Bioaccessibility Of Β-carotene Research Articles

Chitosan hydrochloride/carboxymethyl starch complex nanogels stabilized Pickering emulsions for oral delivery of β-carotene: Protection effect and in vitro digestion study

β-Carotene was encapsulated in the Pickering emulsions stabilized by chitosan hydrochloride – carboxymethyl starch (CHC-CMS) nanogels. During ultraviolet radiation and storage, the retention of β-carotene in Pickering emulsions was higher than that of other formulations, such as Tween 80 stabilized emulsions (TEs) and bulk oil. The Pickering emulsions were found to be stable during thermal treatment. Meanwhile, lipid oxidation was delayed in Pickering emulsions compared to TEs and bulk oil. The vitro digestion results suggested that the free fatty acids (FFA) released were below 30% for all Pickering emulsions, which indicated that a physical barrier was formed by CHC-CMS nanogels to restrain the lipid hydrolysis. The bioaccessibility of β-carotene in Pickering emulsions was higher than that in bulk oil. This research helped establish a connection between the physicochemical properties of CHC-CMS stabilized Pickering emulsions with their applications in the protection effect and oral delivery of bioactive compounds.

Fabrication of high internal phase Pickering emulsions with calcium-crosslinked whey protein nanoparticles for β-carotene stabilization and delivery.

Whey protein isolate (WPI) nanoparticles were fabricated with Ca2+ induced cross-linking and used as an effective particle stabilizer for high internal phase Pickering emulsion (HIPPE) formulation aiming to improve the chemical stability and bioaccessibility of β-carotene (BC). Ca2+ concentration dominated the characteristics of WPI nanoparticles. Spherically shaped and homogeneously dispersed WPI nanoparticles with a Z-average diameter of approximately 150.0 nm were obtained with 5.0 mM Ca2+ concentration. No cytotoxicity was observed for WPI nanoparticles even at 10.0 mg mL-1 concentration. HIPPE (oil fraction 80.0%, w/w) can be successfully prepared with WPI nanoparticles at a concentration as low as 0.2% (w/w) and was stable for at least 2 months at room temperature. A higher WPI nanoparticle concentration resulted in more solid-like HIPPEs. BC exhibited appreciably higher retention in HIPPEs than in bulk oil during 30 days of storage at 50 °C. Moreover, BC bioaccessibility was appreciably improved with the HIPPE delivery system. Both the chemical stability and bioaccessibility of BC increased with the increase of WPI nanoparticle concentrations from 0.2 to 1.0% (w/w). The results obtained in this study may facilitate the fabrication of edible and biocompatible protein-based nanoparticle stabilizers for HIPPE formulation with more innovative and tailored functionalities.

Construction of octenyl succinic anhydride modified porous starch for improving bioaccessibility of β-carotene in emulsions.

Modified porous starch (PS), by introducing octenyl succinic anhydride (OSA) moieties, was synthesized successfully, which was applied as an emulsion of β-carotene for the first time. The pores and channels within porous starch provided more possibilities for OSA to modify starch. The ester linkage of OSA modified PS with different degrees of substitution (DS) were confirmed by both 13C solid-state NMR and Fourier transform-infrared spectroscopy (FT-IR). The hydrophobic octenyl succinic and hydrophilic hydroxyl groups of OSA modified PS showed the good emulsifying capability, which could be utilized to prepare β-carotene emulsions. And the bioaccessibility of β-carotene was also enhanced with increasing DS of OSA modified starch. This study not only paves a new way using porous starches for modification of starch, but also offers an attractive alternative for obtaining emulsion-based delivery systems for bioactive components.

Factors impacting lipid digestion and β-carotene bioaccessibility assessed by standardized gastrointestinal model (INFOGEST): oil droplet concentration.

Food, nutrition, and pharmaceutical scientists are trying to elucidate the major factors impacting the bioavailability of macronutrients (e.g., lipids) and micronutrients (e.g., vitamins) so as to improve their efficacy. Currently, there is still a limited understanding of how food matrix effects impact digestion and bioaccessibility determined under the INFOGEST model, which is currently the most widely used standardized in vitro gastrointestinal model. Therefore, we examined the impact of corn oil concentration on lipid digestion and β-carotene bioaccessibility using model food emulsions. For all oil concentrations tested (2.5 to 20%), complete lipid digestion was achieved using fed-state gastrointestinal conditions, which could only be seen if a back-titration was performed. The particle size and negative surface potential on the mixed micelles formed at the end of the small intestine phase both increased with increasing oil concentration, which was attributed to the generation of more free fatty acids. The β-carotene bioaccessibility increased when the oil concentration was raised from 2.5 to 10% due to the increased solubilization capacity of the mixed micelles, but then it decreased when the oil concentration was raised further to 20% due to precipitation and sedimentation of some of the β-carotene. The maximum β-carotene bioaccessibility (93.2%) was measured at 10% oil. These results indicate that the oil concentration of emulsions influences β-carotene bioaccessibility by altering digestion, solubilization, and precipitation processes. This knowledge is important when designing more effective functional or medical food products.

The lipid type affects the in vitro digestibility and β-carotene bioaccessibility of liquid or solid lipid nanoparticles

Solid lipid nanoparticles (SLNs) are emulsion-based carriers of lipophilic bioactive compounds. However, their digestibility may be affected by the solid lipid phase composition. Hence, the aim of this work was to study the in vitro lipolysis kinetics as well as the relationship between the lipid digestion, micelle fraction composition and β-carotene bioaccessibility of SLNs with different solid lipids, being blends of medium chain triglyceride (MCT) oil, glyceryl stearate (GS) or hydrogenated palm oil (HPO) as compared to liquid lipid nanoparticles (LLNs) with pure MCT. SLNs formulated with GS were fully digested, similarly to LLNs. However, HPO-containing SLNs presented slower lipolysis kinetics during the intestinal phase at increasing HPO concentration. Despite this, HPO-SLNs showed higher β-carotene bioaccessibility, which was related to the higher amount of monounstaturated free fatty acids in the micelle fraction. Thus, this work provides valuable insight for designing delivery systems of bioactive compounds with optimal functionality.

Modulation of physicochemical stability and bioaccessibility of β-carotene using alginate beads and emulsion stabilized by scallop (Patinopecten yessoensis) gonad protein isolates.

The colloidal delivery systems fabricated by emulsion containing natural proteins and lipids have been utilized to protect carotenoids as well as to release the carotenoids in the simulated in vitro gastrointestinal tract (GIT). In this study, β-carotene (BC) was embedded into emulsions that were stabilized by scallop gonad protein isolates (SGPIs), and the emulsion droplets containing BC were then entrapped into calcium-alginate beads. The results showed that the oil-in-water emulsions coated by SGPIs only showed good stability at pH 7-8, while the emulsion-alginate beads remained relatively intact at pH 3-8. BC encapsulated in emulsions was extremely unstable and prone to degradation when stored at the comparatively higher temperature (37°C), whereas the stability of BC was greatly enhanced through incorporation into emulsion-alginate beads. The digestion rate and extent of lipid droplets constructed within SGPIs-stabilized emulsion-alginate beads were slower than that in emulsions during GIT. The confocal laser scanning microscopy revealed that the lipid droplets in emulsions were aggregated after exposure to the mouth and gastric phases, while the emulsion-alginate beads maintained their spherical shape after exposure to the oral and gastric phases. Moreover, the free lipid droplets in the emulsions showed a higher bioaccessibility of BC (66%) than that in the emulsion-alginate beads (38%), whereas the BC transformation was on the contrary. The findings in this study indicated that SGPIs-stabilized emulsion in alginate beads can potentially be utilized for the encapsulation and controlled release of lipophilic bioactive compounds.

Anti-Inflammatory Effect of Crude Momordica charantia L. Extract on 2,4,6-Trinitrobenzene Sulfonic Acid-Induced Colitis Model in Rat and the Bioaccessibility of its Carotenoid Content.

Momordica charantia L., known as bitter melon (BM), is a plant that belongs to the family Cucurbitaceae. Aims of this study are to investigate the anti-inflammatory effect of crude BM extract on 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced experimental colitis model in rat. It was also aimed to determine the content and bioaccessibility of carotenoids of BM. BM was purchased from local markets in Izmir, Turkey. Fruits of BM were lyophilized, powdered, and used in the experiment. Carotenoids were determined by high-performance liquid chromatography. To determine the bioaccessibility of β-carotene, in vitro digestion was performed. Wistar albino rats were divided into four groups: group A (BM+TNBS), group B (BM), group C (TNBS), and group D (control). BM solution was given 300 mg/(kg·day) for 6 weeks orally. Colitis was induced by 0.25 mL of a solution containing 100 mg/kg 5% (w/v) TNBS in 50% ethanol (w/v) intrarectally after 6 weeks. After sacrification, macroscopic and microscopic evaluations were performed. Myeloperoxidase, cytokines levels (interleukin-17 [IL-17], TNF-alpha, and interleukin-10 [IL-10]) were measured in serum and colonic samples by ELISA test. Institutional Animal Ethics Committee approval was obtained. Total carotenoid content of BM was determined 11.7 mg/g dry weight as β-carotene equivalents. Bioaccessibility of total carotenoids was determined as 2.1% with in vitro digestion. Pretreatment with crude BM extract significantly reduced weight loss, macroscopic, and microscopic colitis damages in colonic samples (P = .000), (P = .015), and (P = .026), respectively. Serum anti-inflammatory cytokine IL-10 increased significantly in both treatment groups (P = .000). BM is a rich source of carotenoids, but the bioaccessibility of its carotenoids is low. This study displays that BM has protective anti-inflammatory effects on TNBS-induced colitis.

Development, physical stability and bioaccessibility of β-carotene-enriched tertiary emulsions

Abstract The aim of this study was to develop a β-carotene-enriched tertiary emulsion (lactoferrin/alginate/e-poly- l -lysine). Then, its physical stability as well as β-carotene content under external stresses (temperature, pH and ionic strength changes) was evaluated. Furthermore, lipid digestibility and β-carotene bioaccessibility of primary, secondary and tertiary emulsions were determined. Tertiary emulsion underwent a substantial particle size increase up to 13 μm after extreme temperatures, acidic conditions and with salt addition. However, small particle size (0.41 μm) and negative ζ-potential (−43.4 mV) was observed at basic pH. In addition, β-carotene content in tertiary emulsions decreased only 40% when emulsions were subjected at temperatures ≤70 °C, in acidic conditions and below 0.3 M NaCl. After in vitro digestion, tertiary emulsion presented higher lipid digestibility (83.59 ± 11.81%) and β-carotene bioaccessibility (70.10 ± 5.26%) compared with primary and secondary emulsions. This study provides knowledge to understand the behaviour of β-carotene-loaded tertiary emulsions under different conditions, valuable for further application in foodstuffs.

Thermal disruption of the food matrix of biofortified lettuce varieties modifies absorption of carotenoids by Caco-2 cells

Amongst green leafy vegetables, new varieties of lettuce enriched in lutein and β-carotene are being developed to provide increased supply of dietary carotenoids. We investigated the effect of lettuce genotypes (varieties) and thermal treatments on lutein and β-carotene bioaccessibility to the micellar fraction (and also carotenoid bioavailability) using a human Caco-2 cell model system. Carotenoid absorption by mammalian cells is not correlated with initial carotenoid concentration in fresh lettuce leaves. While thermal treatment of lettuce leaves increases carotenoid availability, resulting in higher lutein and β-carotene absorption, disruption of the food matrix by prior cooking results in reduced carotenoid levels and transfer to the micellar fraction. Unless the food matrix is disrupted through breeding or post-harvest treatments, absorption of carotenoids from biofortified lettuce remains similar to lettuce cultivars with low carotenoid levels. Genetic improvement programs for biofortified lettuce varieties need to focus on increasing the carotenoid bioavailability from the food matrix.

Enzymatic degradation and bioaccessibility of protein encapsulated β-carotene nano-emulsions during in vitro gastro-intestinal digestion

The aim of this research was to investigate the impact of proteolysis, lipolysis and bile salts on the stability of oil in water emulsions stabilized by proteins and their effect on bioaccessibility of β-carotene in an O/W emulsion system. Nano-emulsions were prepared with whey protein isolate (WPI), soy protein isolate (SPI) and sodium casein (SC) with a microfluidizer under the same operating conditions. The emulsions were characterized by particle size, confocal microscopy, interfacial composition, zeta-potential and digestive properties as a function of time during simulated gastro-intestinal incubation. The WPI-based emulsion was relatively stable in simulated gastric fluid due to the emulsifying activity of β-lactoglobulin, a major component of WPI, while SPI and SC was inclined to aggregate in the presence of pepsin. However, rapid adsorption of lipolysis products and bile salts at the oil-water interfaces for WPI and SC samples sterically hindered the approach of lipase to the lipid core, leading to decreased lipolysis and micellization rates. In the case of SPI-based emulsions, bile salts adsorption and displacement occurred at a lower rate but a higher extent, which provided more surface binding sites for enzymes and accelerated lipolysis. These studies provide information about the relationship between the effects of digestion of the interfacial proteins and the bioaccessibility of lipophilic emulsion contents that could guide the design of safe protein based emulsified bioactive molecular delivery systems.

Contenido de nutrientes en vegetales y frutas y bioaccesibilidad in vitro durante el almacenamiento pos-cosecha

Vegetables and fruits are sources of high-quality nutrients and bioactive compounds for healthy life, but during the storage time, physiological changes modify the content or availability of these. In addition to local conditions of production, post-harvest handling and consumption habits, there are many factors that also change the amount and bioaccessibility of nutrients. In consequence, the objectives of this study were to determine some nutrient contents (β-carotene, glucose), theirs in vitro bioaccessibility and others phytochemicals compounds (Vitamin C, dietary fiber, total polyphenols) in winter squashes (Cucurbita spp.), sweet potatoes (Ipomoea batatas) and native fruits such as butia (Butia odorata) in the edible portion and during local storage condition. All data were determined for 100 g fresh weight. The β-carotene contents were higher in orange pulps for sweet potato (70 mg), winter squash (21 mg) and low in butia (0.65 mg). Instead, the in vitro bioaccessibility of β-carotene was between 0.5 to 7%. The total glucose content was higher in sweet potato (10.3 to 18.6 g) than winter squash (1.4 to 3.8 g) and their in vitro bioaccessibility was 0.1 to 7.3%. All vegetables and fruits were sources of Vitamin C (19.6 to 59.5 mg AAE); dietary fiber (2.5 to 3.8 g) and total polyphenols (20.5 to 265.8 mg AGE). The amounts of the compounds were dependent in each species of the interaction between the variety and the storage time. These results demonstrate that the varieties and the time of storage significantly affect the nutritional values in vegetables and fruits analyzed, and provide information to define more adequate diets to local resources.

Whey protein isolate modulates beta-carotene bioaccessibility depending on gastro-intestinal digestion conditions

Carotenoids are lipophilic phytochemicals; their intake has been associated with reduced chronic diseases. However, their absorption depends on emulsification during digestion and incorporation into mixed micelles, requiring digestive enzymes, gastric peristalsis, bile, and dietary lipids. In this study, we investigated whether whey-protein-isolate (WPI), a commonly consumed protein source, can modulate β-carotene bioaccessibility in vitro, especially under incomplete digestive conditions, i.e. under low digestive enzyme concentrations. Thus, amounts of pepsin, pancreatin, bile, co-digested lipids and kinetic energy and gastric digestion time were modified, and WPI at concentrations equivalent to 0/25/50% of the protein recommended dietary allowance (approx. 60 g/d) were added to β-carotene dissolved in oil. WPI enhanced bioaccessibility by up to 20% (p < 0.001), especially under higher simulated peristalsis or reduced amount of dietary lipids. Conversely, they impaired bioaccessibility to one third (p < 0.001) under incomplete digestive conditions. WPI modulated β-carotene bioaccessibility depending on digestive conditions.

Impact of emulsifier nature and concentration on the stability of β-carotene enriched nanoemulsions during in vitro digestion.

The presence of emulsifiers facilitates the formation of nanoemulsions and assists in their stabilisation. Moreover, behaviour of nanoemulsions along the gastrointestinal tract primarily depends on their composition, affecting the bioaccessibility of the encapsulated compound. The goal of this work was to study how β-carotene-enriched nanoemulsions prepared with different emulsifiers (Tween 20, lecithin, sodium caseinate, sucrose palmitate) at various concentrations (2%-8%) would affect their stability (particle size and zeta potential) during an in vitro gastrointestinal tract (GIT) digestion. In addition, the lipid digestibility and β-carotene's bioaccessibility of nanoemulsions was determined. Nanoemulsions stabilised with Tween 20, lecithin and sodium caseinate did not present any variation in particle size under stomach phase. After the intestinal GIT phase, all nanoemulsions experienced physical changes, i.e. either increase or decrease in their particle size depending on the nature and concentration of the emulsifier used. The zeta potential of all nanoemulsions was maintained negative throughout the GIT digestion; moreover, it was less negative after the stomach GIT phase (between -24.2 and -1.4 mV). Lecithin-stabilised nanoemulsions presented the highest number of free fatty acids when the emulsifier concentration increased from 2% to 8%. In this sense, nanoemulsions containing 8% of lecithin exhibited the highest β-carotene bioaccessibility (23.5%), suggesting that lecithin can enhance lipid digestion and bioaccessibility of β-carotene encapsulated within nanoemulsions. This study elucidates the importance of not only the emulsifier's nature but also the concentration used when designing nanoemulsions as delivery systems for lipophilic compounds.

Bioaccessibility and cellular uptake of β-carotene in emulsion-based delivery systems using scallop (Patinopecten yessoensis) gonad protein isolates: effects of carrier oil

Emulsion-based delivery systems were structured by using scallop gonad protein isolates (SGPIs) as novel food-grade emulsifiers. The effects of carrier oil, including the long chain triglycerides (LCT) and medium chain triglycerides (MCT), on the bioaccessibility and cellular uptake of β-carotene (BC) were investigated. Both LCT and MCT delivery systems remained stable at pH 7-8 but aggregated at lower pH values (3-6) according to the results of light scattering and microscopy measurements. LCT droplets fabricated within SGPIs were digested and released more slowly than MCT droplets during the simulated gastrointestinal tract digestion. The LCT emulsion showed higher BC bioaccessibility (65.5%) than the MCT emulsion (23.1%) as a result of the greater solubilization of BC in mixed micelles fabricated from long-chain fatty acids. Moreover, the LCT emulsion produced higher cellular uptake of BC as compared with the MCT emulsion in intestinal epithelial cells. These results demonstrated that SGPIs could be used as novel food-grade emulsifiers to protect lipophilic bioactive compounds in emulsion-based delivery systems, in which LCT is more suitable to encapsulate and deliver BC than MCT.

Bioaccessibility and stability of β-carotene encapsulated in plant-based emulsions: impact of emulsifier type and tannic acid.

The effect of two plant-based emulsifiers (quillaja saponin, QS and gum arabic, GA) and a polyphenol (tannic acid) on the formation, stability, digestibility, and β-carotene (BC) bioaccessibility of flaxseed oil-in-water emulsions was investigated. The gastrointestinal behavior of the emulsions was studied using a simulated gastrointestinal tract (GIT) consisting of mouth, stomach, and small intestine regions. In the absence of tannic acid, the initial extent of lipid digestion depended strongly on emulsifier type, with 45% and 76% of the free fatty acids being released after 5 min digestion for QS- and GA-emulsions, respectively. Even so, the lipid droplets were completely digested in both emulsions after 2 h incubation in the small intestine phase. Tannic acid addition (0.01% and 0.1% w/w) slowed down lipid digestion, but did not impact the final extent. The droplets in the QS-emulsions containing 0.1% tannic acid were highly flocculated in the stomach phase. Molecular docking simulations indicated that the interactions between tannic acid and the saponins were mainly driven by hydrogen bonding and hydrophobic interactions. Moreover, they showed that the interactions between tannic acid and QS were stronger at pH 2.5 than at pH 7.0, which would account for the extensive droplet flocculation observed under acidic conditions in the stomach. Emulsifier type and tannic acid addition had no significant influence on BC bioaccessibility. The GA-emulsions exhibited better stability than the QS-emulsions when stored at elevated temperatures (55 °C for 7 days). Tannic acid addition effectively inhibited temperature-induced BC degradation. These results may facilitate the design of more efficacious nutraceutical-loaded functional foods and beverages.

The gastrointestinal behavior of emulsifiers used to formulate excipient emulsions impact the bioavailability of β-carotene from spinach

The impact of the type of emulsifier used to formulate excipient emulsions on the degradation (D*) and bioaccessibility (B*) of β-carotene in spinach was investigated using a simulated gastrointestinal tract (GIT). Emulsions stabilized by sodium caseinate (SC) were more prone to droplet aggregation than those stabilized by either Tween 20 or octenyl succinic anhydride (OSA)-modified starch. The fraction of β-carotene available for absorption (D* × B*) was also affected by emulsifier type: SC (12.0%) > Tween 20 (5.0%) ≈ OSA stabilized (2.6%) (p < 0.05). This effect was mainly attributed to differences in the digestive characteristics of the emulsifiers, which affected the transfer efficiency of β-carotene from the plant tissues to the lipid phase, lipid digestion, and mixed micelle formation. These results show the importance of selecting an appropriate emulsifier when designing excipient emulsions to enhance the bioavailability of nutraceuticals in fruits and vegetables.

Lipid nanoparticles with fats or oils containing β-carotene: Storage stability and in vitro digestibility kinetics.

The aim of this work was to study the formation of lipid nanoparticles (LNPs) with low (corn and olive oil) or high temperature melting lipids (cocoa butter and hydrogenated coconut oil). Moreover, their β-carotene stability and in vitro digestibility kinetics was evaluated. Submicron LNPs (d43 ≈ 570-780 nm) were stabilized with Tween 80 at a surfactant-to-oil ratio (SOR) of 0.1. It was reduced below 200 nm at an SOR of 1. The β-carotene retention at 25 °C was not related to the lipid type but rather to the particle size, being lower in samples with smaller particle sizes. Cocoa butter LNPs presented an equally complete digestion as corn oil LNPs and a high β-carotene bioaccessibility, which was related to the high degree of micellarization of monoacylglycerols. This work evidences the potential of LNPs to protect lipophilic bioactive compounds with a high digestibility and bioaccessibility.

Stability, rheology, and β-carotene bioaccessibility of high internal phase emulsion gels

High internal phase emulsions (HIPEs) were prepared using preheated whey protein isolate (WPI). The influence of cold-set gelation induced by addition of glucono-δ-lactone (GDL) on the microstructure, rheology, water holding capacity (WHC), and stability of HIPEs was determined. In the presence and absence of GDL, the mean particle diameters of HIPEs decreased with increasing WPI concentration. The addition of GDL to the HIPEs did not alter their mean particle diameter or microstructure. The gel strength, hardness, WHC, and stability of HIPEs increased with increasing WPI concentration and with GDL addition. An in vitro digestion experiment showed that β-carotene retention and bioaccessibility was higher after GDL was added to the HIPEs. These findings may be useful for the development of HIPE-based delivery systems for food and other applications.

Impact of Titanium Dioxide on the Bioaccessibility of β-Carotene in Emulsions with Different Particle Sizes

Commercial, titanium dioxide (TiO2) ingredients used as color additives (E171) in foods and beverages contain an appreciable fraction of particles in the nanoscale range. At present, little information is available regarding the potential impact of food-grade TiO2 nanoparticles on the gastrointestinal fate of co-ingested bioactives, such as nutraceuticals. In this study, the impact of TiO2 on the bioaccessibility of β-carotene solubilized in model food emulsions was investigated using a simulated gastrointestinal tract model. Raman spectroscopy showed that there was no charge transfer between β-carotene and TiO2 but that some β-carotene absorbed to the surface of TiO2 particles. The initial particle size of the food emulsion did not significantly affect β-carotene bioaccessibility, probably because the same amount of free fatty acids (FFAs) was released by the end of digestion. The addition of TiO2 at levels typically found in foods also had no significant impact on β-carotene bioaccessibility and FFA release, which suggested that this type of inorganic particle does not interfere with the gastrointestinal fate of these lipophilic bioactive agents. This information is important for ensuring the safety of inorganic nanoparticle utilization within the food industry.

Conformation and emulsifying properties of deamidated wheat gluten-maltodextrin/citrus pectin conjugates and their abilities to stabilize β-carotene emulsions

Maillard conjugation was performed to improve the emulsifying property of deamidated wheat gluten (DWG). The impact on the conformation of DWG and encapsulation of β-carotene was then assessed. DWG was conjugated with maltodextrin (MD) and citrus pectin (CP) via dry-heating at 80 °C and 79% relative humidity. The degree of glycation indicated that the reaction between DWG and MD progressed more rapidly than that between DWG and CP. The electrophoretic protein profile showed that Maillard conjugates possessed larger molecular weight. The Fourier-transform infrared spectroscopy exhibited a new band at 1001 cm−1 for DWG-MD conjugates and at 1631 cm−1 for DWG-CP conjugates, confirming covalent linkage between DWG and the two polysaccharides. Comparison of secondary structure suggested that dry-heating can increase the amount of β-sheet structures and decrease that of α-helix structures, indicating that DWG tended to fold. Fluorescence measurements and atomic force microscope confirmed the folded conformation. Conjugation slowed the folding of DWG. Exposure to different pH and NaCl concentrations indicated that emulsions prepared with DWG-MD conjugates showed better stability than did mixtures under acidic and NaCl conditions. β-Carotene emulsions were then produced from three different DWG-MD conjugates. The emulsions, stabilized by conjugates with MD of larger molecular weight, showed better stability under environmental stress. The in-vitro digestion profile of β-carotene emulsions suggested that β-carotene can be successfully encapsulated within the emulsions stabilized by DWG-MD conjugates with over 59.4% bioaccessibility of β-carotene.