Improving the Three-Dimensional Printability of Potato Starch Loaded onto Food Ink.

This study focuses on improving the 3D printability of pea protein with the help of food inks designed for jet-type 3D printers. Initially, the food ink base was formulated using nanocellulose-alginate with a gradient of native potato starch and its 3D printability was evaluated. The 3D-printed structures using only candidates for the food ink base formulated with or without potato starch exhibited dimensional accuracy exceeding 95% on both the X and Y axes. However, the accuracy of stacking on the Z-axis was significantly affected by the ink composition. Food ink with 1% potato starch closely matched the CAD design, with an accuracy of approximately 99% on the Z-axis. Potato starch enhanced the stacking of 3D-printed structures by improving the electrostatic repulsion, viscoelasticity, and thixotropic behavior of the food ink base. The 3D printability of pea protein was evaluated using the selected food ink base, showing a 46% improvement in dimensional accuracy on the Z-axis compared to the control group printed with a food ink base lacking potato starch. These findings suggest that starch can serve as an additive support for high-resolution 3D jet-type printing of food ink material.

Correlationship between self-assembly behavior and emulsion stabilization of pea protein-high methoxyl pectin complexes treated with ultrasound at pH 2.0.

This study investigated the effects of ultrasound on the self-assembly behavior of pea protein (PP)-high methoxyl pectin (HMP) complexes at pH 2.0 through transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and intrinsic fluorescence analysis. The emulsion stabilization mechanism of PP-HMP treated with ultrasound (PP-HMP-US) was also elucidated. The results indicated that ultrasound increased the emulsifying activity index (EAI) and emulsifying stability index (ESI) of PP-HMP. Moreover, PP-HMP-US-based emulsions formed small, dispersed oil drops, which were stable during storage. PP-HMP- and PP-HMP-US-based emulsions did not demonstrate any creaming. The TEM results revealed that ultrasound can regulate the self-assembly behavior of PP and HMP to form spherical particles with a core-shell structure. This structure possessed low turbidity, a small particle size, and high absolute zeta potential values. The FTIR and intrinsic fluorescence spectra demonstrated that ultrasound increased the α-helix and ß-sheet contents and exposed the tryptophan groups to more hydrophilic environments. Ultrasound also promoted the PP-HMP self-assembly through electrostatic interaction and improved its oil-water interfacial behavior, as indicated by the EAI and ESI values of PP-HMP-US-based emulsions. The current results provide a reference for the development of an innovative emulsifier prepared by ultrasound-treated protein-pectin complexes at low pH.

Physico-chemical properties of an innovative gluten-free, low-carbohydrate and high protein-bread enriched with pea protein powder.

The study aimed to determine the effect of pea protein powder on the pasting behavior and physico-chemical properties including the composition of amino and fatty acids of gluten-free bread with low-carbohydrate content. The control bread recipe was based on buckwheat flour (50 g) and flaxseed flour (50 g) as main flours. Additionally, the improving additives for this control bread such as psyllium husk (4 g), potato fiber (2 g), and guar gum (2 g) were used. The mixture of base flour was supplemented with the addition of pea protein powder (PPP) in the amount ranging from 5 to 25%. The results of Visco analyzes measured by RVA apparatus showed that the addition of 10% PPP to the control bread did not significantly differentiate peak viscosity and pasting temperature which was at the level 3115 cP and 3149 cP and 50 °C, respectively. Supplementation of low-carbohydrate bread with 10% of PPP was acceptable and significantly increased the content of all analyzed amino acids, as well as the amount of α-linolenic acid concerning the control bread. The lowest value of chemical score was observed for leucine. The EAAI (essential amino acid index) value increased from 34 to 40 when the optimal protein supplement was added. The developed gluten-free, low-carbohydrate, and high protein bread was characterized by contents of carbohydrate of 16.9%, protein of 17.1%, fiber of 13.7%, fat of 3.3% and its calorific value was 194 kcal/100 g.

High internal phase pickering emulsions stabilized by pea protein isolate-high methoxyl pectin-EGCG complex: Interfacial properties and microstructure.

The pea protein isolate-high methoxyl pectin-epigallocatechin gallate (PPI-HMP-EGCG) complex was used to stabilize Pickering emulsions (PEs) and high internal phase PEs (HIPPEs), and the effect of interfacial rheology on the microstructure, bulk rheology and stability of these emulsions was investigated. The PPI-HMP-EGCG complex with PPI to EGCG 30:1 exhibited partial wettability (81.6 ± 0.4°) and optimal viscoelasticity for the formation of stable interfacial layer. The microstructure demonstrated that the PPI-HMP-EGCG complex acted as an interfacial layer and surrounded the oil droplets, and continuous phases were mainly filled with excessive HMP, which enhanced emulsion stability. The formation of a firm gel-like network structure required a dense interfacial layer to provide the PEs (complex concentration of 0.1%) and HIPPEs (oil-phase up to 0.83) with ideal viscoelasticity and stability. The results provide the guidelines for the rational design of EGCG-loaded HIPPEs stabilized by water-soluble protein/polysaccharide complexes.

Effect of sesamol on the physical and chemical stability of plant-based flaxseed oil-in-water emulsions stabilized by proteins or phospholipids.

Plant-based polyphenols are increasingly being explored as functional ingredients in emulsified food systems. In this study, the effects of sesamol on the physical and chemical stability of flaxseed oil-in-water emulsions stabilized by either phospholipids (sunflower) or proteins (whey or pea) were investigated. In the absence of sesamol, the protein-based emulsions displayed better physical stability than the phospholipid-based ones, which was related to their smaller particle diameter and higher particle charge. For the phospholipid-based emulsions, sesamol addition did not improve their physical stability, but it did inhibit lipid oxidation. In particular, it decreased the formation of secondary oxidation products, with a 65% reduction in TBAR formation compared to the control after 8 days of storage. For the protein-based emulsions, sesamol addition reduced particle aggregation and inhibited lipid oxidation, reducing the secondary oxidation products by around 85% after 19 days of storage. The inhibitory efficiency of sesamol in the pea protein-based emulsions was comparable to that in the whey protein-based ones. The effects of sesamol on the physical and chemical stability of the emulsions were related to its partitioning between the oil, water, and interfacial layers. This study suggests that adding sesamol to plant-based emulsions may improve their physical and chemical stability, thereby extending their shelf life.

Fabrication, structural characterization and functional attributes of polysaccharide-surfactant-protein ternary complexes for delivery of curcumin.

In this study, the nanocomplexes as a novel delivery system for curcumin, were successfully fabricated using high methoxyl pectin (HMP), individual surfactants (rhamnolipid (Rha), tea saponin (TS) and ethyl lauroyl arginate hydrochloride (ELA)) and pea protein isolate (PPI). The optimum mass ratio between PPI and curcumin was 40:1. The HMP-Rha-PPI-Cur, HMP-TS-PPI-Cur and HMP-ELA-PPI-Cur complexes which had particle sizes of 453, 422 and 587 nm, exhibited encapsulation efficiencies of curcumin with 93.46, 92.05 and 86.73%, respectively. The analysis of FTIR revealed that HMP-surfactant-PPI-Cur complexes were formed mainly by hydrogen bonding and electrostatic attraction. XRD result showed that curcumin exhibited a non-crystallized state in the ternary complexes. Moreover, the curcumin within the HMP-Rha-PPI ternary complexes showed better stability under UV-light, thermal and simulated gastrointestinal conditions.

Effect of different levels of esterification and blockiness of pectin on the functional behaviour of pea protein isolate-pectin complexes.

This research examines changes to the functional (solubility, emulsifying and foaming) properties of pea protein isolate when complexed with commercial citrus pectin of different structural attributes. Specifically, a high methoxy (P90; degree of esterification: 90.0%; degree of blockiness: 64.5%; galacturonic acid content 11.4%) and low methoxy (P29; degree of esterification: 28.6%; degree of blockiness: 31.1%; galacturonic acid: 70%) pectin at their optimum mixing ratios with pea protein isolate (4:1 pea protein isolate to P90; 10:1 pea protein isolate to P29) were assessed at the pHs associated with critical structure forming events during the complexation process (soluble complexation (pHc), pH 6.7 and 6.1; insoluble complex formation (pHϕ1), pH 4.0 and 5.0; maximum complexation (pHopt), pH 3.5 and 3.8; dissolution of complexes, pH 2.4 and 2.1; for admixtures of pea protein isolate-P90 and pea protein isolate-P29, respectively). Pea protein isolate solubility was improved from 41 to 73% by the presence of P90 at pH 6.0 and was also moderately increased at pH 4.0 and pH 5.0 by P90 and P29, respectively. The emulsion stability of both pea protein isolate-pectin complexes was higher than the homogeneous pea protein isolate at all critical pHs except pHopt as well as pHc for pea protein isolate-P29 only. P90, with the higher level blockiness and esterification, displayed better foaming properties at the maximal complexation pH when complexed with pea protein isolate than pea protein isolate-P29 or pea protein isolate alone. However at pHϕ2, pea protein isolate-P29 admixtures produced foams with 100% stability, increasing pea protein isolate foam stability by 85%. The enhanced functionality of pea protein isolate-pectin complexes based on the type of pectin used at critical pHs indicates they may be useful biopolymer ingredients in plant protein applications.

Encapsulation of pea protein in an alginate matrix by cold set gelation method and use of the capsules in fruit juices.

Plant-based proteins gained importance in recent years due to the increase in the awareness of healthy diet and in the consumption of plant-based foods. However, some features of plant-based proteins like the undesirable odor and flavor affect the sensorial properties of protein containing foods. Therefore, encapsulation of these proteins could be a good strategy to tackle with this problem. The objective of this study was to design microcapsules (beads) consisting of pea protein by using sodium alginate and to investigate the effect of different alginate concentrations (1.0, 1.5, and 2.0%) on the protein content, encapsulation efficiency, particle size, bead stability, and the morphology of the capsules and then add them to different fruit juices (pomegranate and melon) and examine the release behavior from the capsules. Rheological behavior of the juices including pectin were also investigated. TD- nuclear magnetic resonance relaxometry analysis through T2 relaxation times was conducted on the capsules to observe the changes in the beads. In conclusion, alginate was found to be a suitable encapsulation coating for pea protein. Beads containing 1% alginate concentration was found to be the most effective with respect to protein content and bead stability. PRACTICAL APPLICATION: This study aims to design and characterize pea protein containing microcapsules capsules and their utilization in fruit juices. The study itself focused on a specific application on the fruit juices.

Combining solid dispersion-based spray drying with cyclodextrin to improve the functionality and mitigate the beany odor of pea protein isolate.

The beany flavor of pea protein limits its application in the food industry. This study aimed at addressing this problem by combining the advantages of solid-based spray drying technique and the ability of cyclodextrins (CD) to entrap volatiles. Pea protein isolates (PPI) was extracted by alkaline extraction-isoelectric precipitation, followed by co-spray drying with CD. The resulted PPI-CD showed no major structure changes. HS-SPME-GC-MS coupled to untargeted metabolomics successfully identified 23 aroma compounds that represent the different odorants among PPI-control, physically mixed PPI-CD, and co-spray dried PPI-CD samples. Heat map analysis also showed a remarkable beany odor mitigation effect upon the addition of CD, which was further proved to be due to CD entrapping aroma compounds during spray drying. In the meantime, the functional attributes of PPI-CD were not adversely impacted by the addition of CD.

Utilization of plant-based protein-polyphenol complexes to form and stabilize emulsions: Pea proteins and grape seed proanthocyanidins.

Plant-based proteins and polyphenols are increasingly being explored as functional food ingredients. Colloidal complexes were prepared from pea protein (PP) and grape seed proanthocyanidin (GSP) and the ability of the PP/GSP complexes to form and stabilize oil-in-water emulsions were investigated. The main interactions between PP and GSP were hydrogen bonding. The stability of PP-GSP complexes to environmental changes were studied: pH (2-9); ion strength (0-0.3 M); and temperature (30-90 °C). Emulsions produced using PP-GSP complexes as emulsifiers had small mean droplet diameters (~200 nm) and strongly negative surface potentials (~-60 mV). Compared to PP alone, PP-GSP complexes slightly decreased the isoelectric point, thermostability, and salt stability of the emulsions, but increased their storage stability. The presence of GSP gave the emulsions a strong salmon (red-yellow) color, which may be beneficial for some specific applications. These results may assist in the creation of more efficacious food-based strategies for delivering proanthocyanidins.

Impact of alcohol washing on the flavour profiles, functionality and protein quality of air classified pea protein enriched flour.

In this study the potential of aqueous solvent washing on removing off-flavours in air classified pea protein-enriched flour (PPEF) was investigated. Unpleasant flavour compounds are one of the main deterrents to the application of pulses. PPEF was treated with ethanol or isopropanol at three different concentrations (20%, 50%, and 80%) to remove the volatiles related to unpleasant beany, earthy and astringent flavours. Headspace solid phase microextraction followed by GC-MS was used to identify the flavour compounds in untreated and treated PPEF. Besides the flavour profile, changes to their proximate composition, colour, functionality and protein quality were compared among untreated and treated samples. Higher concentrations of ethanol and isopropanol (50% and 80%) showed greater effectiveness in removing flavour compounds by reducing the total peak area by 82%-94%. Protein content in all treated samples (58.2%-64.3% d.b.) increased compared to untreated PPEF (55.5%) as a result of purification due to the decrease in ash, lipid and carbohydrate content. However, alcohol treatment reduced the protein solubility and oil holding capacity in all samples by 38.3%-75.9%, and 16.7%-30.2%, respectively. Although in vitro protein digestibility was improved with the solvent treatments, the amino acid scores of those samples became lower (i.e., reduced levels of methionine, cysteine or tryptophan) resulting in up to a 27.8% reduction in in vitro protein digestibility correct amino acid scores. Both ethanol and isopropanol at 50% and 80% concentration proved to be effective in removing flavour compounds in PPEF with some modifications on the chemical compositions, protein functionalities and quality.

Development of high methoxyl pectin-surfactant-pea protein isolate ternary complexes: Fabrication, characterization and delivery of resveratrol.

The purpose of this study was to fabricate ternary complexes composed of pea protein isolate (PPI), high methoxyl pectin (HMP) and individual surfactants including rhamnolipid (Rha), tea saponin (TS) and Ethyl lauroyl arginate (LAE), for the delivery of resveratrol (Res). A combination of electrostatic attraction and hydrophobic interaction was dominantly responsible for the formation of HMP-surfactant-PPI complexes. The physicochemical properties of the ternary complexes were affected by surfactant types as well as mass ratios of individual surfactant to PPI. HMP-Rha-PPI1:1, HMP-TS-PPI1:1 and HMP-LAE-PPI1:25 complexes had higher denaturation temperatures of 82.78 ± 0.31, 80.21 ± 0.02 and 79.98 ± 0.86 ℃, respectively. The HMP-Rha-PPI1:1 ternary complex could be an effective delivery system, which were effective to retard photo- and thermal- degradation of Res as well as delayed the release of Res in in vitro digestion.

Transglutaminase modifies the physical stability and digestibility of chickpea protein-stabilized oil-in-water emulsions.

This study sought to utilize enzymatic crosslinking to modulate the properties of chickpea-stabilized o/w emulsions and determine its effect on digestibility. Oil-in water emulsions were produced from 40% corn oil and 6% chickpea protein (w/w) with/without addition of transglutaminase (TG). Crosslinking increased the particle size and poly-dispersity, and led to the formation of a gel-like structure (G' > G″) with 1.5 order of magnitude higher G' compared to the non-crosslinked emulsion. Enzyme addition improved the emulsion physical stability (over a month) compared to the non-crosslinked emulsion that showed phase separation after two weeks of storage. Results of in vitro digestion showed decreased digestibility of TG-crosslinked chickpea-stabilized emulsions, while proteomic analysis revealed that the crosslinked emulsion is a source of bioactive peptides that are liberated by human digestive enzymes. Overall, application of TG can rationally modify the functionality and digestibility of o/w emulsions towards positive effects on human health.

Fabrication of curcumin-loaded pea protein-pectin ternary complex for the stabilization and delivery of ß­carotene emulsions.

There is an ever-increasing need to protect health-beneficial ß-carotene (BC) from degradation with novel ingredients. Natural antioxidant-loaded protein-polysaccharide ternary complex has great potential for BC emulsions stabilization. In this study, curcumin (CUR)-loaded pea protein isolate (PPI), and high methoxyl pectin (HMP) ternary complex (804.0 nm) was fabricated by a self-assembly approach for BC emulsions stabilization. Highest CUR loading amount (LA, 33.19 µg/mg) was obtained in CUR-PPI-HMP complex. Hydrophobic interaction and hydrogen bonding were the prime driving forces for ternary complex formation. XRD results showed that CUR was amorphous. BC emulsion with PPI-HMP and CUR-PPI-HMP possessed higher droplet sizes (357.8 and 360.2 nm) than that with PPI and CUR-PPI (325.6, and 313.5 nm). Excellent physical stability with PPI-HMP and CUR-PPI-HMP was observed. BC retention with CUR-PPI-HMP was highest exposure to UV light (76.15%, 8 h), or heat treatment at 25 (91.50%) and 50 °C (74.35%) for 30 days.

Pea protein based vitamin D nanoemulsions: Fabrication, stability and in vitro study using Caco-2 cells.

Pea protein-stabilized nanoemulsions were prepared to encapsulate vitamin D with the aim to develop novel non-dairy functional foods for vitamin D fortifications. Homogenization conditions of 20 kpsi and two homogenization cycles were identified as optimal conditions for producing stable nanoemulsions. The nanoemulsions exhibited controllable sizes (170-350 nm), good stability with zeta-potential of -25 mV, and high vitamin encapsulation efficiency (94-96%). Cellular uptake efficiency of small sized nanoemulsions (233 nm) was ~2.5 times higher than large sized nanoemulsions (350 nm). Interestingly, protein-based nanoemulsions exhibited significantly higher cellular uptake than emulsions prepared using a combination of protein and lecithin. The vitamin D transport efficiency across Caco-2 cells for small sized nanoemulsions (233 nm) was ~5.3 times greater than free vitamin D suspension. This research demonstrated that pea protein can be used as an effective emulsifier for preparing food nanoemulsions, which may enhance vitamin D bioavailability and improve vitamin deficiency status in aged population.

Effect of enzyme de-esterified pectin on the electrostatic complexation with pea protein isolate under different mixing conditions.

Native high methoxy citrus pectin (NP) was de-esterified by pectin methyl esterase to produce modified pectins [MP (42, 37, and 33)] having different degrees of esterification. Complex coacervation between a pea protein isolate (PPI) and each pectin was investigated as a function of pH (8.0-1.5) and mixing ratio (1:1-30:1, PPI-pectin). Complex formation was found to be optimal for biopolymer-mixing ratios of 8:1, 8:1, 25:1 and 25:1 for PPI complexed with NP, MP42, MP37 and MP33, respectively, at pHs 3.6, 3.5, 3.9 and 3.9. And, the critical pHs associated with complex formation (accessed by turbidity) was found to shift significantly to higher pHs as the degree of esterification of the pectin decreased, whereas the shift in the pH corresponding to their initial interactions was minimal with degree of esterification. Complexation of PPI with NP and MP42 greatly improved the protein solubility.

Phase behavior and complex coacervation of concentrated pea protein isolate-beet pectin solution.

This study aimed to develop an alternative method named state diagram to identify boundary formation pH for complex coacervates between pea protein isolate (PPI) and sugar beet pectin (SBP) at concentrated solutions (~2.0 wt%). The effects of pH (7-2) and PPI-SBP mixing ratios (1:1-20:1) on coacervates formation were investigated by state diagram, zeta-potential, rheological, and phase composition analysis. Isothermal titration calorimetry, scanning electron microscopy, and Fourier transform infrared spectroscopy were employed to elucidate thermodynamic behaviors, non-covalent bonding of coacervates, and microstructure of coacervates. We demonstrate that state diagram can explicitly identify the three characteristic pH values (pHφ1, pHopt, and pHφ2) at which recognizable transitions take place in concentrated colloids solutions. The mixing ratio dependent of pHφ1 increased to pH 5.5 as PPI-SBP mixing ratio increased to 20:1. The pHopt was recognized at the net charge neutrality or the highest storage modulus of the mixed colloids solutions.

Fabrication of pea protein-tannic acid complexes: Impact on formation, stability, and digestion of flaxseed oil emulsions.

There is growing interest in the identification of plant-based functional ingredients for utilization within the food industry. Complexes were fabricated from pea protein (PP) and tannic acid (TA) and then their ability to act as antioxidant emulsifiers in flaxseed oil-in-water emulsions was studied. PP-TA complex formation was investigated using isothermal titration calorimetry and turbidity analysis, which suggested hydrogen bonding and hydrophobic interactions were important in their assembly. PP-TA-stabilized emulsions containing small droplets could be formed at relatively high TA levels. Moreover, PP-TA complexes had strong antioxidant activity, which extended the shelf life of flaxseed oil emulsions. The composition of the PP-TA complexes impacted the aggregation state of the lipid droplets under simulated gastric conditions, which affected the rate and extent of lipid digestion. This study shows PP-TA complexes can be used for fabricating flaxseed oil delivery systems with enhanced oxidative stability and good digestibility.

Pea Protein for Hempseed Oil Nanoemulsion Stabilization.

In this paper, we present the possibility of using pea protein isolates as a stabilizer for hempseed oil (HSO)-based water/oil emulsions in conjunction with lecithin as a co-surfactant. A Box-Behnken design was employed to build polynomial models for optimization of the ultrasonication process to prepare the emulsions. The stability of the system was verified by droplet size measurements using dynamic light scattering (DLS) as well as centrifugation and thermal challenge tests. The z-ave droplet diameters of optimized emulsion were 209 and 207 nm after preparation and 1 week storage, respectively. The concentration of free Linoleic acid (C18:2; n-6) was used for calculation of entrapment efficiency in prepared nanoemulsions. At optimum conditions of the process, up to 98.63% ± 1.95 of entrapment was achieved. FTIR analysis and rheological tests were also performed to evaluate the quality of oil and emulsion, and to verify the close-to-water like behavior of the prepared samples compared to the viscous nature of the original oil. Obtained results confirmed the high impact of lecithin and pea protein concentrations on the emulsion droplet size and homogeneity confirmed by microscopic imaging. The presented results are the first steps towards using hempseed oil-based emulsions as a potential food additive carrier, such as flavor. Furthermore, the good stability of the prepared nanoemulsion gives opportunities for potential use in biomedical and cosmetic applications.

Effect of alkaline de-esterified pectin on the complex coacervation with pea protein isolate under different mixing conditions.

High methoxy citrus pectin (UM88) was saponified to produce modified pectin [M(72, 42, and 9)], with different levels of degree of esterification (DE), to investigate the complex coacervation of pea protein isolate (PPI) with pectin [UM88 and M(72, 42, and 9)]. Regardless of the DE value of pectin, the critical pH corresponding to when insoluble complexes form shifted to higher pH as the mixing ratio increased. The maximum amount of coacervates formed at a biopolymer-mixing ratio of 8:1, 8:1, 10:1 and 15:1 for PPI with UM88, M72, M42, and M9, respectively. Maximum interactions for the protein-pectin admixtures occurred between pH 3.70 and 3.85. PPI complexed with modified pectin displayed greater interactions under their optimal mixing conditions compared to the unmodified pectin. The de-esterification of pectin resulted in more rigid and stiffer pectin, which enhanced its interaction with PPI by shifting the critical parameters to a higher value.