Ultrasound-mediated host-guest self-assembly between different dietary fatty acids and sodium caseinate and their complexes improving the water dispersibility, stability, and bioaccessibility of quercetin.

Quercetin (QUE) sufferred from poor processing adaptability and absorbability, hindering its application as a dietary supplement in the food industry. In this study, fatty acids (FAs)-sodium caseinate (NaCas) ligand complexes carriers were fabricated to improve the aqueous dispersibility, storage/thermal stability, and bioaccessibility of QUE using an ultrasound method. The results indicated that all six selected common dietary FAs formed stable hydrophilic complexes with NaCas and the FAs-NaCas complexes achieved an encapsulation efficiency greater than 90 % for QUE. Furthermore, the introduction of FAs enhanced the binding affinity between NaCas and QUE, but did not change the binding mode (static bursting) and types of intermolecular forces (mainly hydrogen bonding). In addition, a distinct improvement was discovered in the storage stability (>2.37-fold), thermal processing stability (>32.54 %), and bioaccessibility (>2.37-fold) of QUE. Therefore, the FAs-NaCas ligand complexes could effectively protect QUE to minimize degradation as fat-soluble polyphenol delivery vehicles.

Lutein bioaccessibility in casein-stabilized emulsions is influenced by the free to acylated carotenoid ratio, but not by the casein aggregation state.

Considering that carotenoids are found acylated to fatty acids in most edible fruits, the influence of the ratio of free to acylated lutein on the hydrolysis extent and bioaccessibility was evaluated by in vitro digestion. For this purpose, for the first time, esterified, free, or a mixture of both carotenoid forms was used in the lipid phase of emulsions stabilized by sodium caseinate (NaCas) and native phosphocaseinate (PPCN). Marigold petals was used as a source of lutein-rich extracts. The emulsions were characterized and the extent of ester hydrolysis, carotenoid recovery, and bioaccessibility were evaluated by LC-DAD-MS/MS. Besides low polydispersity, NaCas and PPCN stabilized emulsions exhibited a constant mean droplet diameter of about 260 and 330 nm, respectively, after 7 days. Caseins were completely digested after the gastric digestion step. Moreover, casein supramolecular structure did not significantly affect carotenoid bioaccessibility. Lutein was majorly found in its free form in all bioaccessible fractions. The carotenoid bioaccessibility increased from 3% to 40% by increasing the percentage of free carotenoids from 0.5 to 100% in the emulsions; but the carotenoid recovery and hydrolysis extent of lutein esters were not affected. In conclusion, emulsion-based systems for carotenoid delivery stabilized either by NaCas or PPCN provided similar carotenoid bioaccessibility. Furthermore, bioaccessibility was inversely dependent on the overall hydrophobicity of the carotenoid extract. Our results suggest that the low bioaccessibility of esterified carotenoids was a consequence of their limited hydrolysis extent. This study provides information that may help design emulsion-based systems stabilized by food protein as a vehicle for carotenoids.

Resveratrol inhibits lipid and protein co-oxidation in sodium caseinate-walnut oil emulsions by reinforcing oil-water interface.

Lipid-protein co-oxidation often causes nutrition loss, texture changes, and shortened shelf-life of emulsions. In this study, resveratrol significantly prevented lipid-protein co-oxidation in sodium caseinate (NaCas)-walnut oil emulsions, and the underlying mechanisms were explored in physical and chemical aspects. NaCas-walnut oil emulsions stabilized by resveratrol exhibited excellent physical stability at 55 °C for 12 days or at room temperature for 10 months due to forming a stable interfacial layer composed of resveratrol-modified NaCas. Furthermore, resveratrol binding caused NaCas structure's partial unfolding and a âˆ¼ 8% increase in hydrophobicity, in turn enhancing NaCas' emulsification properties and electrostatic repulsion. Besides, more than 90% of resveratrol was loaded at the interface and enhanced NaCas' Fe2+ chelating, DPPH scavenging abilities, and O2 quenching by âˆ¼ 22.6%, 5.26 times, and 31.84%, respectively. Simultaneously, resveratrol significantly improved NaCas' oxidative stability, as reflected by the decrease in adsorbed NaCas' intrinsic fluorescence loss and protein carbonyls gain by âˆ¼ 30% and 37%, respectively. Simultaneously, lipid hydroperoxides and TBARS were reduced by âˆ¼ 30% and 20% in the NaCas-walnut oil emulsions containing 6 mM resveratrol than the control. Our findings contribute to further understanding of the possible interaction among lipid, protein, polyphenols, and their oxidative products at the oil-water interface, minimizing lipid-protein co-oxidation and extending functional oils' shelf life. Finally, walnut oil emulsions with high physical and oxidative stabilities using resveratrol were prepared, further broadening resveratrol's application in the food industry.

Effect of pectin on the properties of nanoemulsions stabilized by sodium caseinate at neutral pH.

The effect of different concentrations of low methoxyl pectin (LMP) on lipid oxidation and physical stability of sodium caseinate (CAS) stabilized nanoemulsions under neutral pH was investigated. The addition of pectin at low concentration (≤ 0.10 wt%) had no significant effect on the average size of nanoemulsions, but a slight size increase and phase separation were observed at higher concentrations of pectin (≥ 0.25 wt%). This result suggests that LMP can not adsorb at the oil/water interfacial CAS membrane at neutral pH. However, in the presence of LMP, the physical stability of nanoemulsions against high salt concentrations and freeze-thaw cycles was significantly enhanced. Moreover, nanoemulsions containing pectin have a better ability to inhibit lipid and protein oxidation than nanoemulsions without pectin after 3 weeks, and the lowest lipid hydroperoxide content was observed for nanoemulsions containing 0.25 wt% pectin.

Sodium caseinate enhances the effect of konjac flour on delaying gastric emptying based on a dynamic in vitro human stomach-IV (DIVHS-IV) system.

BACKGROUND: In the context of the increasing prevalence of overweight and obesity worldwide, satiety-enhancing foods may help people control their energy intake and weight. In this study, an advanced near-real human gastric simulator equipped with a dynamic in vitro human stomach-IV (DIVHS-IV) system was used to determine the gastric digestion and gastric retention ratio of konjac flour (KF)/sodium caseinate (SC) mixtures with different ratios. RESULTS: The apparent viscosity, viscoelastic properties, confocal laser scanning microscopy (CLSM) of the digested products were collected and analyzed to further study the effect of SC on the physical properties of KF during digestion. The results showed that the addition of SC could enhance the effect of KF on delaying gastric emptying in vitro. Besides, the addition of SC was shown to weaken the effect of gastric juice on the dilution of gastric contents by forming SC gel blocks in the acid environment. In particular, the synergistic gastric emptying delaying effect was the strongest in the KF/SC mixture containing 1% KF and 8% SC, and obvious massive aggregates were observed. CONCLUSION: The combination of 1% KF and 8% SC was shown to synergistically delay gastric emptying and potentially enhance the sense of fullness. © 2022 Society of Chemical Industry.

Improving the functionality of chitosan-based packaging films by crosslinking with nanoencapsulated clove essential oil.

The study aimed to obtain chitosan composite films with gratifying physical and functional properties. First, we developed a Pickering emulsion containing clove essential oil (CEO)-loaded nanoparticles with 1:2 (w/w) zein and sodium caseinate (NaCas). We found that in this ratio, the CEO-loaded zein-NaCas (C/ZN) nanoparticles had smaller particle size, proper polydispersity index (PDI) and zeta potential as well as higher encapsulation efficiency. Then, the acquired C/ZN nanoparticles were incorporated into chitosan film at three levels (0.2%, 0.4% and 0.6%), reducing the water vapor permeability to 4.62 × 10-6 g·s-1·m-1·Pa. Also, the tensile strength and break elongation of chitosan films were increased, reaching 38.67 MPa and 1.56%, respectively. The infrared spectroscopy verified that the intermolecular hydrogen bonds exist between chitosan and C/ZN nanoparticles. The chitosan composite films showed a controlled-release property of CEO in 96 h. Finally, the chitosan composite films showed the improved antibacterial property by creating larger inhibition zones against Escherichia coli (3.29 mm) and Staphylococcus aureus (6.15 mm). In general, we improved the water resistance, light blocking, mechanical strength, controlled-release and antibacterial properties of chitosan film with C/ZN nanoparticles. The current edible antibacterial films have great potential on applications for food preservation and food delivery system.

Creaming behavior prediction of argan oil in water emulsion stabilized by lacto-fermentation: creaming index.

BACKGROUND: In order to improve the taste acceptability of certain nutritional oils, it has been decided in this study to introduce them in an emulsion whose surfactant is casein, then to carry out a lacto-fermentation, leading to a dairy-like product with added nutritional value and health benefit. In this context, a plan of mixtures has been proposed for the preparation of emulsions based on argan oil, sodium caseinate and starch, with concentrations ranged between (10-20%) and (0-2%) and (0-1.5%) respectively. All emulsions were homogenized at two high stirring velocities (10,000-20,000 rpm) and two stirring times (5-20 min). The physical stability was assessed by visual analysis and microstructural measurements. The Creaming index was calculated for selected emulsions to predict their creaming behavior. RESULTS: All emulsions showed a creaming behavior except one emulsion that required the highest values of all factors, which showed the highest creaming index with an average particle size of 11.27 µm. The absence or the variation of one or all factors led to various degrees of instabilities verified in all other emulsions. Due to the synergistic action of all parameters, the emulsion stability was attributed to the reduction of droplets size, the increase of continuous phase viscosity and the decrease of coalescence. CONCLUSION: The parameters that played a major role in the stability of the emulsion consists of: stirring velocity and time, sodium caseinate/oil ratio and starch/sodium caseinate ratio. The underlying structure and the interaction of the fluid droplets within the solid like product is what holds the stability of the product against settling or separation during fermentation.

Development and Characterization of Functional Starch-Based Films Incorporating Free or Microencapsulated Spent Black Tea Extract.

Antioxidant polyphenols in black tea residue are an underused source of bioactive compounds. Microencapsulation can turn them into a valuable functional ingredient for different food applications. This study investigated the potential of using spent black tea extract (SBT) as an active ingredient in food packaging. Free or microencapsulated forms of SBT, using a pectin-sodium caseinate mixture as a wall material, were incorporated in a cassava starch matrix and films developed by casting. The effect of incorporating SBT at different polyphenol contents (0.17% and 0.34%) on the structural, physical, and antioxidant properties of the films, the migration of active compounds into different food simulants and their performance at preventing lipid oxidation were evaluated. The results showed that adding free SBT modified the film structure by forming hydrogen bonds with starch, creating a less elastic film with antioxidant activity (173 and 587 µg(GAE)/g film). Incorporating microencapsulated SBT improved the mechanical properties of active films and preserved their antioxidant activity (276 and 627 µg(GAE)/g film). Encapsulates significantly enhanced the release of antioxidant polyphenols into both aqueous and fatty food simulants. Both types of active film exhibited better barrier properties against UV light and water vapour than the control starch film and delayed lipid oxidation up to 35 d. This study revealed that starch film incorporating microencapsulated SBT can be used as a functional food packaging to protect fatty foods from oxidation.

Enhanced water dispersibility and permeability through a Caco-2 cell monolayer of ß-cryptoxanthin extracted from kumquats by complexation with casein.

ß-Cryptoxanthin (BCX) possesses potential therapeutic and health benefits. However, BCX absorption is low because of its poor aqueous solubility. In this study, a complex between BCX and casein (Cas) was prepared to improve the water dispersibility and bioavailability of BCX. BCX was recovered quantitatively from freeze-dried kumquat powder through solid-liquid extraction and saponification. The complexation significantly improved the apparent solubility of BCX under acidic and neutral conditions. A cell membrane permeation test using a Caco-2 cell monolayer was performed to evaluate the bioavailability of the BCX-Cas complex. This complex and a blank sample were digested in vitro and added to the apical side of the Caco-2 cell membrane. The quantity of BCX that permeated using the BCX-Cas complex after 24 h was 22.7 times greater than that of the blank. Thus, complexation of BCX with Cas improved dramatically the bioavailability of BCX from a kumquat extract.

Enhancing the oxidative stability of algal oil emulsions by adding sweet orange oil: Effect of essential oil concentration.

The effects of sweet orange essential oil (SOEO) concentration (0-12.5% of oil phase) on the physical stability, oxidative stability, and interfacial composition of algal oil-in-water emulsions containing sodium caseinate-coated oil droplets was examined. SOEO addition had no influence on the microstructure and physical stability of the algal oil emulsions. The addition of SOEO enhanced the oxidation stability of algal oil emulsion. As an example, the values of algal oil emulsions with 0 and 10% SOEO were 198 and 100 mmol/kg algal oil after 16 days of accelerated oxidation, respectively. The absorbed protein level was higher in the algal oil emulsion containing 10% SOEO (70%) than in 0% SOEO (57%). This result suggested that the presence of SOEO enhanced the interfacial thickness, possibly by interacting with the casein molecules. A thicker protein layer may have helped to retard the oxidation of the omega-3 oils inside lipid droplets.

Physicochemical and structural characterization of sodium caseinate based film-forming solutions and edible films as affected by high methoxyl pectin.

Present work focused on the role of high methoxyl pectin (HMP) in rheology and physical stability of sodium caseinate (CAS) film-forming solution as well as mechanical and structural characteristics of its edible film. CAS-HMP films were fabricated at different blend ratio. Incorporation of HMP into CAS solution decreased pH value of the solution, acting as a natural acidifier. Turbidity and particle size distribution measurements indicated that some level of protein-polysaccharide interactions developed in 50CAS:50HMP and 25CAS:75HMP. Analysis of steady-state shear viscosity of film solutions showed a transition from Newtonian to shear-thinning flow behaviour by addition of HMP. Dynamic viscoelasticity evaluations revealed that the elasticity of solutions decreased by increasing HMP ratio. Physical stability of solutions was assessed over time using a Turbiscanner. All solutions showed distinct mechanisms of destabilization. 50CAS:50HMP and 25CAS:75HMP samples appeared to be the most stable solutions. Increasing CAS:HMP ratio from 100:0 to 25:75 increased the water solubility and elongation at break of edible films from 27.16 to 63.70% and 2.36 to 16.53%, respectively. SEM analysis exhibited a homogenous microstructure in 50CAS:50HMP and 25CAS:75HMP. DSC thermograms displayed lower glass transition temperatures in HMP-incorporated films. Presence of the interactions among biopolymers in biocomposites was confirmed by FTIR spectra.

Protein-Stabilized Palm-Oil-in-Water Emulsification Using Microchannel Array Devices under Controlled Temperature.

Microchannel (MC) emulsification for the preparation of monodisperse oil-in-water (O/W) and water-in-oil-in-water (W/O/W) emulsions containing palm oil as the oil phase was investigated for application as basic material solid/semi-solid lipid microspheres for delivery carriers of nutrients and drugs. Emulsification was characterized by direct observation of droplet generation under various operation conditions, as such, the effects of type and concentration of emulsifiers, emulsification temperature, MC structure, and flow rate of to-be-dispersed phase on droplet generation via MC were investigated. Sodium caseinate (SC) was confirmed as the most suitable emulsifier among the examined emulsifiers, and monodisperse O/W and W/O/W emulsions stabilized by it were successfully obtained with 20 to 40 µm mean diameter (dm) using different types of MCs.

Impact of sodium caseinate, soy lecithin and carrageenan on functionality of oil-in-water emulsions.

Oil-in-water emulsions are the main component of creamers, which are used to cream cold or hot coffee. These emulsions must provide the required lightening power and remain physically stable when introduced into hot acidic coffee solutions. In this study, model oil-in-water emulsions stabilized with mixed emulsifiers of sodium caseinate (0.5%) and soy lecithin (0.5%) were fabricated and their physical properties were examined over a range of pH values (pH 3.5 to 7). These model oil-in-water emulsions had strong lightening power (L* ≈ 87) and good physical stability from pH 5.5 to 7 but were unstable to gravitational separation below pH 5 due to caseinate aggregation around its isoelectric point. Addition of λ-carrageenan (0.05 to 0.175%) to the formulations prior to homogenization effectively improved their pH stability, while addition of κ-carrageenan was ineffective. The significantly higher level of sulfated ester groups in λ-carrageenan may have created a strong electrostatic repulsion between the oil particles, inhibiting their association. Our study suggests that some of the caseinate in coffee creamers can be replaced with plant-based lecithins, but that a plant-based polysaccharide is also needed to ensure their stability when added to hot acidic coffees.

Spray-drying of protein/polysaccharide complexes: Dissociation of the effects of shearing and heating.

The aim of this study was to dissociate the effect of atomization from that of heating during the spray-drying of Low Methoxyl (LM) pectin/sodium caseinate complexes. The properties of these complexes were studied by measuring turbidity, particle size distribution, zeta-potential, as well as surface hydrophobicity of caseinate within the formed complexes. The results showed that the spraying step had a significant effect on the charge and the size of the complexes. In fact, the application of atomization resulted in the dissociation of caseinate/pectin aggregates especially for high pectin concentrations. Besides, the analysis of the surface hydrophobicity of caseinate indicated that complexation with high concentrations of pectin is able to protect the structure of the protein against heat denaturation. This study allowed a better understanding of the influence of atomization and heat treatment (during the dehydration step) on the molecular interactions within caseinate/pectin complexes.

Modulation of caseinate-stabilized model oil-in-water emulsions with soy lecithin.

Demands for plant-based food and beverage products have escalated in recent years. However, many commercial coffee creamers are still being made using dairy derivatives such as sodium caseinate. Therefore, there is a need to investigate the replacement of dairy based proteins with plant-based alternatives. This study was carried out to systematically investigate the properties of model O/W emulsions stabilized by either sodium caseinate (0.25 to 1.5%) or soy lecithin (0.5 to 1.5%). The model emulsions were made of 10% medium chain triglyceride (MCT) oil-in-water emulsions at pH 7. All model O/W emulsions exhibited whitish appearances similar to that of commercial creamers and were effective at lightening black coffee, except those containing the lowest emulsifier concentrations i.e., 0.25% caseinate or 0.5% lecithin. The lightness of the model emulsions depended on the type and level of emulsifier used, with soy lecithin-stabilized emulsions having similar lightening power compare to that stabilized by sodium caseinate. No feathering or free oil were observed in the whitened coffees at the highest emulsifier level used. Mixtures of caseinate and lecithin emulsifiers were also used and model O/W emulsions with similar physical properties to that stabilized by sodium caseinate alone were produced. The mixed emulsifier-stabilized model emulsions had similar lightness when added to coffee than those stabilized by the individual emulsifiers, suggesting similar stabilization mechanisms using these emulsifiers alone or in combination.

Effect of sodium caseinate and vitamin A complexation on bioaccessibility and bioavailability of vitamin A in Caco-2 cells.

Native sodium caseinate-vitamin A (VA) complexes (Sodium caseinate-VA complex, NaCaS-VA) and modified sodium caseinate-VA complexes i.e. Succinylated sodium caseinate-VA complex (SNaCaS-VA), reassembled sodium caseinate-VA complex (RNaCaS-VA) and reassembled succinylated sodium caseinate-VA complex (RSNaCaS-VA) were prepared and evaluated for their in-vitro bioaccessibility and in-vitro bioavailability of VA through Caco-2 cell lines.VA degraded under acidic conditions as the physiological pH during digestion in stomach was highly acidic (1.2-1.8). During in-vitro gastric digestion, sodium caseinate provided protection to VA, hence, higher VA content was retained in digesta as compared to free VA (oily form). Vitamin uptake by Caco-2 cells was significantly different for digested sodium caseinate-VA complexes as compared to free VA. The peptide content of casein and various sodium caseinate-VA complexes was monitored throughout digestion process. Variation in the complex composition had an effect on protein digestibility and peptide distribution. The bioavailability of VA through sodium caseinate-VA complexes was evaluated by exposing Caco-2 cells to the digesta of milk fortified with various complexes. The total uptake of VA by Caco-2 cells was highest for milk fortified with RSNaCaS-VA followed by RNaCaS-VA, control milk, SNaCaS-VA, NaCaS-VA and free VA. During the formation of RNaCaS-VA and RSNaCaS-VA complexes more hydrophobic sites are exposed, leading to the attachment of VA on the interior hydrophobic regions of sodium caseinate molecule. This led to higher stability of VA during gastrointestinal digestion and further resulted in higher bioaccessibility and bioavailability of vitamin A in Caco-2 cells.

Modified phosphatidylcholine with different alkyl chain length and covalently attached caffeic acid affects the physical and oxidative stability of omega-3 delivery 70% oil-in-water emulsions.

This study investigated the effects of modified phosphatidylcholine (PC) with different alkyl chain lengths (PC_C14 and PC_C16) and covalently attached caffeic acid on the physical and oxidative stability of 70% fish oil-in-water emulsions. High fat emulsions were produced using different amounts of modified PCs in combination with sodium caseinate and soy-PC. Results showed that the physical stability of the emulsions was improved with increasing concentrations of modified PCs, due to their high surface activity. Emulsion stabilized with PC_C14 led to smaller droplets and higher viscosity, whereas PC_C16 had higher protein surface load, which may result in a thicker interfacial layer. Modified PCs enhanced the oxidative stability of the emulsions due to the attachment of caffeic acid to the glycerol backbone of PC, which brings the antioxidant in the vicinity of oil-water interface. PC_C16 led to less formation of primary and secondary oxidation products compared to PC_14 at their equivalent concentrations.

Extraction of orange pectin based on the interaction between sodium caseinate and pectin.

The interaction between commercial orange pectin (COP) and sodium caseinate (SC) was studied using FTIR, fluorescence spectroscopy, CD, and LSCM. The effect of different conditions on the formation and separation of COP-SC complex was determined. The extraction of the orange pectin using SC precipitation (SCOP) was performed, and the physicochemical properties of SCOP were determined and compared with the orange pectin extracted by alcohol precipitation (APOP). The results showed that the electrostatic interaction was the main interaction between these two polymers, and it was strongly dependent on pH, COP/SC ratio, and salt concentration. The mixture of COP and SC formed an electrostatic complex in the pH range of 1.5-6.8 with the absence of NaCl. The recovery rate of SCOP and precipitation rate of SC were 89.43% and 98.33% when the ratio was 1:15. The physicochemical properties of SCOP were almost the same as APOP.

Storage behavior of caseinate-based films incorporating maize germ oil bodies.

Composite films based on sodium caseinate, plasticized with glycerol and incorporating oil bodies recovered by applying ultrafiltration on maize germ aqueous extract were stored at 25 °C and relevant humidity 53% and the changes in their physicochemical and mechanical properties were monitored over a storage period of 2 months. The rearrangement of the protein matrix molecules, oil droplet reorganization and movement during ageing was revealed through the generalized 2D correlation FTIR spectra analysis. Both the control and the oil bodies-containing caseinate films showed marked alterations of their mechanical and optical characteristics upon storage, mainly due to water uptake and glycerol or oil bodies movement, as the application of 2D correlation of the FTIR spectra time series revealed. The fact that the films become less transparent and, in addition, lose and then regain their mechanical strength during ageing for 70 days is essential information for the development of edible films and their commercial applications in the food industry.

Encapsulation of grape seed phenolic-rich extract within W/O/W emulsions stabilized with complexed biopolymers: Evaluation of their stability and release.

The ability of electrostatic complexes made up of sodium caseinate (NaCAS) and a polysaccharide, carboxymethyl cellulose (CMC) or gum Arabic (GA), to retain polyphenols from grape seed extract when encapsulated in W1/O/W2 emulsions was compared to that of the single NaCAS (1%). Both electrostatic complexes (0.5% NaCAS - 0.375% CMC and 0.5% NaCAS - 0.5%GA at pH 5.6) used as hydrophilic emulsifiers in W1/O/W2 were able to stabilize the O/W2 interface for 14 days, even though their protein content was reduced by a 50% regarding that of the emulsions only stabilized with NaCAS. Moreover, interfacial adsorption did not show significant differences between NaCAS-polysaccharide electrostatic complexes and the single NaCAS. In terms of interfacial barrier properties, the rate of polyphenol release during storage was not affected by the type of hydrophilic emulsifier. Since polyphenol transport in W1/O/W2 emulsions was diffusion controlled, interfacial adsorption was considered the main factor limiting polyphenol retention.