Bioaccessibility Of Β-carotene Research Articles

Emulsion gels prepared from Longzhua mushroom polysaccharides with self-gelling properties as β-carotene carriers: Stability and in vitro digestibility of β-carotene

β-Carotene is widely used in food systems because of its biological activity; however, β-carotene has poor chemical stability and low bioavailability. Thus, researchers use encapsulated delivery systems to overcome these disadvantages. In this study, we prepared emulsion gels to encapsulate β-carotene, using Longzhua mushroom polysaccharide (LMP), which can autonomously form weak gels. The LMP emulsion gel (LEG) exhibited a high water-holding capacity of up to 95.06 %. All samples showed adequate storage stability for 28 days. Increasing the polysaccharide content in the emulsion gel enhanced the encapsulation efficiency of β-carotene (96.76 %–98.27 %), the release of free fatty acids (68.21 %–81.44 %), and the photostability (80.65 %–91.27 %), thermal stability (73.84 %–97.08 %), and bioaccessibility (18.28 %–30.26 %) of β-carotene. In conclusion, LEG is a promising fat-soluble material that can be used for food-grade encapsulated delivery systems.

Enhancing the stability and bio-accessibility of carotenoids extracted from canistel (Lucuma nervosa) via liposomes encapsulation

Canistel (Lucuma nervosa) is a valuable natural source of carotenoids, but their use in the food industry is hampered by low extraction efficiency, poor stability, and limited bio-accessibility. HPLC results showed that a deep eutectic solvent (DES) composed of D-menthol and canoic acid (Men-CaA) has significantly higher extraction yields for lycopene (498.66 ± 3.20 μg/mL DW) and β-carotene (6.43 ± 0.23 μg/mL DW) than corn oil. UV-VIS spectrophotometry combined with response surface methodology results confirmed that the best encapsulation efficiency of liposome for lycopene and β-carotene was attained in the temperature range of 30–70 °C, with the ratio of carotenoid extract to liposome of 1:25 (w/w), the ratio of phospholipids to cholesterol, and the ratio of aqueous phase to lipid phase of 2:1 (v/v). SEM analysis revealed that liposome-encapsulated carotenoid extract formed spherical structures with a uniform texture and rough surface. The ζ-potential assay confirmed the highest stability of liposomes at pH 7. FTIR spectroscopy indicated effective encapsulation of canistel-derived carotenoids by liposomes. Furthermore, liposomes encapsulation improved the thermal and storage stability and bio-accessibility of lycopene and β-carotene. Encapsulating canistel carotenoids in liposomes significantly enhances their stability and bio-accessibility, presenting a viable strategy for preserving the efficacy of food-based active ingredients.

High internal phase Pickering emulsions stabilized by egg yolk-carboxymethyl cellulose as an age-friendly dysphagia food: Tracking the dynamic transition from co-solubility to coacervates

Although protein-polysaccharide complexes with different phase behaviors all show potential for stabilizing high internal phase Pickering emulsions (HIPPEs), it is not clarified which aggregation state is more stable and age-friendly. In this study, we investigated and compared the stability and age friendliness of HIPPEs stabilized with egg yolk and carboxymethyl cellulose (EYCMC) in different phase behaviors. The results revealed differences in particle size, aggregation state, charge potential, and stability of secondary and tertiary structures of EYCMC. The behavior of EYCMC at the oil-water interface was mainly divided into three phases: rapid diffusion, permeation, and reorganization. The electrostatic interaction, kinetic hindrance, and depletion attraction were the mechanisms primarily involved in stabilizing HIPPEs by EYCMC. Rheological analysis results indicated that HIPPEs had excellent viscoelasticity, structural recovery properties and yield stress. HIPPEs were used in 3D printing, electronic nose testing, IDDSI testing and in vitro digestive simulations for the elderly, demonstrating a fine appearance, safe consumption and bioaccessibility of β-carotene. Soluble complexes showed the best stability and age friendliness compared to other aggregated forms. This study serves as a foundational source of information for developing innovative foods utilizing HIPPEs.

Performance of β-carotene-loaded nanostructured lipid carriers under dynamic in vitro digestion system: Influence of the emulsifier type.

A better understanding of how emulsifier type could differently influence the behavior of nanostructured lipid carriers (NLC) under the gastrointestinal digestion process, as well as at the cellular level, is of utmost importance for the NLC-based formulations' optimization and risk assessment in the food field. In this study, NLC composed by fully hydrogenated soybean and high-oleic sunflower oils were prepared using soy lecithin (NLC Lβ) or Tween 80 (NLC Tβ) as an emulsifier. β-Carotene was entrapped within NLC developed as a promising strategy to overcome β-carotene's low bioavailability and stability. The effect of emulsifier type on the digestibility of β-carotene-loaded NLC was evaluated using an in vitro dynamic digestion model mimicking peristalsis motion. The influence of β-carotene-loaded NLC on cell viability was assessed using Caco-2 cells in vitro. NLC Tβ remained stable in the gastric compartment, presenting particle size (PS) similar to the initial NLC (PS: 245.68 and 218.18nm, respectively), while NLC Lβ showed lower stability (PS>1000nm) in stomach and duodenum phases. NLC Tβ also provided high β-carotene protection and delivery capacity (i.e., β-carotene bioaccessibility increased 10-fold). Based on the results of digestion studies, NLC Tβ has shown better physical stability during the passage through the in vitro dynamic gastrointestinal system than NLC Lβ. Moreover, the developed NLC did not compromise cell viability up to 25µg/mL of β-carotene. Thus, the NLC developed proved to be a biocompatible structure and able to incorporate and protect β-carotene for further food applications. PRACTICAL APPLICATION: The findings of this study hold significant implications for industrial applications in terms of developing nanostructured lipid carriers from natural raw materials widely available and used to produce other lipid-based products in the food industry, as an alternative to synthetic ones. In this respect, the β-carotene-loaded NLC developed in this study would find a great industrial application in the food industry, which is in constant search to develop functional foods capable of increasing the bioavailability of bioactive compounds.

Low β-carotene bioaccessibility and bioavailability from high fat, dairy-based meal.

The original aim of the study was to determine, in a double-blind 3-arm crossover human trial (n = 7), the effect of supplemental levels of iron (25mg) and zinc (30mg) on β-carotene (synthetic) bioavailability (10h postprandial). However, despite the high dose of supplemental β-carotene (15mg) consumed with the high fat (18g), dairy-based breakfast test meal, there was a negligible postprandial response in plasma and triglyceride rich fraction β-carotene concentrations. We then systematically investigated the possible reasons for this low bioavailability of β-carotene. We determined (1) if the supplemental β-carotene could be micellised and absorbed by epithelial cells, using a Caco-2 cell model, (2) if the fat from the test meal was sufficiently bioavailable to facilitate β-carotene bioavailability, (3) the extent to which the β-carotene could have been metabolised and converted to retinoic acid/retinol and (4) the effect of the test meal matrix on the β-carotene bioaccessibility (in vitro digestion) and Caco-2 cellular uptake. We found that (1) The supplemental β-carotene could be micellised and absorbed by epithelial cells, (2) the postprandial plasma triacylglycerol response was substantial (approximately 75-100mg dL-1 over 10h), indicating sufficient lipid bioavailability to ensure β-carotene absorption, (3) the high fat content of the meal (approximately 18 g) could have resulted in increased β-carotene metabolism, (4) β-carotene bioaccessibility from the dairy-based test meal was sixfold lower (p < 0.05) than when digested with olive oil. The low β-carotene bioavailability is probably due to a combination of the metabolism of β-carotene to retinol by BCMO1 and interactions of β-carotene with the food matrix, decreasing the bioaccessibility. The human trail was retrospectively registered (ClinicalTrail.gov ID: NCT05840848).

Chemical stability of β-carotene composite or bilayer emulsions coated with pea protein isolate and γ-polyglutamic acid compared to monolayer emulsion

Abstract The integration of β-carotene into functional foods is limited due to its limited hydrophilicity and chemical stability. To address this issue, emulsion was encouraged to be utilized. Monolayer, composite, and bilayer emulsions were prepared using pea protein isolate (PPI) alone or in combination with poly-γ-glutamic acid (γ-PGA). Our findings indicate that the bilayer emulsion utilizing γ-PGA as an external emulsifier exhibited the smallest droplet size (737.61 nm) and highest zeta potential (−35.23 mV). Under various environmental stresses, the chemical stability of the composite emulsion surpassed that of the monolayer emulsion but was inferior to that of the bilayer emulsion. Moreover, following simulated gastrointestinal digestion, the β-carotene bioaccessibility in the composite emulsion (12.76 %) exceeded that in the monolayer emulsion (6.57 %) but was less than that in the bilayer emulsion (20.01 %). Therefore, the emulsion preparation method or the sequence of γ-PGA addition significantly affects emulsion stability. Among the studied emulsions, the bilayer emulsion demonstrated the most stable structure, enhancing the stability of β-carotene within the oil droplets.

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.

Effects of co-assembly of gliadin and carboxymethyl cellulose on the high internal phase pickering emulsions: Rheology properties, 3D printing performance and oil-soluble nutrient delivery

High internal phase Pickering emulsions (HIPPEs) stabilized with gliadin-based particles have received considerable attention because of the advantages of easy access, low cost and clean label. However, the relatively weak self-supporting and thixotropic recovery properties limit their application in food 3D printing. The present study investigated the effects of co-assembly of gliadin and carboxymethyl cellulose (CMC) on the gel network structure, viscoelasticity, thixotropic recovery, 3D printing properties and β-carotene delivery performance of HIPPEs stabilized with gliadin-based colloid particles. The results showed that the combination of gliadin and CMC significantly enhanced the density of gel network structure of HIPPEs and endowed the HIPPEs solid-like viscoelasticity, moderate shear thinning behavior and excellent thixotropic recovery rate as well as 3D printability. The HIPPEs realized an optimal performance at a gliadin/CMC mass ratio of 2:1, with a thixotropic recovery rate up to 93.23 ± 0.72 %, and the corresponding printed 3D model had a smooth surface, regular shape, and good printing accuracy. In addition, the potential application of HIPPEs in delivery of oil-soluble nutrients was investigated using β-carotene as a model. The result suggested that the stability and bioaccessibility of β-carotene was significantly improved from 25.71 ± 0.29 % to 59.70 ± 0.99 % and 12.30 ± 0.11 % to 37.04 ± 0.76 % respectively as the existence of CMC. This study provides references for the construction and design of food 3D printing materials.

Inhibitory effects of chlorophyll pigments on the bioaccessibility of β-carotene: Influence of chlorophyll structure and oil matrix

Chlorophylls and β-carotene are fat-soluble phytochemicals in daily diets, while their bioaccessibility interaction remains unknown. Eight dietary chlorophylls and their derivatives (chlorophyll a, chlorophyll b, pheophytin a, pheophytin b, chlorophyllide a, chlorophyllide b, pheophorbide a, pheophorbide b) were combined with β-carotene in six different oil matrices (corn oil, coconut oil, medium-chain triglycerides, peanut oil, olive oil and fish oil) and were subjected to in vitro digestion. Generally, chlorophylls significantly decreased β-carotene bioaccessibility by competitive incorporation into micelles. Dephytylated chlorophylls had a greater inhibitory effect on the micellarization and bioaccessibility of β-carotene compared to phytylated chlorophylls. In their co-digestion system, olive oil group exhibited the smallest particle size and biggest zeta potential in both digesta and micelles. For chlorophylls, the phytol group and their levels are key factors, which was also buttressed by the mice model where additional supplementation of pheophorbide a significantly hindered the accumulation of β-carotene and retinoids compounds.

Carboxymethylcellulose-induced depletion attraction to stabilize high internal phase Pickering emulsions for the elderly: 3D printing and β-carotene delivery

In this study, a carboxymethylcellulose (CMC) induced depletion attraction was developed to stabilize high internal phase Pickering emulsions (HIPPEs) as age-friendly 3D printing inks. The results demonstrated that depletion force induced the adsorption of yolk particles at the droplet interface and the formation of osmotic droplet clusters, thereby increasing the stability of HIPPEs. In addition, the rheological properties and nutrient delivery properties of HIPPEs could be adjusted by the mass ratio of yolk/CMC. The HIPPEs stabilized at yolk/CMC mass ratio 20:7.5 showed optimal printability, viscoelastic, structural recovery, and swallowability. HIPPEs have been applied to 3D printing, International Dysphagia Dietary Standardization Initiative (IDDSI) test, and in vitro digestive simulation in the elderly, indicating their attractive appearance, safe swallowability, and enhanced bioaccessibility of β-carotene. Our work provides new ideas for developing age-friendly foods with plasticity and nutrient delivery capacity by depletion attraction stabilizing HIPPEs.

Encapsulation and protection of β-carotene in Pickering emulsions stabilized by chitosan-phytic acid-cyclodextrin nanoparticles

β-Carotene is a hydrophobic molecule that can be isolated from plants that acts as a natural pigmen and nutraceutical. However, the limited water-solubility, oxidative-stability, and bioavailability limit its utilization in functional food, supplement, and pharmaceutical products. Pickering emulsions stabilized by chitosan-phytic acid-cyclodextrin (CS-PA-CD) nanoparticles were prepared to improve the delivery, stability, and bioavailability of β-carotene. The impact of nanoparticle concentration (0.1%, 0.5%, 1.0%, 1.5%, 2.0% w/v) and oil phase fraction (30%, 40%, 50%, 60%, 70% v/v) on the stability of β-carotene-loaded Pickering emulsions was investigated. The Pickering emulsions that were most stable to phase separation were formed at intermediate oil concentrations (50%-60% v/v). The encapsulated β-carotene exhibited improved resistance to heating (70 °C) and UV light exposure. Moreover, the bioaccessibility of β-carotene was also improved using a simulated gastrointestinal model. Overall, our findings highlight the potential of CS-PA-CD nanoparticles for forming and stabilizing Pickering emulsion-based delivery carrier for hydrophobic bioactive substances.

Drum drying of whole maize flour enhances bioaccessibility of zeaxanthin, α-tocopherol, phytosterols, phenolics and flavonoids

The aim of the present study was to investigate the effect of drum drying of maize flour at slurry concentration of 30%–40% on phytonutrients content and their bioaccessibility. Content of tocopherols (TP), tocotrienol (TT), carotenoids, phytosterols, polyphenols and flavonoids, and antioxidant activity in drum dried maize was decreased. Bioaccessible content of stigmasterol, β-sitosterol and flavonoids was increased in drum dried maize. Bioaccessible content of campesterol and total phenolics was comparable to the bioaccessible content in raw maize. Bioaccessible content of TP, TT, lutein, zeaxanthin and β-carotene decreased in drum dried samples. DPPH + radical scavenging activity of bioaccessible fraction of drum dried maize was increased. The ferric reducing power was stable and total antioxidant activity decreased in bioaccessible fraction of drum dried sample. Percentage bioaccessibility of α-TP, phytosterols, zeaxanthin, phenolics, flavonoids and antioxidant activity was increased. Bioaccessibility of lutein and β-carotene retained, and γ-TP, δ-TP, α-, γ-, δ-TT decreased in drum dried sample. Overall, phytonutrients content was found to be low in drum dried samples, but there was retention of components in bioaccessible fraction which resulted higher percentage bioaccessibility of maize phytonutrients.

Role of pectin in the delivery of β-carotene embedded in interpenetrating emulsion-filled gels made with soy protein isolate

This study investigated the effects of different matrices on gel properties, lipid digestibility, β-carotene bioaccessibility, released free amino acids and gel network degradation. Microstructure studies have proven that sugar beet pectin/soy protein isolate-based emulsion-filled gel (SBP/SPI-E) with interpenetrating networks was formed. SBP/SPI-E exhibited higher hardness (2.67 N, p < 0.05) and released lesser free amino acids (269.48-μmol/g SPI) than soy protein isolate-based emulsion-filled gel (SPI-E) in simulated intestinal fluid (SIF); however, both had similar free amino acids contents in simulated colonic fluid. SBP has the potential to delay gel network degradation in SIF, as evidenced by the sugar stain strips of SDS-PAGE and microstructure observation. Furthermore, SBP/SPI-E and SPI-E exhibited similar β-carotene bioaccessibility in SIF, suggesting that SBP from composite gel could not affect the aforementioned bioaccessibility. The study provides useful information for the design of functional gels in the application of fat-soluble nutrient delivery.

The effects of carrot shape and oral processing behaviour on bolus properties and β-carotene bioaccessibility of raw carrots

The aim of this study was to investigate the effects of carrot shape (cube vs. julienne) and oral processing behaviour, specifically chewing time, on bolus properties and bioaccessibility of β-carotene in raw carrots. Participants (n = 20) consumed raw carrot cubes (15 × 15 × 15 mm, 4.2 g/bite) and raw carrot julienne (2 × 3 × 90 mm, 4.2 g/bite) with normal (cube: 20 s/bite; julienne: 28 s/bite) and short (cube: 10 s/bite; julienne: 14 s/bite) chewing time. Expectorated boli were collected and characterized for number and mean area of carrot bolus particles. The proportion of easily extractable β-carotene of the carrot bolus was taken as an approximate indicator of the potentially bioaccessible β-carotene. Longer chewing time resulted in significantly more and smaller carrot bolus particles, larger particle surface area (p < 0.01) and higher proportion of easily extractable β-carotene than shorter chewing of raw carrots of both shapes (Cube_Normal vs. Cube_Short: 29 ± 7 % vs. 23 ± 7 %; Julienne_Normal vs. Julienne Short: 31 ± 8 % vs. 26 ± 6 %, p < 0.05). Carrot shape significantly influenced number and size of bolus particles (p < 0.01) with carrot julienne generating more and smaller carrot bolus particles than carrot cubes. These differences in bolus properties between carrot julienne and cubes did not influence the proportion of easily extractable β-carotene (p > 0.05). We conclude that differences in oral processing behaviour and the corresponding differences in bolus properties produce only modest differences in β-carotene bioaccessibility of raw carrots regardless of carrot shape.

Effect of beta glucan coating on controlled release, bioaccessibility, and absorption of β-carotene from loaded liposomes.

Recently, the use of biopolymers as coating material to stabilise phospholipid-based nanocarriers has increased. One such class of biopolymers is the dietary fibre beta-glucan (βG). In this study, we developed and characterized beta-carotene (βC) loaded βG coated nanoliposomes (GNLs) to investigate the effect of βG coating on the stability, controlled release, bioaccessibility, diffusion and subsequent absorption of the lipophilic active agent. The size, charge (Z-potential), and FTIR spectra were measured to determine the physicochemical stability of GNLs. βG coating reduced the bioaccessibility, provided prolonged release and improved the antioxidant activity of the nanoliposomes. Multiple particle tracking (MPT) data suggested that βC-GNLs were less diffusive in porcine intestinal mucus (PIM). Additionally, the microviscosity of the PIM treated with GNLs was observed to be higher (0.04744 ± 0.00865 Pa s) than the PIM incubated with uncoated NLs (0.015 ± 0.0004 Pa s). An Ex vivo experiment was performed on mouse jejunum to measure the absorption of beta-carotene from coated (βC-GNLs) and uncoated nanoliposomes (βC-NLs). Data showed that after 2 hours, 27.7 ± 1.3 ng mL-1 of βC encapsulated in GNLs and 61.54 ± 3 ng mL-1 of the βC encapsulated in uncoated NLs was absorbed by mouse intestinal mucosa. These results highlight that coating with βG stabilise NLs during gastrointestinal digestion and provides more sustained release of βC from nanoliposomes.

Development of high internal phase Pickering emulsions stabilized by egg yolk and carboxymethylcellulose complexes to improve β-carotene bioaccessibility for the elderly

The work aimed to develop the multi-protein mixture of egg yolk as natural particles to stabilize high internal phase Pickering emulsions (HIPPEs) to improve the bioaccessibility of β-carotene in the elderly. The results showed that the depletion attraction drove the adsorption of egg yolk protein particles at the oil–water interface and the formation of osmotic droplet clusters due to the attachment of particle-coated droplets in the dispersed phase, leading to kinetic blocking and stable gelation of HIPPEs. Rheological measurements showed that HIPPEs had shear thinning, low shear stress, viscoelastic properties, and structural recovery properties, which facilitated easy consumption for the elderly. The stability of HIPPEs was verified by ionic and centrifugal stability tests, demonstrating their potential for application to complex gastric environments. HIPPEs have been applied to the International Dysphagia Dietary Standardization Initiative (IDDSI) test and simulated in vitro digestion in older adults, demonstrating their safe swallowability and high β-carotene bioaccessibility. Our findings suggest solutions for food practitioners facing the aging problem and provide new insights for preparing age-friendly foods.

Design of geometric structures of hydrogel via 3D printing to regulate release kinetics and bioaccessibility of β-carotene

The aim of the present study was to investigate release kinetics and bioaccessibility of β-carotene from four key geometric structures of hydrogel tablets, total porosity, filling porosity, average pore size and specific surface area, which constructed by 3D printing four shapes and three internal filling patterns. The results indicated that circle samples had the lowest filling porosity, average pore size and specific surface area, which showed the highest cumulative intestinal release amounts of β-carotene (CIA). While diagonal samples exhibited the higher total porosity, resulting in the higher cumulative gastric release amounts of β-carotene (CGA). Disintegration of hexagon and circle samples were clearly delayed compared square and pentagon samples. The β-carotene release was best fitted in the first order model in gastrointestinal digestion (r2, 0.9176–0.9915). The β-carotene release mechanism for all samples was Fickian diffusion and frame erosion in gastric digestion, while the predominant release mechanism of β-carotene for samples was Fickian diffusion in intestinal digestion except for hexagon and circle samples with orthogonal pattern. Positive correlations between CGA and negative correlations between CIA and geometric structural parameters of samples were obtained, and the correlation coefficients were found to be in the order: specific surface area > average pore size > total porosity > filling porosity. Circle samples and orthogonal samples had the higher β-carotene bioaccessibility of the printed tablets (38.75% ∼ 50.64%), and SVM model illustrated a better performance for predicting the β-carotene bioaccessibility of printing tablets based on structural parameters (R2 > 0.80).

Design, characterization and digestibility of β-carotene-loaded emulsion system stabilized by whey protein with chitosan and potato starch addition

The physicochemical properties and gastrointestinal fate of β-carotene-loaded emulsions and emulsion gels were examined. The emulsion was emulsified by whey protein isolate and incorporated with chitosan, then the emulsion gels were produced by gelatinizing potato starch in the aqueous phase. The rheology properties, water distribution, and microstructure of emulsions and emulsion gels were modulated by chitosan combination. A standardized INFOGEST method was employed to track the gastrointestinal fate of emulsion systems. Significant changes in droplet size, zeta-potential, and aggregation state were detected during in vitro digestion, including simulated oral, stomach, and small intestine phases. The presence of chitosan led to a significantly reduced free fatty acids release in emulsion, whereas a slightly increasing released amount in the emulsion gel. β-carotene bioaccessibility was significantly improved by hydrogel formation and chitosan addition. These results could be used to formulate advanced emulsion systems to improve the gastrointestinal fate of hydrophobic nutraceuticals.

High internal phase emulsions stabilized by pea protein isolate-EGCG-Fe3+ complexes: Encapsulation of β-carotene

Protein complexes have great potential for forming and stabilizing high internal phase emulsions (HIPEs) loaded with bioactive compounds. In this study, we investigated the potential of three types of complexes, namely pea protein isolate (PPI), PPI-epigallocatechin gallate (EGCG) and PPI-EGCG-Fe3+, to form and stabilize HIPEs with a 75% oil phase volume fraction. Initially, the impact of pH and emulsifier type on emulsions performance was investigated. Confocal laser scanning microscopy (CLSM) and particle size analysis showed that all three complexes could form HIPEs that remained stable under acidic and neutral conditions. These emulsions contained uniform oil droplets coated by a layer of the complexes. Notably, the PPI-EGCG-Fe3+ complexes formed HIPEs with the highest thermal and storage stability, which was attributed to the denser and thicker interfacial coatings. These emulsions also protected encapsulated β-carotene from degradation when exposed to light and thermal stress conditions. Furthermore, we measured lipid digestion and β-carotene bioaccessibility in the emulsions using an in vitro digestion model. The PPI-EGCG-Fe3+ stabilized emulsions not only exhibited slow fatty acid release but also enhanced β-carotene bioaccessibility (46.5%) under simulated small intestine conditions. This study demonstrates the potential of using protein-polyphenol-Fe3+ complexes to form and stabilize HIPEs, which may then be used to enhance the bioaccessibility and bioactivity of hydrophobic nutraceuticals.

Proteosomes based on milk phospholipids and proteins to enhance the stability and bioaccessibility of β-carotene.

Proteosomes (P) based on milk fat globule membrane's phospholipids (MPs), whey protein isolate (WPI) and sodium caseinate (CasNa) were developed by ultrasonication to encapsulate β-carotene. Entirely milk-ingredients based proteosomes (WPI-MPs-P and CasNa-MPs-P) revealed homogenous distribution with size diameters<250nm. WPI-MPs-P depicted positive ζ-potential values (+15.7±0.5mV), while CasNa-MPs-P demonstrated negative (-32.5±3.4mV) values of surface charge, respectively and hydrophilic nature of proteosomes was observed by measuring contact-angle (θ). AFM and SEM exhibited spherical to oval and slightly irregular morphology of nanocarriers. For various concentrations of β-carotene, the highest encapsulation efficiency of β-carotene was 90±0.2% and 92±0.8% in WPI-MPs-P and CasNa-MPs-P respectively. FTIR analyses confirmed the hydrophobic and electrostatic interactions-based encapsulation of β-carotene. Beneficial antioxidant-potential of β-carotene was retained after its encapsulation in the proteosomes. Proteosomes increased the digestive-stability (>50%) and bioaccessibility (>85%) of β-carotene. Thus, milk-ingredients based proteosomes offer a novel-strategy to develop functional dairy products to overcome widespread vitamin-A-deficiency.