Whey Protein Isolate Concentration Research Articles

Gelation properties and swallowing characteristics of heat-induced whey protein isolate/chia seed gum composite gels as dysphagia food

Soft gels based on protein-polysaccharide composite systems play a crucial role in the dietary management of people with dysphagia. The effect of chia seed gum (CSG) on the gelling and swallowing properties of heat-induced whey protein isolate (WPI) gels (3.125–75 mg/mL) was investigated. The results showed that adding CSG reduced the gelation concentration of WPI and weak gels could form at 12.5 mg/mL WPI concentration. In addition, the viscoelasticity and water-binding capacity of the WPI/CSG composite gels were gradually enhanced with increasing WPI concentrations. The WPI/CSG composite systems can be classified as level 2–5 dysphagia-oriented foods according to the International Dysphagia Diet Standardization Initiative (IDDSI) framework. The incorporation of CSG promoted the cross-linking of protein aggregates and the formation of compact and continuous network structures, resulting in improved gelling properties of composite systems. This study contributes to the development of novel soft gel-type dysphagia foods with better textural characteristics.

Enhancing the insecticidal efficacy of Allium sativum extracts through microencapsulation via complex coacervation

Garlic (Allium sativum L.) has been widely studied for its insecticidal properties. The primary bioactive molecule in garlic extracts include allicin, alliin, S-allylcysteine, diallyl disulfide, diallyl trisulfide, diallyl sulfide and ajoene. However, these compounds degrade under environmental conditions once extracted. This study aimed to enhance the effectiveness of garlic extracts in controlling Tenebrio molitor by optimizing microencapsulation techniques. The garlic extracts were encapsulated using the complex coacervation method, with independent variables including pH levels (3, 6 and 9), whey protein isolate (WPI) (4 %, 6 % and 8 % w/v) and pectin (0.50 %, 0.75 % and 1.00 % w/v). A Taguchi L9 (33) orthogonal array was employed to design 9 treatments, and T. molitor mortality was assessed 72 h after a 10 sec immersion of the insects in the treatments. Statistical analysis revealed that WPI had the most significant influence (24.52 %), followed by pH (18.82 %) and pectin (7.79 %). The interaction between pH and pectin had the greatest effect on the encapsulation process, accounting for 38.65 % of the influence. The optimal microencapsulation conditions were predicted by software to be pH 3, a pectin concentration of 0.75 % w/v and a WPI concentration of 4.00 % w/v, resulting in a signal-to-noise (S/N) ratio of 42.30. Experimental validation of these conditions produced an S/N ratio of 18.54, corresponding to a T. molitor mortality rate of 92 % ± 4.47 %. The resulting microcapsules had diameters ranging from 1–5 ?m. Complex coacervation is a highly promising method for microencapsulating garlic extracts and preserving their insecticidal properties.

Effect of whey protein on the formation, structure and gastrointestinal breakdown of quinoa flour-based composite gels

Whole grain flour has captured increasing attention due to its health benefits. Herein, the quinoa flour-based composite gels were fabricated by heating quinoa flour dispersions containing 0-7 w/w% whey protein isolate (WPI). The thermal properties and gel formation of the dispersions were determined, along with the large deformation and fracture properties, microstructure, and molecular reorganization of the resulting gels. Protein hydrolysis, solid loss, glucose release and microstructural changes were monitored to characterize the gastrointestinal breakdown of the gels. Results showed that quinoa starch was gelatinized at 60-70 °C. Upon heating, quinoa starch was segregated into microparticles of ∼ 3 μm, which aggregated into the starch phase, whereas protein aggregates filled the gap of the starch gel network. A bicontinuous structure was formed with increasing WPI concentration to 7 w/w%. Meanwhile, the storage modulus, gel hardness and fracture stress of the gels increased by 5-8 times. The addition of WPI inhibited gel disintegration during in vitro digestion. However, intestinal glucose release was not delayed because of the phase-separated structure of the gels. With increasing WPI concentration, larger protein aggregates survived after 5 min of intestinal digestion, demonstrating that the enhanced protein network was the main contributor slowing down gel disintegration during in vitro digestion. This work would promote the development of quinoa flour-based products with controlled digestion.

3D Printing Properties of Heat-Induced Sodium Alginate-Whey Protein Isolate Edible Gel.

The objective of this study was to develop a food 3D printing gel and investigate the effects of whey protein isolate (WPI), sodium alginate (SA), and water-bath heating time on the 3D printing performance of the gel. Initially, the influence of these three factors on the rheological properties of the gel was examined to determine the suitable formulation ranges for 3D printing. Subsequently, the formulation was optimized using response surface methodology, and texture analysis, scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy were conducted. The rheological results indicated that gels with WPI concentrations of 6-7 g, SA concentrations of 0.8-1.2 g, and water-bath heating times of 10-12 min exhibited lower yield stress and better self-supporting properties. The optimized formulation, determined through response surface methodology, consisted of 1.2 g SA, 6.5 g WPI, and a heating time of 12 min. This optimized formulation demonstrated enhanced extrusion capability and superior printing performance. SEM analysis revealed that the optimized gel possessed good mechanical strength, and FTIR spectroscopy confirmed the successful composite formation of the gel. Overall, the results indicate that the optimized gel formulation can be successfully printed and exhibits excellent 3D printing performance.

Effects of whey proteins and erythritol combination on the physical and quality characteristics of untempered, high-protein white chocolates without the saccharose addition

This study aimed to assess impact erythritol and whey protein isolate (WPI) impact on the physical characteristics of untempered, high-protein (12/16/20/24% (w/w) of protein) white chocolates without the saccharose addition. Surfacial properties were analysed from colour coordinates, advancing and receding contact angles, apparent surface free energy and roughness. Rheological and mechanical properties, melting characteristics and water activity were also determined. Larger WPI additions facilitated greater hydrophobicity in the samples and demonstrated a smoothing effect. The mechanical characteristics, resistance to melting and shelf life were enhanced by the higher whey protein addition; however, the colour parameters were slightly affected. The samples with the higher WPI concentrations produced a continuous, more densely packed and three-dimensional solid network as visualized by the confocal microscopy, which showed the variations in their microstructures. Both compounds demonstrated an anti-blooming effect that allowed to skip tempering, reduce manufacturing costs and improve nutritional quality of resulting white chocolates.

Improving salidroside stability using water-in-oil-in-water emulsion with whey protein isolate: Formation and characterization

A water-in-oil-in-water (W/O/W) emulsion for the encapsulation of salidroside (Sal) was constructed. This study aimed to detect the impact of whey protein isolate (WPI) on the microstructure and stability of Sal W/O/W emulsion, which was prepared by two-step emulsification. First, Sal and sodium alginate (SA) were added to the inner water phase, and polyglycerol polyricinoleate (PGPR) was added to the oil phase to prepare a water-in-oil (W/O) emulsion. Second, different concentrations of WPI were added to the outer water phase containing SA to prepare a Sal W/O/W emulsion. The microstructure, stability, moisture distribution, rheological properties, and encapsulation efficiency of Sal were detected. The results showed that the particle size and the size distribution range became smaller and narrower with increasing WPI concentration. When the concentration of WPI was greater than 2%, the double-layer structure remained stable over 28 days of storage at 4 °C. Moreover, when the WPI concentration reached 4%, the entrapment efficiency of Sal was the highest. These results indicated that the optimum concentration of WPI was 4%.

Grafted calcium pectinate-whey protein isolate covalent immobilizers: Optimization, kinetics, thermodynamics, and application

Whey protein isolate (WPI) was incorporated within calcium pectinate (CPT) beads in order to boost their anionic qualities and meliorate their glutaraldehyde (GA)-polyethyleneimine (PEI) grafting process. The Box-Behnken Design (BBD) verified that WPI inclusion significantly raised the GA-PEI-CPT-WPI beads immobilized β-D-galactosidase (iβ-GLD) activity. The BBD also revealed the optimal settings for WPI concentration, PEI pH, PEI concentration, and GA concentration, which were 2.91 %, 10.8, 3.5 %, and 2.24 %, respectively. The GA-PEI-CPT-WPI beads grafting process was scrutinized via FTIR, EDX, and SEM. The optimal GA-PEI-CPT-WPI immobilizers provided fine β-GLD immobilization efficiencies, which reached up to 65.28 %. The free and GA-PEI-CPT-WPI iβ-GLDs pH and temperature profiles were scrutinized. It was also unveiled that the thermal stability of the iβ-GLD surpassed that of its free compeer as it provided lesser kd and ΔS values and larger t1/2, D-values, Ed, ΔH, and ΔG values. Furthermore, the iβ-GLD provided 92.00±3.39 % activity after 42 storage days, which denoted its fine storage stability. The iβ-GLD short duration (15 min) operational stability was also inspected, and 82.70±0.78 % activity was provided during the fifteenth degradation run. Moreover, the iβ-GLD long duration (24 h) operational stability was inspected while degrading the lactose of buffered lactose solution (BLS) and cheese whey (CW). It was unveiled that 81.86±0.96 % and 73.58±2.24 % of the initial glucose were detected during the sixth degradation runs, respectively.

Whey protein isolate-stabilized gardenia fruit oil nanoemulsions: Ultrasonic preparation, characterization and applications in nutraceuticals delivery

In the current research, ultrasound was applied to make whey protein isolate (WPI)-gardenia fruit oil nanoemulsion. Effects of preparation conditions on physicochemical characteristics of nanoemulsions were investigated. The smallest droplet size was obtained at the oil content of 10% (v/v) and the WPI concentration of 0.5% (w/v) with ultrasound (2.4 W/mL, 12 min). Ultrasound led to a more uniform nanoemulsion with smaller droplet sizes (< 300 nm). The nanoemulsion prepared with ultrasound remained relatively stable for more than one week, while the crude emulsion prepared without ultrasound layered after 1 day storage. The nanoemulsion was more stable at lower temperature, alkaline condition and lower Na+ concentration. The formation of nanoemulsions significantly reduced the generation rate and amount of POV and TBARS during the 14-day accelerated oxidation experiment, increasing the oxidation stability of gardenia fruit oil. Additionally, the nanoemulsion could encapsulate β-carotene, hesperetin and naringenin at the efficiency of 79.61%, 51.29% and 46.06%, which further improved the oil oxidation stability and retarded free fatty acids release during the stimulated digestion in vitro.

Combination of Machine Learning and Raman Spectroscopy for Determination of the Complex of Whey Protein Isolate with Hyaluronic Acid.

Macromolecules and their complexes remain interesting topics in various fields, such as targeted drug delivery and tissue regeneration. The complex chemical structure of such substances can be studied with a combination of Raman spectroscopy and machine learning. The complex of whey protein isolate (WPI) and hyaluronic acid (HA) is beneficial in terms of drug delivery. It provides HA properties with the stability obtained from WPI. However, differences between WPI-HA and WPI solutions can be difficult to detect by Raman spectroscopy. Especially when the low HA (0.1, 0.25, 0.5% w/v) and the constant WPI (5% w/v) concentrations are used. Before applying the machine learning techniques, all the collected data were divided into training and test sets in a ratio of 3:1. The performances of two ensemble methods, random forest (RF) and gradient boosting (GB), were evaluated on the Raman data, depending on the type of problem (regression or classification). The impact of noise reduction using principal component analysis (PCA) on the performance of the two machine learning methods was assessed. This procedure allowed us to reduce the number of features while retaining 95% of the explained variance in the data. Another application of these machine learning methods was to identify the WPI Raman bands that changed the most with the addition of HA. Both the RF and GB could provide feature importance data that could be plotted in conjunction with the actual Raman spectra of the samples. The results show that the addition of HA to WPI led to changes mainly around 1003 cm-1 (correspond to ring breath of phenylalanine) and 1400 cm-1, as demonstrated by the regression and classification models. For selected Raman bands, where the feature importance was greater than 1%, a direct evaluation of the effect of the amount of HA on the Raman intensities was performed but was found not to be informative. Thus, applying the RF or GB estimators to the Raman data with feature importance evaluation could detect and highlight small differences in the spectra of substances that arose from changes in the chemical structure; using PCA to filter out noise in the Raman data could improve the performance of both the RF and GB. The demonstrated results will make it possible to analyze changes in chemical bonds during various processes, for example, conjugation, to study complex mixtures of substances, even with small additions of the components of interest.

Improvement of phycocyanin stability at different temperatures using microencapsulation by whey protein isolate

Phycocyanin is a blue pigment in cyanobacteria known for its antioxidant activity and can be applied as a natural food colorant. However, one drawback to applying phycocyanin in food products is their high-temperature instability. In this research, we investigated the effect of encapsulation of phycocyanin using whey protein isolate (WPI) as the wall material to improve high-temperature stability. The study also assessed the physiochemical properties of microencapsulated phycocyanin. Phycocyanin was extracted from dry biomass Spirulina using a cold maceration method. Then, phycocyanin extract was encapsulated with prepared emulsions containing 0.25%, 0.50%, 0.75%, and 1.00% WPI as wall materials. The result showed all microencapsulated phycocyanin, regarding various concentrations of WPI, showed lower phycocyanin degradation at 60°C and 70°C at various heating times compared to control, suggesting higher stability. The control sample had 35.55±0.33% and 62.61±0.55% concentration degradation at 60°C and 70°C after 10 min heating. The microencapsulated phycocyanin with 0.50% WPI had 12.67±2.08% and 19.95±2.02% at 60°C and 70°C after 10 min heating. The encapsulation efficiency achieved 98-99% regarding various concentrations of WPI. There was no significant difference in solubility between the control and microencapsulated phycocyanin. Our result concluded that microencapsulation, using WPI as wall material, improved the high-temperature stability of phycocyanin.

Development of hen egg-based protein beverages with high nutritional value.

Physical stability is a prerequisite for any emulsion-based beverage. This study aimed to optimize beverage emulsion (BE) rich in whole egg, whey protein isolate (WPI), and soyabean oil in the presence of polygalactose derivative as adsorbing hydrocolloids (AH) and partially hydrolyzed starch as non-adsorbing hydrocolloids (NAH). All formulations were optimized for stability, particle size, polydispersity index (PDI), and zeta potential (ζ). A central composite design was applied to investigate the impact of WPI concentration, hydrocolloid concentration, oil volume, and pH as independent factors on particle size, PDI, and ζ of emulsions. The optimum conditions were met upon formulating BE with 1 whole egg, 9.28g WPI, 11.24g AH, 5.58mL oil at pH 7. Two optimal formulations were obtained for BE stabilized with NAH at pH 3 and 7, at which droplets had the highest electrical charge. Noting that, less amount of NAH (7.5g) was required at pH 3 than at pH 7 (13.56g). Oil content (3mL) and WPI concentration (16g) for both NAH formulations were similar. The size, polydispersity index (PDI), and zeta potential of AH-stabilized emulsion were 762nm, 0.69, and - 32.05mV, respectively, while for NAH emulsion, they were 150.02nm, 0.40, and - 28.53mV at pH 7; and 248.39nm, 0.41, and 27.1mV at pH 3, respectively. No conspicuous gravitational separation was observed after 20days of storage at 4°C. Hence, both hydrocolloids are appropriate to stabilize protein-enriched BE at neutral pH; however, physical stability was also achieved at acidic pH for NAH-stabilized emulsions.

WPI-coated liposomes as a delivery vehicle for enhancing the thermal stability and antioxidant activity of luteolin

The practical application of luteolin in food systems faces challenges due to its inherent instability. This study aimed to develop luteolin-loaded liposomes coated with whey protein isolate (WPI) to enhance the thermal stability and antioxidant activity of luteolin. The physical characteristics of both luteolin-loaded liposomes (LUT-Lips) and WPI-coated luteolin-loaded liposomes (WPI-LUT-Lips) were assessed. At a 5% WPI concentration, WPI-LUT-Lips demonstrated excellent dispersibility and improved encapsulation efficiency. WPI interacted with the liposome membrane via hydrophobic forces, hydrogen bonding, and electrostatic contact force, resulting in an efficient coating. Differential scanning calorimetry confirmed that WPI-LUT-Lips exhibited greater thermal stability compared to LUT-Lips, attributed to the protective effect of the WPI. Furthermore, WPI-LUT-Lips displayed superior antioxidant activity, as evidenced by their DPPH scavenging activity (86.36 ± 1.95%), TBARS reduction (25.33 ± 1.90%), and reducing power (82.86 ± 1.42%). Therefore, WPI-coated luteolin-loaded liposomes offer a promising way to enhance luteolin’s integration into food systems.

Endothelialization of Whey Protein Isolate-Based Scaffolds for Tissue Regeneration.

Whey protein isolate (WPI) is a by-product from the dairy industry, whose main component is β-lactoglobulin. Upon heating, WPI forms a hydrogel which can both support controlled drug delivery and enhance the proliferation and osteogenic differentiation of bone-forming cells. This study makes a novel contribution by evaluating the ability of WPI hydrogels to support the growth of endothelial cells, which are essential for vascularization, which in turn is a pre-requisite for bone regeneration. In this study, the proliferation and antioxidant levels in human umbilical vascular endothelial cells (HUVECs) cultured with WPI supplementation were evaluated using real-time cell analysis and flow cytometry. Further, the attachment and growth of HUVECs seeded on WPI-based hydrogels with different concentrations of WPI (15%, 20%, 30%, 40%) were investigated. Supplementation with WPI did not affect the viability or proliferation of HUVECs monitored with real-time cell analysis. At the highest used concentration of WPI (500 µg/mL), a slight induction of ROS production in HUVECs was detected as compared with control samples, but it was not accompanied by alterations in cellular thiol levels. Regarding WPI-based hydrogels, HUVEC adhered and spread on all samples, showing good metabolic activity. Notably, cell number was highest on samples containing 20% and 30% WPI. The demonstration of the good compatibility of WPI hydrogels with endothelial cells in these experiments is an important step towards promoting the vascularization of hydrogels upon implantation in vivo, which is expected to improve implant outcomes in the future.

Preparation and structural characterization of pullulan and whey protein isolate-based electrospun nanofiber

The impact of blended ratios was analyzed on the development and characterization of electrospun fibers using various combinations of pullulan (PUL) and whey protein isolate (WPI). The physical parameters like apparent viscosity, electrical conductivity and surface tension of blended solutions were improved after the addition of PUL in the blends, resulting in a uniform electrospun nanofiber. Scanning electron microscope (SEM) of nanofibers revealed bead-free, smooth and uniform structural conformation. Whereas, the uniformity of nanofiber was compromised by using higher concentrations of WPI in the blend. Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD) and Thermogravimetry analysis further confirmed the strong molecular interaction between polysaccharide and protein. The incorporation of WPI in PUL based electrospun nanofibers enhanced hydrophobicity, potentially facilitating the delivery of bioactive compounds. The WPI and PUL:WPI-based nanofibers demonstrated robust antioxidant potential, due to the presence of total phenolic contents (TPC). The stability of PUL interaction with WPI (β-lactoglobulin and α-lactalbumin) was confirmed through hydro-carbon (C–H) and hydrogen bond interactions by molecular docking. Finally, we can conclude that polysaccharide and protein-based nanofiber can be used to deliver bioactive compounds in food and pharmaceutical industries.

Lesser mealworm (A. diaperinus) protein as a replacement for dairy proteins in the production of O/W emulsions: Droplet coalescence studies using microfluidics under controlled conditions

Dairy proteins are commonly used to stabilize oil-in-water (O/W) emulsions, which can be replaced by other sustainable sources of proteins, such as insects. This study investigated the potential of lesser mealworm protein concentrate (LMPC) as a sustainable alternative to whey protein isolate (WPI) in stabilizing oil-in-water (O/W) emulsions using microfluidics. The frequency of coalescence (Fcoal) was calculated using images of emulsion droplets obtained near the inlet and outlet of the coalescence channel. The stability of O/W emulsions, produced using sunflower oil (SFO) or hexadecane and stabilized with varying concentrations of LMPC and WPI (0.02% to 0.0005% w/v), was compared under controlled conditions. The dispersed phase fraction (5.3%-14.3% v/v), protein adsorption time onto oil droplets (0.0398–0.158 s), and pH (pH = 3 and pH = 7) were also studied. Fcoal was greatest (0.42 s−1) when the protein concentration was lowest (0.0005%), the oil percentage was highest (14.3%), the adsorption period was shortest (0.0398 s), and the pH was 3. Droplet diameters did not vary significantly, with values between 55 and 118 μm, across protein concentrations or adsorption periods, but a rise in oil fraction resulted in a substantial increase in droplet diameters. Increases in protein content, adsorption duration, and oil percentage all resulted in increased stability (reduction of Fcoal). While LMPC and WPI showed similar results in microfluidic experiments and other test conditions, further research is needed to verify LMPC's efficacy as a replacement for WPI in food emulsification. Nonetheless, the findings suggest that LMPC has potential as a substitute for WPI in this application.

Studying structural and rheological properties of alginate-whey protein isolate cold-set hybrid emulgels at various pH levels.

Effects of different pH values (4-7) and whey protein isolate (WPI) concentrations (0.5-1.5%) were evaluated on physical, mechanical, and rheological properties of cold-set alginate-based soybean oil hybrid emulgels. The pH value changes were more effective than WPI concentration changes on emulgel properties. According to syneresis and texture profile analysis results, 1% WPI was selected as the optimum concentration. The XRD analysis showed that calcium alginate (CA) emulgel at pH 6 had a different peak at 2θ of 14.8°, likely indicating the highest amount of ion-bridging and maximum number of junction zones. The homogeneity of CA and CA + WPI emulgels (determined by image entropy analysis) decreased by pH reduction from 7 to 4, which can be related to acid-induced intermolecular interactions between alginate chains. The rheological properties of CA and CA + WPI emulgels revealed predominant elastic character (G' > G'') at different pH values. Creep test results showed that the relative recovery of emulgel prepared at pH 7 and 5 was 18.10 and 63.83%, respectively, suggesting pH reduction contributed to increase in the elastic component of material. The findings of this study can be applied for developing structured cold-set emulgels as solid fat replacers in meat and dairy products.

Proliferation kinetics and mineralization properties of MC3T3‐E1 cells on whey protein isolate scaffolds for bone tissue regeneration

AbstractThe purpose of the study is to assess the influence of scaffold composition and properties on the cellular proliferation and scaffold mineralization on a whey protein isolate (WPI) scaffold. Scaffolds of varying concentrations of WPI, calcium chloride, and amylopectin are seeded with cells, and growth curves are constructed from cell density measurements following incubation. Non‐linear regression yields kinetic growth parameters which are compared for quantitative assessment of scaffold performance. Scaffolds show biocompatibility and the ability to sustain a culture for the length of the study. For up to 14 days, the data are well described by exponential growth. Thereafter, saturation behavior appears, and the data fit well to a sigmoidal model. The seeding efficiency improves with increasing WPI concentration, peaking at 5 mM CaCl2, and decreases with added amylopectin. The growth constant is almost independent of scaffold composition, with possible increases with added CaCl2 and amylopectin. The retardation constant is independent of composition. Scaffolds cultured in differentiation and mineralization conditions, shows development of a mineralized matrix both on acellular scaffold surfaces and in osteoblast cultures. The ability of the unmodified WPI gel surfaces to promote the growth and differentiation of a model preosteoblast provides valuable trends and concentration effects for further scaffold design.

Evaluation of ionic calcium and protein concentration on heat- and cold-induced gelation of whey protein isolate gels as a potential food formulation for 3D food printing

3D food printing (3DFP) is an innovative food process, but developing foods with ideal printability can prove challenging. Whey protein isolate (WPI) gels can be difficult to print due to their rigidity. This study evaluated the cold- and heat-induced gelation properties of WPI for use in 3DFP. Initially, the effect of WPI concentration ([WPI]) (8–12% (w/w)) and ionic calcium concentration ([Ca2+]) (0–8 mM) was evaluated on the heat-induced gelation capability and thermal reversibility. Treatments were categorised into three groups: thermo-irreversible, thermo-reversible, and non-gelling. Non-gelling treatments were used for cold-induced gelation by mixing the denatured WPI solution with 150 mM Ca2+ solution. Thermo-reversibility and cold-induced gelation properties were assessed using oscillatory rheometry. Finally, thermo-irreversible gels (TIRG) were characterised using extrudability and texture profile analysis. The thermo-reversible gels had an unsuitable range of G' (5–60 Pa) and δ (40–60°) for obtaining a self-standing object. Cold gelation using [WPI] = 10%, G' > 500 Pa and δ < 10°, may be suitable for 3DFP but requires an adapted extrusion-based 3D printer, i.e., co-extrusion, cooling or support bath. The extrusion force of TIRG decreased during heating and was mainly affected by [WPI]. Upon re-cooling, the force recovered (>85%) with the addition of [Ca2+] > 4 mM. TIRG using the following treatments [WPI]-[Ca2+] = 12% - 2 mM, 11% - 4 mM, and 10% - 6 mM demonstrated good printability. Principal component analysis showed TIRG with low hardness, resilience, and extrusion force loss during heating are potentially suitable for 3DFP.

Microencapsulation of marjoram essential oil as a food additive using sodium alginate and whey protein isolate

Encapsulation techniques are generally used to preserve the volatile compounds of essential oils. This study aimed to evaluate the influence of process variables on the microencapsulation of marjoram essential oil (MEO) (Origanum majorana L.) by ionic gelation. The effect of sodium alginate concentration (0.5–2 g/100 mL), emulsifier concentration (0.5–2 g/100 mL whey protein isolate (WPI)), and cationic bath concentration (0.05–0.3 mol/L CaCl2) on the emulsions and beads properties were investigated, according to a rotatable central composite design. MEO chemical composition and antimicrobial activity were assessed. Emulsions were characterized for droplet size and viscosity, while the particles were analyzed for encapsulation efficiency, size and circularity, and morphology. High concentrations of alginate and WPI intensified the porous structure of the beads, reducing droplet mean diameter and encapsulation efficiency. High alginate concentrations also increased emulsion viscosity, affecting positively beads' circularity. The intermediate concentration of sodium alginate (1.25 g/100 mL), WPI (1.25 g/100 mL), and CaCl2 (0.175 mol/L) were selected as the most appropriate conditions to produce beads with satisfactory circularity and high encapsulation efficiency.

Application of LF-NMR to characterize the roles of different emulsifiers in 3D printed emulsions

This study established a 3D printed food emulsions stabilized by whey protein isolate (WPI), hydroxypropylated starch (HS) and carrageenan. Low field nuclear magnetic resonance (LF-NMR) was applied to reveal role of WPI, HS and carrageenan on the mobility of hydrogen protons in these emulsions. T 2 distribution of 2% WPI and HS suspensions showed different hydrogen populations. And a new peak T 21 representing single layer water protons appeared at higher concentration. While T 21 was not found in all carrageenan dispersions. Rising of WPI, HS and carrageenan concentration all led to decline in T cur and T 2W values. For emulsions, increasing WPI concentration from 2% to 6% led to decrease in T 2W and T cur . Decreasing WPI/HS ratio prolonged the decay process as both T 2W and T cur values grew. Four proton signals showed in T 2 profile of most emulsions. The T 25 free water signal was closely correlated with WPI, HS, and carrageenan concentration. Decrease in T 24 peak time were observed when increasing WPI content. Influence of carrageenan on proton mobility of the emulsions were complicated and concentration-dependent, affecting relaxation peak T 21 , T 22 , T 24 , and T 25 . Apparent viscosity and rheological parameters G’ and G” indicated the emulsions exhibiting shear-thinning behavior with gel-like structure. Microstructure study revealed that addition of HS and carrageenan resulted in decline in emulsion droplet size. The printability of these WPI-stabilized emulsions was greatly affected by carrageenan content. Overall, this study proved the feasibility of using LF-NMR as a fast and effective approach for characterizing the effect of different emulsifiers in 3D printed emulsions when various types of emulsifiers existed. • LF-NMR can be used to rapidly characterize the roles of different emulsifiers in emulsions. • Relaxation behavior of emulsions were influenced by the type and concentration of emulsifiers used. • Microstructure, rheological properties, and 3D printability of emulsions were evaluated.