Impact of iron encapsulation within the interior aqueous phase of water-in-oil-in-water emulsions on lipid oxidation

Iron (Fe³⁺) was encapsulated within the internal aqueous phase of water-in-oil-in-water (W/O/W) emulsions, and then the impact of this iron on the oxidative stability of fish oil droplets was examined. There was no significant change in lipid droplet diameter in the W/O/W emulsions during 7 days storage, suggesting that the emulsions were stable to lipid droplet flocculation and coalescence, and internal water diffusion/expulsion. The initial iron encapsulation (4 mg/100 g emulsion) within the internal aqueous phase of the water-in-oil (W/O) emulsions was high (>99.75%), although, a small amount leaked out over 7 days storage (≈10 μg/100 g emulsion). When W/O/W emulsions were mixed with fish oil droplets the thiobarbituric acid-reactive substances (TBARS) formed decreased (compared to fish oil droplets alone) by an amount that depended on iron concentration and location, i.e., no added iron < iron in external aqueous phase < iron in internal aqueous phase. These differences were attributed to the impact of W/O droplets on the concentration and location of iron and lipid oxidation reaction products within the system.     

Rheology and microstructure of myofibrillar protein-plant lipid composite gels: Effect of emulsion droplet size and membrane type

Composite gels were prepared from 2% myofibrillar protein (MP) with 10% imbedded pre-emulsified plant oils (olive and peanut) of various particle sizes at 0.6 M NaCl, pH 6.2. Dynamic rheological testing upon temperature sweeping (20-70 °C at 2 °C/min) showed substantial increases in G′ (elastic modulus) of MP sols/gels with the addition of emulsions, and the G′ increases were inversely related to the emulsion droplet size. Furthermore, gels containing emulsified olive oil had a greater (P < 0.05) hardness than those containing emulsified peanut oil. Regardless of oil types, MP-coated oil droplets exhibited stronger reinforcement of MP gels than Tween 80-stablized oil droplets; the latter composite gels had considerable syneresis. Light microscopy with paraffin sectioning revealed a stable gel structure when filled with protein-coated oil droplets, compared to gels with Tween 80-treated emulsions that showed coalesced oil droplets. These results suggest that rheological characteristics, hardness, texture, and water-holding capacity of MP gels were influenced by type of oils, the nature of the interfacial membrane, and the size of emulsion droplets.     

Influence of interfacial composition on oxidative stability of oil-in-water emulsions stabilized by biopolymer emulsifiers

The objective of this research was to evaluate the influence of storage pH (3 and 7) and biopolymer emulsifier type (Whey protein isolate (WPI), Modified starch (MS) and Gum arabic (GA)) on the physical and oxidative stability of rice bran oil-in-water emulsions. All three emulsifiers formed small emulsion droplets (d₃₂ < 0.5 μm) when used at sufficiently high levels: 0.45%, 1% and 10% for WPI, MS and GA, respectively. The droplets were relatively stable to droplet growth throughout storage (d₃₂ < 0.6 μm after 20 days), although there was some evidence of droplet aggregation particularly in the MS-stabilized emulsions. The electrical charge on the biopolymer-coated lipid droplets depended on pH and biopolymer type: −13 and −27 mV at pH 3 and 7 for GA; −2 and −3 mV at pH 3 and 7 for MS; +37 and −38 mV at pH 3 and 7 for WPI. The oxidative stability of the emulsions was monitored by measuring peroxide (primary products) and hexanal (secondary products) formation during storage at 37 °C, for up to 20 days, in the presence of a pro-oxidant (iron/EDTA). Rice bran oil emulsions containing MS- and WPI-coated lipid droplets were relatively stable to lipid oxidation, but those containing GA-coated droplets were highly unstable to oxidation at both pH 3 and 7. The results are interpreted in terms of the impact of the electrical characteristics of the biopolymers on the ability of cationic iron ions to interact with emulsified lipids. These results have important implications for utilizing rice bran oil, and other oxidatively unstable oils, in commercial food and beverage products.     

Effects of enzymatically modified starch on the encapsulation efficiency and stability of water-in-oil-in-water emulsions

The present study was performed to investigate the possibility of using 4-α-glucanotransferase (4αGTase)-treated starch in W/O/W emulsions to increase their encapsulation efficiency (EE) and stability. Emulsions were prepared using soybean oil, polyglycerol polyricinoleate (PGPR), 4αGTase-treated starch and Tween 20. The mean diameter of W/O/W droplets ranged from 4 to 10 μm depending on the sonication time. When the dye was loaded in the internal water phase, the emulsion prepared by sonication for 1 and 2 min showed a high EE of the dye (>90%). The W/O/W emulsion prepared by sonication for 3 min showed an EE of <90%, but this EE was improved by adding 4αGTase-treated starch to the internal water phase. 4αGTase-treated starch was added to the internal water phase of W/O/W emulsions prepared with a low concentration of PGPR, and the PGPR concentration required to maintain an EE >90% was reduced. W/O/W emulsions containing 4αGTase-treated starch also showed better stability against heating and shearing stresses. These results indicated that 4αGTase-treated starch could be used in the preparation of W/O/W emulsions, which would allow the formulation of W/O/W emulsions with a reduced surfactant concentration.     

Enhancing anti-inflammation activity of curcumin through O/W nanoemulsions

High-speed and high-pressure homogenized O/W emulsions using medium chain triacylglycerols (MCT) as oil and Tween 20 as emulsifier, with mean droplet sizes ranging from 618.6 nm to 79.5 nm, have been successfully prepared. The enhanced anti-inflammation activity of curcumin encapsulated in O/W emulsions is evidenced by the mouse ear inflammation model. There is a 43% or 85% inhibition effect of 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced edema of mouse ear for 618.6 nm and 79.5 nm 1% curcumin O/W emulsions, respectively, but a negligible effect is found for 1% curcumin in 10% Tween 20 water solution.     

Oxidative stability of soybean oil in oleosomes as affected by pH and iron

The oxidative stability of oil in soybean oleosomes, isolated using the Enzyme-Assisted Aqueous Extraction Process (EAEP), was evaluated. The effects of ferric chloride, at two concentration levels (100 and 500 μM), on lipid oxidation, was examined under pH 2 and 7. The peroxide value (PV) and thiobarbituric acid-reactive substance (TBARS) value of oil, in oleosome suspensions stored at 60 °C, were measured over a 12 day period. The presence of ferric chloride significantly (P < 0.05) affected the oxidative stability of oil in the isolated oleosome, as measured by the PV and TBARS. Greater lipid oxidation occurred under an acidic pH. In the pH 7 samples, the positively charged transition metals were strongly attracted to the negatively charged droplets. However, the low ζ-potential and the high creaming rate at this pH, may have limited the oxidation. Freezing, freeze–drying or heating of oleosomes have an insignificant impact on the oxidative stability of oil in isolated soybean oleosomes. Manufacturers should be cautious when adding oleosomes as ingredients in food systems containing transition metal ions.     

Inhibition of lipid oxidation by encapsulation of emulsion droplets within hydrogel microspheres

The purpose of this study was to assess whether the oxidation of polyunsaturated lipids could be inhibited by encapsulating them within protein-rich hydrogel microspheres (size range 1-100 μm). Filled hydrogel microspheres were fabricated as follows: (i) high methoxy pectin, sodium caseinate, and casein-coated lipid droplets were mixed at pH 7, (ii) the mixture was acidified (pH 5), (iii) casein was cross-linked using transglutaminase, (iv) the pH was adjusted to pH 7. Samples were stored in the dark at 55 °C and were monitored for lipid hydroperoxide formation and headspace propanal. Oxidation of fish oil (1% vol/vol) in the microspheres was compared with that in oil-in-water emulsions stabilised by either sodium caseinate or Tween 20. Emulsions stabilised by Tween 20 oxidised faster than either microspheres or emulsions stabilised by casein, while microspheres and the casein stabilised emulsion showed similar oxidation rates. Results highlight the natural antioxidant properties of food proteins.     

Structuring of lipid phases using controlled heteroaggregation of protein microspheres in water-in-oil emulsions

The effect of heteroaggregation of oppositely charged protein microspheres dispersed within a liquid oil phase on the microstructure and rheological properties of water-in-oil (W/O) emulsions was evaluated. The aqueous phase of the initial W/O emulsions contained either 10% β-lactoglobulin or 10% lactoferrin (pH 7, 100 mM NaCl). At this pH, β-lactoglobulin (BLG) is negatively charged while lactoferrin (LF) is positively charged. The oil phase consisted of a lipophilic non-ionic surfactant (8% polyglycerol polyricinoleate, PGPR) dispersed within soybean oil. Three 40% W/O emulsions were formed containing different types of protein microspheres: (i) BLG: 100% BLG droplets; (ii) LF: 100% LF droplets; and (iii) Mixed: 50% BLG droplets and 50% LF droplets. Prior to heating, the mixed emulsions had a higher shear viscosity, yield stress, and shear modulus than the BLG or LF emulsions, which suggested that electrostatic attraction led to the formation of a three-dimensional network of aggregated droplets. All three W/O emulsions underwent an irreversible fluid-to-solid transition when they were heated above ≈70 °C. This phenomenon was attributed to thermal denaturation of the globular BLG and LF molecules within the aqueous phase promoting aggregation and network formation of the protein microspheres. After heating, the mixed emulsions had a higher shear viscosity, yield stress and shear modulus than the BLG or LF emulsions, suggesting that a stronger droplet network was formed due to electrostatic attraction. Shear rheology measurements of the W/O emulsions showed that the lipid phases formed after heating were non-ideal plastics characterized by a yield stress and shear thinning behavior. These results may facilitate the design of semi-solid or solid foods with reduced saturated- or trans-fat contents suitable for use in commercial products.     

Improvement of physicochemical stabilities of emulsions containing oil droplets coated by non-globular protein-beet pectin complex membranes

The potential of beet pectin for improving the physical and chemical stabilities of emulsions containing silk fibroin coated droplets was investigated. Five wt.% corn oil-in-water emulsions containing fibroin-coated droplets (0.5 wt.% fibroin) and anionic pectin (0.05 wt.%) were prepared at pH 7. The pH of these emulsions was then adjusted to pH 4, so that the anionic pectin molecules electrostatically deposited to the fibroin-coated droplets. The influence of pH (3 to 7) and sodium chloride concentrations (0 to 500 mM) on the properties of primary (0 wt.% pectin) and secondary (0.05 wt.% pectin) emulsions was studied. Pectin was deposited to the droplet surfaces at pH 3, 4, and 5, but not at pH 6 and 7. In addition, secondary emulsions were stable up to higher ionic strengths (< 500 mM) than primary emulsions (< 200 mM). The addition of beet pectin also prolonged the lag phase of lipid oxidation in the emulsions as determined by the formation of lipid hydroperoxides and headspace hexanal. The controlled electrostatic deposition method utilized in this study could be used to extend the range of application of silk fibroin in the industry.     

Effects of chlorophyll photosensitisation on the oxidative stability in oil-in-water emulsions

Effects of chlorophyll photosensitisation on the oxidative stability of oil-in-water (O/W) emulsions were determined by analysing headspace oxygen content, lipid hydroperoxides, and headspace volatiles. The roles of transition metals and singlet oxygen were tested by adding ethylenediaminetetraacetic acid (EDTA) and sodium azide, respectively. Emulsions with chlorophylls and visible light irradiation had significantly high lipid hydroperoxides and headspace volatiles and low headspace oxygen content (p < 0.05) after 32 h while samples without light irradiation did not show any significant changes (p > 0.05). Sodium azide did not show clear antioxidant capacities in O/W emulsion systems rather showed prooxidant properties at some concentration. Addition of EDTA, a metal chelator, accelerated the rates of lipid oxidation in a concentration dependent manner. EDTA may enhance the stability of chlorophylls in O/W emulsions and the resulting higher chlorophyll concentrations may generate more singlet oxygen thus accelerating the rates of lipid oxidation.     

Oxidative stability and total lipids on thigh and breast meat of broilers fed diets with two fat sources and supplemented with conjugated linoleic acid

Two hundred broiler chickens of 21 days of age were distributed in a completely randomized factorial arrangement 2×5 (two oil sources, i.e. soybean or canola oil and five levels of CLA supplementation, i.e. 0.0%, 0.25%, 0.50%, 0.75% and 1.00%). The purpose of this study was to evaluate the dietary supplementation of broiler diets with CLA and oil sources on the lipid content and on the oxidative stability of chicken meat submitted to refrigeration or freezing storage temperatures. The use of canola oil and increasing CLA levels resulted in a linear reduction (P<0.05) on the total lipids in breast meat. These results can explain a linear reduction (P<0.05) observed in the malonaldehyde content of refrigerated and frozen meat of birds receiving canola oil. Birds receiving soybean oil and supplemented with CLA showed an abrupt reduction of total lipids on breast meat from 0.89 g/100 g at 0% CLA to 0.36 g/100 g at 0.5% CLA followed by a small increase at higher levels of CLA (P<0.05). These observations may help to explain the reduction (P<0.05) of oxidation in breast meat during frozen storage at 50 and 100 days as well as during cold storage at 5 °C.     

Effect of tannic acid and kiam wood extract on lipid oxidation and textural properties of fish emulsion sausages during refrigerated storage

Effect of tannic acid (0.02% and 0.04%) and ethanolic kiam wood extract (EKWE) (0.04% and 0.08%) on lipid oxidation and textural properties of fish emulsion sausages during 20 days of refrigerated storage was investigated. Control samples (C) had the highest peroxide value (PV) and thiobarbituric acid-reactive substances (TBARS) value up to day 16 and 8 of storage, respectively. With the addition of tannic acid and EKWE, PV and TBARS values in the sausages were retarded effectively, compared to the control (P < 0.05), especially when the tannic acid and EKWE at higher level were used. At the same level, EKWE showed the lower ability in retarding the lipid oxidation, in comparison with tannic acid. Tannic acid at both levels (0.02% and 0.04%) was also effective in retarding the formation of fishy odour in the samples throughout the storage, compared to the control and EKWE treated samples (P < 0.05). Both tannic acid and EKWE had no detrimental effect on the sensory attributes of sausages. However, EKWE treated sample had lower L^∗ and higher a^∗ and ΔE^∗ values, compared to the control samples (P < 0.05). After 20 days of storage, the sample added with 0.04% tannic acid had higher hardness, gumminess and chewiness, compared with others (P < 0.05). Samples added with 0.04% tannic acid also displayed more compact structure with no visible voids. Furthermore, oil droplets with smaller size were dispersed more uniformly, compared to others. Thus, tannic acid (0.02% and 0.04%) and EKWE (0.08%) were effective in retarding lipid oxidation and fishy odour development as well as could maintain the textural properties of fish emulsion sausages during the refrigerated storage of 20 days.     

Effect of chitosan on the stability and properties of modified lecithin stabilized oil-in-water monodisperse emulsion prepared by microchannel emulsification

The effect of chitosan (CHI) on the stability of monodisperse modified lecithin (ML) stabilized soybean oil-in-water (O/W) emulsion was investigated. Monodisperse emulsion droplets with particle size of 24.4 ± 0.7 μm and coefficient of variation below 12% were prepared by microchannel (MC) emulsification using a hydrophilic asymmetric straight-through MC silicon 24 × 24 mm microchip consisting of 23,348 microchannels. The stability of the ML stabilized monodisperse emulsion droplets was investigated as a function of CHI addition at various concentration, pH, ionic strength, thermal treatment and freezing-thawing treatment by means of particle size and ζ-potential measurements as well as microscopic observation. The monodisperse O/W emulsions were diluted with CHI solution at various concentrations to a final droplet concentration of 1 wt% soybean oil, 0.25 wt% ML and 0–0.5 wt% CHI at pH 3. Pronounced droplet aggregation was observed when CHI was present at a concentration range of between 0.01 and 0.04 wt%. Above this concentration range, flocculations were less extensive, indicating some restabilization. ML stabilized emulsions were stable at a wide range of NaCl concentrations (0–1000 mM) and pH (3–8). On the contrary, in the presence of CHI, aggregation of the emulsion droplets was observed when NaCl concentration was above 200 mM and when the pH started to approach the pKa of CHI (i.e. ∼6.2–7.0). Emulsions containing CHI were found to have better stability at high temperature (>70 °C) in comparison to the emulsion stabilized only by ML. With sucrose/sorbitol as cryoprotectant aids, emulsions with the addition of CHI were found to be more resistant to droplet coalescence as compared to those without CHI after freezing at −20 °C for 22 h and thawing at 30 °C for 2 h. The use of CHI may potentially destabilize ML-stabilized O/W emulsions but its stability can be enhanced by selectively choosing the appropriate CHI concentrations and conditions of preparation.     

马铃薯蛋白水解物对不同乳化剂制备O/W乳状液氧化稳定性的影响

用Fenton催化氧化体系模拟氧化,催化剂FeCl3,H2O2,VC的浓度分别为5、5、0.1mmol/L,以脂肪氧化产物丙二醛为指标,考察了马铃薯蛋白和不同乳化剂(非离子乳化剂Tween20、阴离子乳化剂卵磷脂和大分子乳化剂酪蛋白酸钠)共乳化制备得到的乳状液的氧化稳定性,并测定了相应乳状液的乳化稳定性。酪蛋白酸钠和马铃薯水解蛋白作为乳化剂得到的乳状液氧化稳定性较好,而Tween20和马铃薯蛋白水解物作为乳化剂得到的乳状液物理稳定性较高。     

Free-radical scavenging and antioxidative activities of some polysaccharides in emulsions

The antioxidant activity in linoleate emulsion systems, radical scavenging activity and inhibition of autoxidation in sunflower oil-in-water emulsions were studied in the presence of polysaccharide produced by Rhizobium meliloti (RPS), xanthan, curdlan, and carboxymethylcellulose (CMC) and compared to tertiary butylhydroxyquinone (TBHQ). The antioxidant activity in the linoleate emulsion was improved with increasing pH from 3 to 9 and concentration of polysaccharide from 20 to 60 mg/100 g emulsion, while it decreased with increase in storage temperature between 30 and 90 °C. The antioxidant activity of xanthan, curdlan, and RPS at concentration of 40 mg/100 g emulsion was equal to that of TBHQ at 20 mg/100 g emulsion. RPS showed the highest thermal stability and the lowest linoleic oxidation values compared to TBHQ, xanthan, and curdlan at 90 °C. The antioxidant activity of xanthan, curdlan, and RPS in linoleate emulsions at pH 3 and 5 was in the first order with significant (P<0.05) values compared to emulsion, prepared using TBHQ.Curdlan and RPS were effective in radical scavenging being 60-90% at pH values ranging between 3 and 7. They showed an ability to inhibit lipid oxidation in sunflower oil emulsions during holding time for 50 h at 60 °C. In general, the polysaccharides RPS and curdlan can be used as food additives having many functions as stabilizers, radical scavengers, and antioxidants in emulsified foods such as mayonnaise, salad dressings, and cake products.     

Stability of potassium iodide and omega-3 fatty acids in fortified freshwater fish emulsion sausage

Oxidative stability of emulsion sausages prepared from African walking catfish (AF: Clarias gariepinus) and rohu (RH: Labeo rohita) fortified with three levels of the refined tuna oil (2%, 6%, and 10%) with 150 μg KI/100 g sample and without KI was investigated. The control was prepared using 20% soybean oil and without KI. Samples were vacuum-packed and stored at 4 °C. Iodine content decreased approximately 14% after cooking and remained constant throughout storage. Sausages fortified with tuna oil showed higher level of n-3 (eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)), but lower level of n-6 fatty acids (P<0.05) than the control. The ratio of n-6 to n-3 fatty acids of all samples decreased with an increase of tuna oil addition and was stable throughout 4 weeks of storage. Degradation of linoleic (LA) and linolenic acid (LNA) mainly occurred in the samples added 2% tuna oil whereas samples fortified with higher tuna oil (6-10%) exhibited higher loss of EPA and DHA. Hydroperoxide (HPV) and thiobarbituric reactive substances (TBARS) values were increased as addition level of tuna oil increased. Textural properties were not affected during storage at 4 °C for up to 4 weeks (P<0.05). Based on lipid stability results, 2% fortification of the refined tuna oil was recommended for emulsion sausage prepared from both species. Addition of 150 μg KI/100 g had no effect on lipid oxidation of fish sausages (P<0.05).     

Impact of salt and lipid type on in vitro digestion of emulsified lipids

This study examined the effects of oil type and NaCl addition on the micro-structural changes that occur to emulsified lipids as they pass through a model gastrointestinal tract (GIT). Oil-in-water emulsions stabilized by a non-ionic surfactant (Tween 20) were prepared using different kinds of lipids (3% soybean oil, corn oil, olive oil or lard). The emulsified lipids were passed through an in vitro digestion model that simulated the composition (pH, minerals, surface active components, and enzymes) of the human GIT. Prior to digestion, emulsified lipid droplets appear to be bridging flocculation in 1% NaCl added emulsified lipids, moreover lipid droplets of 1% NaCl added emulsified lipids seems to be more disrupted than no NaCl added emulsified lipids. Mean particle size prepared with lard was smaller than those of other emulsified lipids. Free fatty acid contents increased after in vitro digestion in all emulsified lipids. Especially, free fatty acid content of emulsified lipid made from lard and olive oil were significantly higher than those of other emulsions after in vitro digestion.     

乳化体系中花生油氧化稳定性的研究

主要探讨花生油乳化体系中乳化剂类型、用量、pH值、EDTA、温度等对花生油氧化稳定性的影响,结果显示:乳化剂种类和pH对于乳状液体系的氧化稳定性有显著影响,阴离子乳化剂SDS稳定的乳化液,pH4.0的氧化速率最快;非离子乳化剂Tween20稳定的乳化液,pH的影响不是很显著;阳离子乳化剂CTAB稳定的乳化液,随着pH的升高,氧化速率变快。乳化液体系中微量金属离子对于体系也有相当大的影响,随着金属离子螯合剂EDTA浓度的增加,其乳化体系中花生油的氧化速率显著降低。乳化剂用量也会影响体系的氧化稳定性,随着乳化剂用量的增加,乳化乳化体系中花生油的氧化稳定性降低。     

Effects of Green Tea Extract and α‐Tocopherol on the Lipid Oxidation Rate of Omega‐3 Oils,Incorporated into Table Spreads,Prepared using Multiple Emulsion Technology

Abstract: This study examined the effectiveness of fat and water soluble antioxidants on the oxidative stability of omega (ω)‐3 rich table spreads, produced using novel multiple emulsion technology. Table spreads were produced by dispersing an oil‐in‐water (O/W) emulsion (500 g/kg 85 camelina/15 fish oil blend) in a hardstock/rapeseed oil blend, using sodium caseinate and polyglycerol polyricinoleate as emulsifiers. The O/W and oil‐in‐water‐in‐oil (O/W/O) emulsions contained either a water soluble antioxidant (green tea extract [GTE]), an oil soluble antioxidant (α‐Tocopherol), or both. Spreads containing α‐Tocopherol had the highest lipid hydroperoxide values, whereas spreads containing GTE had the lowest (P < 0.05), during storage at 5 °C, while p‐Anisidine values did not differ significantly. Particle size was generally unaffected by antioxidant type (P < 0.05). Double emulsion (O/W/O) structures were clearly seen in confocal images of the spreads. By the end of storage, none of the spreads had significantly different G′ values. Firmness (Newtons) of all spreads generally increased during storage (P < 0.05). Practical Application: Lipid oxidation is a major problem in omega‐3 rich oils, and can cause off‐odors and off‐flavors. Double emulsion technology was used to produce omega‐3 enriched spreads (O/W/O emulsions), wherein the omega‐3 oil was incorporated into the inner oil phase, to protect it from lipid oxidation. Antioxidants were added to further protect the spreads by reducing lipid oxidation. Spreads produced had good oxidative stability and possessed functional (omega‐3 addition) properties.     

Protein-stabilized emulsions containing beta-carotene produced by premix membrane emulsification

Protein-stabilized O/W emulsions containing beta-carotene were produced by premix membrane emulsification (ME) using polymeric microfiltration membranes. Bovine serum albumin (BSA) and a whey protein concentrate (WPC) were used as protein emulsifiers while a nonionic small-molecule surfactant, Tween 20, was used both as a control and co-emulsifier. Membrane fouling caused by WPC reduced more significantly transmembrane flux than that by BSA. Mixtures of WPC or BSA with Tween 20 reduced protein membrane fouling and, simultaneously, decreased the mean droplet size. WPC/Tween 20 mixtures enable to produce emulsions with low polydispersion (span < 1) but with a significant membrane fouling while BSA/Tween 20 mixtures led to higher transmembrane fluxes although polydisperse emulsions (span = 7). During storage at 22 and 35 °C, the chemical degradation rate of emulsions with WPC/Tween 20 was slower than those with BSA/Tween 20 whereas Tween 20-stabilized emulsions led to the highest rate of beta-carotene reduction during storage at 35 °C.