more sufficient coverage provided by the two types of protein emulsifier layers and better protein adsorption at the oil-water interface. These results indicate that WPI-SC is a potential stabilizer for MC emulsion requirements. This study provides a basis for the formulation of monodisperse and stable natural emulsion systems.

Characterization of Capsicum oleoresin microparticles and in vivo evaluation of short-term capsaicin intake

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Modified malt was successfully used in Capsicum oleoresin microencapsulation.

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High antioxidant activities by ORAC and FRAP were observed for all microparticles.

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Diet containing Capsicum oleoresin microparticles can promote weight gain control.

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Liver damage caused by obesity was prevented by high doses of Capsicum's oleoresin.

Gum arabic, modified corn starch (EMCAP), modified malt (MALT), either blended or isolated, were assessed as encapsulating agents for Capsicum oleoresin. Capsicum oleoresin microparticles were obtained by spray drying and analysed for physicochemical properties and in vivo. Obtained powders were adequate for storage, given their low water activity (<0.150), hygroscopicity (<11.43 g/100 g), moisture (<4.76%) and high glass transition temperature (<98.3 °C). FT-IR analysis concluded that carbohydrates matrices were loaded after spray drying, with peaks around 2850 cm ^–1 for aromatic compounds, and bands around 1760 cm⁻¹, pointing to the presence of capsaicin inside the microparticles. All formulations exhibited high antioxidant activity, low contact angles and great solubility in water. Any adverse effect was observed in the experimental assay, neither change on the level of hepatic aminotransferases. The intake of a High-Fat Diet (HFD) supplemented with Capsicum oleoresin microparticles decreased weight gain when compared to the HFD control.

Preparation and Evaluation of Undaria pinnatifida Nanocellulose in Fabricating Pickering Emulsions for Protection of Astaxanthin

Pickering emulsions stabilized from natural sources are often used to load unstable bio-active ingredients, such as astaxanthin (AXT), to improve their functionality. In this study, AXT-loaded Pickering emulsions were successfully prepared by 2,2,6,6-tetramethy-1-piperidine oxide (TEMPO)-oxidized cellulose nanofibers (TOCNFs) from Undaria pinnatifida. The morphology analysis showed that TOCNFs had a high aspect ratio and dispersibility, which could effectively prevent the aggregation of oil droplets. The stable emulsion was obtained after exploring the influence of different factors (ultrasonic intensity, TOCNFs concentration, pH, and ionic strength). As expected, AXT-loaded Pickering emulsions showed good stability at 50 °C and 14 days of storage. The results of simulated in vitro digestion showed that the emulsions exhibited higher release of free fatty acids (FFAs) and bioaccessibility of AXT than those in sunflower oil. Hence, our work brought new insights into the preparation of Pickering emulsions and their applications in protection and sustained, controlled release of AXT.

High internal phase emulsions stabilized by native and heat-treated lactoferrin-carboxymethyl chitosan complexes: Comparison of molecular and granular emulsifiers

While the high internal phase emulsions (HIPEs) have been formed by food-grade biopolymers and granules have been widely reported, it is not known which components are more effective. In this work, we first used heat-treated lactoferrin (LF)-carboxymethyl chitosan (CMCTS) granules and native LF-CMCTS physical mixtures as emulsifiers to form HIPEs. The results showed that the interfacial behavior and emulsifying properties of the two complexes were controlled by the ratio of LF-CMCTS and the optimal ratio of LF to CMCTS was 1:1. Heated LF-CMCTS granules anchored to the water-oil interface and formed an elastic shell to stabilize HIPEs, while unheated LF-CMCTS complexes formed a thick film layer to stabilize HIPEs. Both HIPEs could act as delivery systems loaded with curcumin, and they showed better protection of curcumin than Tween-80 under light. This study provides a new basis for the design of LF-based HIPEs systems loaded with lipophilic food functional ingredients.

Recent progress in oil-in-water-in-oil (O/W/O) double emulsions

Oil-in-water-in-oil (O/W/O) double emulsions are recognized as an advanced design route for oil structuring that shows promising applications in the pharmaceutical, cosmetic, and food fields. This review summarizes the main research advances of O/W/O double emulsions over the past two decades. It mainly focuses on understanding the preparation strategies, stabilization mechanism, and potential applications of O/W/O double emulsions. Several emulsification strategies are discussed, including traditional two-step emulsification method, phase-inversion approach, membrane emulsification, and microfluidic emulsification. Further, the role of interfacial stabilizers and viscosity in the stability of O/W/O double emulsions will be discussed with a focus on synthetic emulsifiers, natural biopolymer sand solid particles for achieving this purpose. Additionally, analytical methods for evaluating the stability of O/W/O double emulsions, such as advanced microscopy, rheology, and labeling assay are reviewed taking into account potential limitations of these characterization techniques. Moreover, possible innovative food applications are highlighted, such as simulating fat substitutes to decrease the trans- or saturated fatty acid content and developing novel delivery and encapsulation systems. This review paves a solid way for the exploration of O/W/O double emulsions toward large-scale implementation within the food industry.

Monoglyceride oleogels for lipophilic bioactive delivery - Influence of self-assembled structures on stability and in vitro bioaccessibility of astaxanthin

The present study investigated the influence of self-assembled structures on stability and in vitro bioaccessibility of astaxanthin by modifying the structures with different processing conditions. The self-assembled structures of GMS oleogels were changed to produce smaller crystals and more compact network at higher glycerol monostearate (GMS) concentration and lower cooling temperature, resulting in higher hardness, oil binding capacity, and viscoelastic properties of oleogels. In the stability test, the highest retention ratio of astaxanthin was observed in oleogels formed at 4 °C and 10% GMS, indicating that the denser network structures were more effective to prevent the degradation of astaxanthin. During in vitro digestion, the self-assembled structures of oleogels and the nature of GMS molecules affected the lipolysis and micellization, which in turn regulated the bioaccessibility of astaxanthin. Collectively, GMS oleogels were effective delivery materials for improving the stability and bioaccessibility of lipophilic bioactives.

Novel freeze-drying matrix for enhancing viability of probiotic supplemented milkshake during simulated in vitro digestion

Probiotics are recognized as essential components to improve health and regulate immune functions. Despite several probiotic formulations, the anticipation for non-fermented probiotic foods is noticeable. The objective of the study was to investigate and develop a stable freeze-dried synbiotic formula that can serve the purpose of a probiotic enricher as well as a thickener in an instant milk-based beverage. The freeze-dried synbiotic formula was assessed for the protective effect of whey protein-polysaccharides for retaining high cell viability during freeze-drying and subsequent storage. Highest survival rates were obtained for WP-15%I (85.90%), WP-15%P (85.43%), and WP-0.6%X (80.23%) combinations. During storage at 4 °C for 75 d, a lower specific rate of cell inactivation was found for WP-0.4%X (-0.0184 day^-1), WP-5%P (-0.0197 day^-1) and WP-5%I (-0.023 day^-1). Subsequent ingestion of synbiotic portions in the gastro-intestinal digestion simulator was studied in two ways to enumerate the retaining cell viability and understanding the importance of co-ingested food. Synbiotic portions reconstituted in milk showed higher probiotic survival through gastrointestinal digestion than water demonstrating the significance of supporting food matrix for improving the survival and efficiency of probiotics.