Total Biopolymer Concentration Research Articles

Complex coacervate of wheat germ protein/high methoxy pectin in encapsulation of d-limonene

d-limonene is a volatile compound widely used in food flavorings, but it is chemically unstable in the presence of air, light, moisture, and high temperatures. Coacervation is a well-established technique which involves the formation of biopolymer nanocomplexes between negatively charged polysaccharides and positively charged proteins to protect bioactive components. The study shows the effect of pH, protein/polysaccharide ratio and total biopolymer concentration on complex coacervation of defatted wheat germ protein (DWGP) and apple pectin (high methoxyl pectin (HMP)) in the food industry as a carrier and delivery system for d-limonene. DWGP was used for the first time to form coacervate with apple pectin. Turbidity, ζ-potential and particle size of the complex coacervate and their individual biopolymers were examined for preliminary assays of complex coacervation. The optimum condition for DWGP/pectin complex coacervation was found to be at a ratio of 4:1 with a total biopolymer concentration of 1% and a pH of 4.0. The rheological properties of DWGP, pectin, and their coacervate were measured at various pH levels and ratios. The resulting coacervates, used to microencapsulate d-limonene, underwent spray-dried and were characterized using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) measurements. These findings have the potential to contribute to the development of DWGP/pectin complex coacervates as effective delivery systems for volatile aromas or bioactive compounds.Graphical

Interaction and complex formation of sonicated soluble lentil protein and Tremella fuciformis polysaccharide

Proteins’ physicochemical and structural properties critically affect their interactions with polysaccharides. The effect of ultrasound treatment (0–40 min) on the physicochemical properties of soluble lentil proteins (LPs) was investigated. The interaction between LPs (ultrasound-treated for different times, U0-LP, U5-LP, and U40-LP) and Tremella fuciformis polysaccharides (TPS) under different pHs, biopolymer mixing ratios, and total biopolymer concentrations was studied. With the sonication duration increasing, decreased intrinsic fluorescence, higher zeta potential values, and increased hydrophilicity were observed for the sonicated LP samples. The molecule weight of LPs remained unchanged, and their secondary structure changes were independent of the sonication duration. The soluble LPs:TPS complexes and insoluble complex coacervates formed at pH 6.5 (pHc) and pH 6.0 (pHɸ1), respectively, regardless of the mixing ratio and the LP type. The maximum formation of insoluble LPs:TPS complex coacervates (pHopt) occurred at the biopolymer mixing ratio of 4:1 at pH 3.0, 2:1 at pH 3.0, and 2:1 at pH 3.5 for the U0-LP:TPS, U5-LP:TPS, and U40-LP:TPS systems, respectively. The pHɸ1 and pHopt of all the three LPs:TPS systems shifted to higher pH values as the total biopolymer concentration increased. With the greatest dynamic quenching constants (Ksv) and binding site (n) values, U40-LP exhibited the strongest binding affinity with TPS. This was consistent with the highest viscosity of their mixture solution under pHs greater than pHopt. The overall results suggest that ultrasound-treated proteins showed a stronger electrostatic interaction with TPS compared to untreated proteins.

Microencapsulation of curcumin by complex coacervation of lactoferrin and carboxymethyl tara gum for incorporation into edible films

Curcumin is a natural bioactive agent found in turmeric (Curcuma longa) with many health benefits, but with susceptibility to alkaline conditions, light, oxidation and heat. The present research aimed microencapsulate curcumin by complex coacervation using lactoferrin (LF) and carboxymethyl tara gum (CMTG) for application in edible films. The study of wall material formation was carried out by phase diagram, zeta potential and isothermal titration calorimetry. Curcumin was encapsulated by complex coacervation using different core-to-wall ratios and total biopolymer concentration. Finally, the microcapsules were used for the fabrication of edible gelatin-based films. The results showed that LF and CMTG could form complexes at pH 4.5 by electrostatic attraction with high affinity and optimum encapsulation efficiency of curcumin (74.78 %). The microcapsules protected curcumin during the oral and gastric phases with an average release in the intestinal phase of 81.81 %. After in vitro gastrointestinal digestion, the bioaccessibility of encapsulated curcumin was approximately 67 %. Curcumin microcapsules were added to edible gelatin films, which resulted in reduced light transmission and presence of antioxidant activity (FRAP and DPPH·+). The films containing microcapsules had their mechanical properties preserved. Therefore, curcumin-containing microcapsules formed by complex coacervation of LF/CMTG can be used in the production of edible films with high functional properties.

Construction and properties of curdlan gum/gellan gum binary composite gel system

In the present study, the synergetic gelation of curdlan gum (CG) and gellan gum (CG) at different biopolymer ratios were investigated. The optimal gelation of CG and GG was determined at total biopolymer concentration of 0.6% and a mass ratio of 1:1 according to visual observation and viscoelastic properties. The gelation behavior of the CG/GG binary composite gel exhibited ratio-dependent behavior at different biopolymer mixing ratios (2:8–8:2). With the increase in the CG/GG ratio from 2:8 to 8:2, the gel strength and transition temperature of the CG/GG gel showed an increasing trend followed by a decrease, reaching a peak at 5:5, with corresponding G′, melting and gelling temperatures of 335.8 Pa, 82.5 °C and 33.7 °C, respectively. The improved gel properties could be ascribed to hydrogen bonds between CG and GG, as reflected by the blueshift of the O–H vibration peaks and water associated regional variation. Moreover, the CG/GG binary composite gel exhibited a significantly increasing water holding capacity (WHC) as the ratio of CG/GG decreased from 8:2 to 4:6, while the excess involvement of GG had no effect on the WHC improvement. Furthermore, the CG/GG binary composite gel exhibited denser and more homogeneous microstructures in comparison to individual CG and GG and performed the most compact gel network at ratio of 5:5, supporting the stronger gel rigidity and WHC. Therefore, these novel CG/GG hydrogels showed considerable gel strength and microstructures, which would provide a better mechanistic understanding of the polysaccharide complex in practical applications as a hydrogel base material.

High internal phase emulsions and edible films with high methoxyl pectin and pea protein isolate or sodium caseinate

Structuring of sunflower oil by forming HIPEs in the presence of high methoxyl pectin (HMP) and pea protein isolate (PPI) or sodium caseinate (SC) was evaluated first. Initially, emulsions with protein: polysaccharide ratios of 2:1 and 6:1 and two different pectin concentrations (0.5 and 1% wt) were formed and compared with emulsions with just protein, with the former exhibiting greater viscosity and stability. All emulsions exhibited pseudoplastic behaviour with the higher biopolymer concentrations leading to increased emulsion viscosity. The type of protein was significant for stability only for the initial pectin concentration of 0.5% wt. Then, SC and PPI emulsions with a protein: polysaccharide ratio of 6:1 for both pectin concentrations were selected for HIPE formation. The formed HIPE for both proteins had a great oil loss (83–95%), showing that the used combination of biopolymers did not lead to the formation of a structured system. Subsequently, edible films formed by drying the aqueous dispersions of the previously selected protein-polysaccharide binary systems were studied. All films had the same density. The greater total biopolymer concentration led to thicker, heavier, stronger and stiffer films with greater water vapour permeability and opacity. SC films were thicker, heavier, stronger, stiffer and brighter than PPI films, with lower moisture content and opacity. Overall, the used protein affected the studied properties of the films, indicating differences in the formed network.

Phase separation and formation of sodium caseinate/pectin complex coacervates: effects of pH on the complexation

BackgroundThe electrostatic interactions between polysaccharides and proteins are an interesting field in the complex coacervation. PH and mixing ratio have major effect on the complexation and the coacervates structure. Hence, it is necessary to find the optimum pH and mixing ratio of the coacervates as well as understanding the thermal, mechanical, and structural characterization of the coacervates. Thus, structural changes of the complexes of sodium caseinate (NaCas) and high methoxyl pectin as a function of pH (2.00–7.00), biopolymer ratios (1:1, 2:1, 4:1, and 8:1), and total biopolymer concentration (0.1, 0.2, and 0.4% w/v) were evaluated by light scattering and ζ-potential measurements. The phase separation behavior of the NaCas/HMP coacervate and its kinetics turbidity were also investigated via monitoring the turbidity profiles. Moreover, the thermal, rheological and structural behavior of the coacervates was evaluated at the selected pH values.ResultsThe highest turbidity, particle size, and viscosity were achieved at pHmax = 3.30 and formation or dissociation around the pHmax was confirmed by particle size and FTIR. The optimum condition for the coacervation of NaCas and HMP was obtained at ratio 4:1 and 0.4% w/v. Thermal and mechanical stability of the NaCas/HMP coacervates was improved at pH 3.30. By increasing the total concentration of biopolymers, the NaCas/pectin ratio shifted to higher pH values. Furthermore, the maximum coacervate yield was achieved at 39.8% w/w at a ratio of 4:1 of NaCas/HMP and a total biopolymer concentration of 0.4% w/v.ConclusionPhase separation behavior of the coacervates exhibited the optimum pH in coacervation between NaCas and HMP. Furthermore, the rheological, thermal and structural stability of the coacervates were improved in comparison with the single biopolymers.Graphical

Unraveling the phase behavior of cricket protein isolate and alginate in aqueous solution

The associative phase behavior of cricket protein isolate (CPI) and sodium alginate (AL) in aqueous solutions was explored using turbidimetry, methylene blue spectroscopy, zeta potentiometry, dynamic light scattering, and confocal microscopy as a function of pH, biopolymer ratio, total biopolymer concentration (CT), and ionic strength. When both biopolymers had net-negative charges, soluble complexes formed between pH 6.0 and 8.0, however when both biopolymers had opposing net charges, insoluble complexes formed as complex coacervates below pH 5.5, defined as pHφ1, followed by precipitates below another critical pH 3.0 (pHp). Increasing the CPI:AL weight ratio or CT facilitated complex formation, and the addition of salts (NaCl/KCl) had a salt-enhancement and salt-reduction impact at low and high salt concentrations, respectively. Ionic interactions between oppositely charged CPI and AL were mainly responsible for the formation of their insoluble complexes, while hydrogen bonding and hydrophobic interactions also played significant roles.

Formation and stability of electrostatic complexes formed between scallop female gonad protein isolates and sodium alginate: Influence of pH, total concentration, blend ratio, and ionic strength.

The complex coacervation between scallop (Patinopecten yessoensis) female gonad protein isolates (SFGPIs) and sodium alginate (SA) was determined by the turbidimetric method. The impact of pH, total biopolymer concentration, biopolymer blend ratio, and various salt ionic on the mechanisms governing the complex coacervation of SFGPIs-SA complexes were also investigated. For the SFGPIs:SA ratio of 2:1 without adding NaCl, insoluble and soluble complexes were observed at pH 5.8 (pHφ1 ) and pH 8.2 (pHc ) with the optimum biopolymer interactions appearing at pH 2.6 (pHopt ). The maximum turbidity value increased with the increment of the total biopolymer concentration from 0.37 to 1.83 until attaining the critical value (0.75%). As the blend ratios rose from 1:3 to 12:1, the critical pH values (pHc , pHφ1 , and pHopt ) moved to higher pH. Furthermore, the addition of NaCl led to a remarkable decrease in turbidity over the whole pH region in SFGPIs-SA complexes. Moreover, monovalent ions (Na+ and K+ ) had the same effect on the formation of the SFGPIs-SA complex, whereas the divalent cations (Mg2+ and Ca2+ ) lessened the complex formation in comparison with the monovalent ions. This study offers a methodological and theoretical basis for the design of complex SFGPIs-SA systems by understanding the complex coacervation under different conditions. PRACTICAL APPLICATION: In recent years, several protein-polysaccharides complexes have been widely applied in food and biological systems. Scallop (Patinopecten yessoensis) female gonads are deemed as good marine sources for developing protein matrices on account of their high protein content and nutrients. In our study, the effects of different conditions on the mechanisms governing the complex coacervation of SFGPI-SA mixtures were investigated, and the instability of the system could be overcome by understanding the conditions for SFGPIs/SA complex formation, which have a feasible role in developing marine source-protein as afunctional food base such as kamaboko gels, can, sausage, fat substitutes, and delivery vehicles for bioactive compounds.

Complex Coacervation and Precipitation Between Soluble Pea Proteins and Apple Pectin

Complex formation (leading to either coacervation or precipitation) offers a tool to generate plant-based novel food structures and textures. This study investigated the formation of complexes between soluble pea proteins and apple pectin upon varying the protein-to-pectin ratio (r = 2:1 to 10:1), pH (3–7), and temperature (25 and 85 °C) with a total biopolymer concentration set to 1% (w/w). The results showed that predominantly soluble biopolymer complexes were formed at pH 5, and at low ratio (r = 2:1), whereas lowering the pH to more acidic condition, and to higher ratios (r = 4:1–10:1) induced the formation of more insoluble biopolymer complexes. In general, the mean particle sizes of the biopolymer complexes ranged between approximately 20 and 100 μm. Upon heating to 85 °C, the amount of insoluble biopolymer complexes increased at pH 3–5 at all ratios, except at r = 2:1. In addition, the complex sizes became somewhat larger at r = 2:1 to 6:1 upon heat treatment, whereas only trivial size changes were observed at higher ratios (r = 8:1 to 10:1). Overall, electrostatic and hydrophobic interactions played a major role in the complex formation between the soluble pea proteins and apple pectin. These findings are important for designing solely plant-based food structures.

Physicochemical and mechanical properties of a new cold-set emulsion gel system and the effect of quinoa protein fortification

A new approach for soft and self-sustainable oil-in-water emulsion gel systems (EGs) preparation based on a formulation with olive oil, sodium alginate, citric acid, and calcium chloride, and the combination of high-speed homogenization and gelation induction by glucono-δ-lactone addition is presented. Also, the effect of EG protein fortification by the incorporation of quinoa concentrate (QC) and quinoa flour on the physicochemical and mechanical properties of these EGs upon storage at 4 °C was investigated. Despite soft and self-sustainable EGs (10 g/kg and 20 g/kg alginate, respectively) showed higher oil droplet size increment with total biopolymer concentration, these systems presented remarkable stability during 28 days. All fortified EGs showed higher fluid retention capacity (>99%), L*, a*, and lower b* values. After one day, EGs presented pHs ranging 4.1–4.3, and longer storage times promoted an increased acidity, to a less extent for QC-fortified-EGs. Lipid oxidation degree also increased during storage (from 30 to 150 μmol/L malonaldehyde), with no significant effects upon protein fortification. Protein fortification promoted higher gel strength in all self-sustainable EGs (from 3.5 N to almost 7 N), and especially after 14 days for soft-EGs. These EGs can be used in the food industry as fat replacers to formulate healthier products.

Complexation of nanofibrillated egg white protein and low methoxy pectin improves microstructure, stability, and rheology of oil-in-water emulsions

Structured emulsions (40–70% oil) were designed through complexation between nanofibrillated egg white protein (FEWP) and pectin and emulsion properties were then evaluated at different pHs and biopolymer concentrations. While native egg white protein (NEWP) and pectin formed insoluble complexes, TEM observation the FEWP and pectin complexes consisted of unpacked supramolecular network. The rheological properties of these protein-pectin complexes were significantly influenced by pH, protein-to-pectin ratio, and biopolymer concentration. While pectin addition had no significant influence on the rheological properties of emulsions made by NEWP at oil contents between 40 and 50%, pectin significantly improved the viscosity and elastic modulus of the emulsions prepared by FEWP. This effect was optimized at a protein-to-pectin ratio of 10:1 and pH 3.7. Furthermore, the elastic module was enhanced for the FEWP/pectin complex (FEWP/P) emulsions by increasing the total biopolymer concentration. The capability of FEWP-pectin complexes to make emulsions with enhanced elastic modulus and stability could be ascribed to the fibrillar structure of nanofibrils, enabling them to create a solid network at the continuous phase of the emulsions by complexation with pectin. This study demonstrates the potential of nanofibrillar EWP/pectin complexes for fabricating structured O/W emulsions at reduced fat content. This may contribute to formulations for healthier emulsion-based food products with an improved texture such as sauces, mayonnaises, dressings, and dips.

Preparation and characterization of soybean Protein isolate/chitosan/sodium alginate ternary complex coacervate phase

To improve morphological structure and stability of soy protein isolate - chitosan coacervate, a soy protein isolate-chitosan-sodium alginate ternary complex coacervate phase was successfully constructed by adding sodium alginate. The ζ -potential and turbidity data showed that soy protein isolate, sodium alginate, and chitosan interacted with each other in the pH range 5.0–7.0. The highest ternary coacervate yield was obtained at soy protein isolate/sodium alginate ratio 12:1 (g/g), soy protein isolate/sodium alginate:chitosan ratio 4:1 (g/g), pH 6.5, and total biopolymer concentration of 5 g/L. The viscoelastic properties and microstructure were also studied using rheology, fourier transform infrared spectroscopy, texture profile analysis, and scanning electron microscopy, which indicated that the ternary coacervates prepared in pH 5.5, 6.0, and 6.5 had a viscoelastic solid behavior (storage moduli between 12,600 and 35,000 Pa; loss moduli between 3440 and 10,000 Pa) with honeycomb porous network structures. The ternary coacervate prepared at pH 6.5 was more compact and clearly porous. The stability of the ternary complex coacervate phase to pH and ionic strength slight increased. The in situ cross-linking of sodium alginate can improve the structure properties of ternary coacervates, which may provide a new carrier to incoporate bioactive ingredients into food products.

Formulation, spray-drying and physicochemical characterization of functional powders loaded with chia seed oil and prepared by complex coacervation

In this research, complex coacervation between soy protein isolate (SPI) and gum arabic (GA) constituted a preliminary step for developing chia oil (CO)-in-water emulsions suitable for subsequent spray-drying. The contributions of total biopolymer concentration, SPI-GA ratio w/w and ionic strength on coacervate yield (CY) were quantified through a 3×6×4 factorial design. The SPI-GA ratios that gave the highest CY values (1-1 and 2-1) were selected to prepare emulsions and blank dispersions (devoid of CO). The preparation process included four well-defined sequential steps: high speed homogenization, high pressure homogenization, complex coacervation and a carrier addition (maltodextrin). The emulsification step, the SPI-GA ratio and the presence of CO had a significant effect (p ≤ 0.05) on ζ-Potential, apparent viscosity, structural recovery of the systems, gel strength and cross-linking. The microencapsulation process preserved the quality of CO (2.18 ± 0.01 h), as reflected by enhanced oxidative stability indices (around three times higher than bulk CO, 5.65–6.84 h) and non-significant changes in α-Linolenic acid after spray-drying and in-vitro digestion processes (60–66.53%, relative abundance). In addition, thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) helped corroborate the stability of CO within the powders' structure. Finally, different characteristics of powders were significantly influenced (p ≤ 0.05) by the presence of CO, especially the color, flowability and sorption-dependent properties: the monolayer content (Wm) and the bulk moisture diffusivity.

Co-encapsulation of L-ascorbic acid and quercetin by gelatin/sodium carboxymethyl cellulose coacervates using different interlayer oils

A two-step emulsification prior to complex coacervation was employed to develop a co-encapsulation technology of hydrophilic and hydrophobic components for nutrition enhancement. Processing parameters of mononuclear ellipse-like microcapsules using gelatin and sodium carboxymethyl cellulose as wall materials were evaluated. The particle size and morphology of microcapsules and the encapsulation efficiency of L-ascorbic acid were significantly affected by the water–oil phase ratio and total biopolymer concentration. The L-ascorbic acid and quercetin co-encapsulated microcapsules with an average size of 65.26 µm showed good physical and chemical stability. The encapsulation efficiencies of L-ascorbic acid and quercetin were 69.91% and 88.21%, respectively. To predict the potential of functional lipids as hydrophobic carriers, microcapsules using soybean oil, olive oil, fish oil, and conjugated linoleic acid as interlayer oils were developed. The encapsulation efficiencies of hydrophobic compounds carried by different oils were similarly high (88.21–93.08%), whereas, hydrophilic ones carried by conjugated linoleic acid had the lowest encapsulation efficiency (32.54%). The interface tension results indicated that the interfacial stability was impaired by a competitive relation between conjugated linoleic acid and hydrophobic emulsifier at the interface, due to their structural similarity. These results provided the guidance for improving the quality of interlayer oils from microcapsules.

Formulation and additive manufacturing of polysaccharide-surfactant hybrid gels as gelatin analogues in food applications

A vegetarian alternative to gelatin, for use in food applications was proposed as a synergistic combination of 0–2 wt% low acyl gellan gum (LAG) and 0–2 wt% tamarind seed xyloglucan (TSX). The mechanical, thermal and temperature-mediated release properties of the gels were examined using rheology and conductivity. The influence of the addition of a food grade emulsifier, Tween® 20, was also investigated. It was found that both the total concentration of biopolymers and the ratio of polymer blends influenced thermal (gelling and melting temperatures) and mechanical (storage modulus and phase angle) properties, however the total polymer concentration was the major factor. The addition of Tween® 20 led to small increases gelling and melting temperatures, elastic modulus and a small reduction phase angle in most of the LAG/TSX samples. Using rheological data the LAG/TSX samples were predicted to be printable using extrusion-based additive manufacturing, which was then performed on a custom-made printer. The rheological and release data suggested that 0.5 wt% LAG/1.5 wt% TSX/1 wt% Tween® 20 was the most similar to a tested sample of 5 wt% porcine gelatin in terms of viscoelastic moduli, gelling & melting temperatures and release profile, and could therefore be developed as a printable gelatin replacement. No difference was found between the release properties of moulded versus printed gels.

Microencapsulation of Sacha Inchi Oil by Complex Coacervates using Ovalbumin-Tannic Acid and Pectin as Wall Materials

The objective of this work was to microencapsulate sacha inchi oil (SIO) by the complex coacervation technique using ovalbumin (OVA), tannic acid (TA) and pectin (PEC) as wall materials. The interaction between the biopolymers, the encapsulation efficiency (EE%) and the structural and thermal characteristics of the formed microcapsules were confirmed. In addition, the presence of phenolic compounds (TA) in the wall material increased the nutritional value of the microcapsules. In the process of microcapsule formation by complex coacervation, a pH value of 3.5 and an OVA:PEC ratio of 4:1 led to a high turbidity and a strong interaction between the biopolymers. The interaction between OVA-TA was confirmed and added value to the OVA and PEC complex. The EE% found was between 70 and 80%, with an ideal proportion and total concentration of biopolymers of 2: 1 (OVA-TA: PEC) and 2.0%, respectively. As demonstrated using the complex coacervation technique, the microcapsules showed high thermal stability and excellent encapsulating capacity without changing the chemical composition of SIO.

Microencapsulation of vitamin D3 by complex coacervation using carboxymethyl tara gum (Caesalpinia spinosa) and gelatin A

Vitamin D3 plays a fundamental role in human health; however, it is highly susceptible to environmental conditions and the gastrointestinal tract. In this study, complex coacervates obtained from gelatin A and carboxymethyl tara gum (CMTG) were used as wall materials for the encapsulation of vitamin D3 (VD3). Zeta potential and turbidity measurements were employed to optimize the pH and ratio (gelatin A:CMTG), and the results showed that the ideal conditions for the complex coacervation were pH 4.0 and a 6:1 ratio. The encapsulation efficiency (EE) was determined as a function of the total concentration of biopolymers (TC%) and the core-to-wall ratio, and the greatest EE (80%) was achieved at a TC of 1% and a ratio of 1:2; spherical particles with an average size of 0.25 µm were obtained. The microencapsulation increased the thermal stability of VD3, and FTIR confirmed the presence of the biopolymers and VD3 in the capsules. An in vitro simulation showed a more pronounced release in the small intestine with a vitamin bioaccessibility of 56%. The encapsulation of bioactive lipophilic compounds by complex coacervates of gelatin A and CMTG resulted in improved stability and prolonged release during digestion.

Carboxymethyl tara gum-lactoferrin complex coacervates as carriers for vitamin D3: Encapsulation and controlled release

In this study, a controlled release system of coacervated complexes consisting of lactoferrin (LF) and carboxymethyl tara gum (CMTG) was developed. Zeta potential and turbidity measurements were employed to optimize pH and the LF:CMTG ratio, and the results showed that pH 4.0 and a 5:1 ratio (LF:CMTG) were ideal for complex formation. These conditions promoted the encapsulation of vitamin D3, and the encapsulation efficiency (EE) was determined to be a function of the total concentration of biopolymers (TC%) and the core-to-wall ratio. The results showed that the highest EE (81%) was achieved for a TC of 1% and a ratio of 1:3. The particles had a spherical shape and an average size of 1.2 μm, which was influenced by the TC%. The thermal stability of the vitamin increased after microencapsulation, and Fourier transform infrared spectroscopy (FTIR) demonstrated the presence of biopolymers and vitamins in the microcapsules. The results of the in vitro simulation showed that the microcapsules enabled the vitamin to be released in the intestine with 35% bioaccessibility. Encapsulation of lipophilic bioactive compounds, such as vitamin D3, was achieved through complexes formed between LF and CMTG, which improved the stability and promoted the controlled release of the vitamin during gastrointestinal simulation in vitro.

A deeper insight into the characteristics of double-layer oil-in-water emulsions stabilized by Persian gum and whey protein isolate

Whey protein isolate (WPI) is an excellent emulsifier. However, WPI-stabilized emulsions tend to flocculate at pH values close to their isoelectric point. In this work, a layer by layer (LBL) technique was used to develop double layer oil in water emulsions using a mixture of WPI and water-soluble fraction of Persian gum (WSPG). Polysaccharide concentration and pH were found to have a major impact on the stability of the final system. At a constant total biopolymer concentration, increasing the amount of WSPG significantly (p < 0.05) improved the emulsion physical stability. An appropriate stability was obtained at 0.5 wt% WPI, 1 wt% WSPG, and pH 5.0. At high ionic strength, the emulsions became unstable with a higher sensitivity to CaCl2 than NaCl. Confocal laser scanning microscopy and zeta-potential measurements confirmed the electrostatic adsorption of WSPG onto the WPI-stabilized oil droplets. The results of interfacial tension and dilatational rheology measurements revealed a slight decrease in the interfacial tension after the adsorption of WSPG as the second layer and a predominantly elastic behavior (E′ > E″), at the interface especially at pH 5.0. The results showed that WSPG is an appropriate candidate for improving the physical stability of WPI-stabilized emulsions at pH values close to isoelectric point.

Design of pH-Induced complex coacervates of gelatin and wattle

Complex coacervation of two naturally occurring polymers is crucial in design of wall materials, particularly in the food and related industry. This work presents an analysis of the complex coacervate yield of two oppositely charged polymers, viz., gelatin and wattle varying parameters like pH, polymeric mass ratio, and total biopolymer concentration through zeta potential and turbidity measurements. Results show that for the boundary conditions employed in the study, maximum coacervate yield (65 ± 0.9 %) was for wattle:gelatin ratio of 2:1, pH 4.2. At 2.2 ± 0.1 g of wattle/ g of gelatin, large micron-sized aggregates with polydispersity index of 1 have been obtained. Turbidity of the dispersion is inversely proportional to coacervate yield and has been optimized at a total biopolymer concentration of 3% at a wattle to gelatin mass ratio of 2 for applications.