Phase behavior, thermodynamic and microstructure of concentrated pea protein isolate-pectin mixture: Effect of pH, biopolymer ratio and pectin charge density

Phase behavior and synergistic gelation of scallop (Patinopecten yessoensis) male gonad hydrolysates and gellan gum driven by pH

BACKGROUND

Previous studies have investigated complexation and coacervation of scallop Patinopecten yessoensis male gonad hydrolysates (SMGHs) and polysaccharides influenced by pH and blending ratio. It has been found that SMGHs/polysaccharide composite shows better gel properties under strongly acidic conditions. Thus, the complexation and coacervation of SMGHs and gellan gum (GG) were investigated via turbidimetric titration at different pH values (1-12) and biopolymer blending ratios (9.5:0.5-6:4).

RESULTS

Both pHc and pHφ1 exhibited ratio-independent behavior with constant values at approximately pH 5.8 and pH 3.8, respectively, dividing SMGHs/GG blends into three phases named mixed polymers, soluble complexes and insoluble coacervates, respectively. Overall, SMGHs and GG exhibited synergistic gelation under neutral and acidic conditions, with the initial storage modulus (G') increasing by approximately 42.5-, 573.7- and 3421-fold and 97.7-, 550.3- and 0.5-fold, respectively, at pH 7, 5 and 3, compared with SMGHs and GG. As pH decreased from 7 to 3, the initial G' and viscosity η values of SMGHs/GG gels increased by 20.1- and 2.3-fold, respectively, exhibiting the greatest increase in gel strength. Moreover, the free water in the SMGHs/GG system significantly shifted toward lower relaxation times attributed to the immobilization of the outer hydration layers. SMGHs/GG gels in the insoluble phase exhibited denser networks and rougher surfaces, supporting the enhanced rheological properties and water retention capacity of the gel.

CONCLUSION

This work provides a basic foundation for the development of pH-driven SMGHs/GG gelation by examining complexation and coacervation processes. © 2024 Society of Chemical Industry.

Effects of different solid particle sizes on oat protein isolate and pectin particle-stabilized Pickering emulsions and their use as delivery systems

Oat protein isolate (OPI)/high methoxyl pectin (HMP) complexes (OPP) were prepared to stabilized Pickering emulsions and applied as nutraceutical delivery systems. The different mass ratios and pH changed the interactions between OPI and HMP that caused the different size of OPP. Specifically, smaller particle size of OPP (125.7-297.6 nm) were formed when hydrophobic interactions along with electrostatic forces predominant in OPP (OPI:HMP = 3:1, pH 4, 5). Among these particles, OPP-2 could stabilize Pickering emulsion efficiently through formation of dense interfacial film, which exhibited the highest apparent viscosity and the smallest average droplet size (23.39 μm). Moreover, OPP-2 stabilized Pickering emulsions with superior stability not only exhibited higher encapsulation efficiency of 85.63%, but also could control curcumin release in simulated gastrointestinal fluids to improve curcumin's bioaccessibility. These results verified the possibility of OPP to be a Pickering emulsions stabilizer, and also identified its potential to be a stable delivery system for bioactive compounds.

Ultrasonic-microwave technique promotes the physicochemical structure of hydrogel and its release characterization of curcumin in vitro

In this study, soybean protein isolate and hawthorn pectin were mixed to prepare binary hydrogels using ultrasound and microwave techniques. Moderate treatment can not only significantly improve the mechanical strength of the hydrogel, but also increase the tightness of the internal cross-linking. The strengthening of interactions (hydrogen bonds, hydrophobic interactions, and disulfide bonds) was the main reason for this trend. Especially, the ultrasonic-microwave (80 s) treatment hydrogel possessed excellent hardness (33.426 N), water-holding capacity (98.26%), elasticity (G' = 1205 Pa), and a more homogeneous and denser microstructure. In addition, the hydrogel minimized the extent of curcumin loss (21.23%) after 5 weeks of storage. In general, the ultrasonic-microwave technique could significantly promote the physicochemical structure and curcumin bioaccessibility of hydrogels, which showed excellent market prospects in the food industry.

Pea protein isolate-soluble soybean polysaccharides electrostatic assembly: effect of pH, biopolymer mass ratio and heat treatment

BACKGROUND

In past years, thousands of protein-polysaccharide complexes have been investigated to modify protein characteristics and functionality in food systems. However, the interaction between pea protein isolate (PPI) and soluble soybean polysaccharide (SSPS) has not been thoroughly characterized yet.

RESULTS

In the present study, the phase behavior of PPI and SSPS mixtures was analyzed as a function of PPI:SSPS mixing ratio (1:1 to 1:0.10) and pH (7.0 to 2.0), showing that these biopolymers could be electrostatically assembled at 1:1 to 1:0.25 mixing ratios and 4.0 to 3.0 pH values. Then, the characteristics of the PPI-SSPS complexes were studied before and after heating (90 °C and 30 min) by ζ-potential, surface hydrophobicity, protein solubility, particle size distribution and physical stability for 56 days. By lowering the pH and PPI:SSPS mixing ratio, the complexes showed increased solubility, changed 𝜁-potential and higher physical stability. By heating, the complexes presented increased hydrophobicity and physical stability.

CONCLUSION

Overall, PPI-SSPS complexes increased the protein solubility, reduced the particle size, and changed both the ζ-potential and the surface hydrophobicity with respect to PPI control, allowing stabilization of the colloidal system and broadening the possible applications of these high-quality proteins in acidic food systems. © 2024 Society of Chemical Industry.

Preparation and characterization of zein-caseinate-pectin complex nanoparticles for encapsulation of curcumin: pectin extracted by high-speed shearing from passion fruit (Passiflora edulis f. flavicarpa) peel

BACKGROUND

Pectin extracted by high-speed shearing from passion fruit peel (HSSP) is a potentially excellent wall material for encapsulating curcumin, which has multiple advantages over pectin prepared by heated water extraction. HSSP was used to fabricate complex nanoparticles of zein-sodium caseinate-pectin for encapsulation of curcumin in this study. The influence of heating on the physicochemical properties of the composite nanoparticles was also investigated, as well as the effect of composite nanoparticles on the encapsulation efficiency, antioxidant activity and release characteristics of curcumin.

RESULTS

The nanoparticles were formed through electrostatic interactions, hydrogen bonds and hydrophobic interactions between the proteins and HSSP. A temperature of 50 °C was more favorable for generating compact and small-sized nanoparticles, which could effectively improve the encapsulation efficiency and functional properties. Moreover, compared to other pectin used in the study, the nanoparticles prepared with HSSP showed the best functionality with a particle size of 234.28 ± 0.85 nm, encapsulation rate of 90.22 ± 0.54%, free radical scavenging rate of 78.97% and strongest protective capacity in simulated gastric fluid and intestinal release effect.

CONCLUSION

Zein-sodium caseinate-HSSP is effective for encapsulating and delivering hydrophobic bioactive substances such as curcumin, which has potential applications in the functional food and pharmaceutical industries. © 2024 Society of Chemical Industry.

Efficacy of almond gum for coacervation with whey protein isolate- optimization, functionality and characterization: A comparison with high-methoxyl pectin

Complex coacervates of whey protein isolate (WPI) and two polysaccharides (almond gum (AG) and high methoxyl pectin (HMP)) under the different pHs (2.5-6.0) and biopolymer mass ratios (1:1-6:1) were prepared to achieve the maximum coacervate yield (CY). The optimum pH and mixing ratio to obtain the maximum CY of WPI-AG (75.93 %) and WPI-HMP (53.0 %) coacervates were 4.3 and 2:1, and 3.5 and 3:1, respectively. Although higher serum layers in emulsions stabilized by WPI-AG/HMP coacervates were detected at the 90 °C, remarkable heat stability under processing temperatures was obtained in ex-situ emulsions with both complex coacervates. Significantly more cold-storage and ionic stabilities were observed for emulsions formulated with WPI-AG than WPI-HMP. Peak shifts in FTIR spectra in the WPI-AG coacervate compared to the individual WPI and AG biopolymers revealed strong electrostatic interactions between these biopolymers. The absence of crystalline peaks for AG and HMP in X-ray diffraction (XRD) spectra confirmed the complexation of AG and HMP with WPI. Thermogravimetric and microstructural analyses showed that porous, loose mesh-like WPI-AG coacervates had superior thermal stability and structural integrity compared to WPI-HMP coacervates and individual biopolymers, which evidenced a more gradual weight loss pattern. WPI-AG coacervates would be promising for efficient emulsion-based delivery systems.

Insight into the improvement mechanism of gel properties of pea protein isolate based on the synergistic effect of cellulose nanocrystals and calcium ions

Here, the influence and potential mechanism by which cellulose nanocrystals (CNC) collaborated with Ca2+ enhancing the heat-induced gelation of pea protein isolate (PPI) were investigated. It was found that the combination of 0.45% CNC and 15 mM Ca2+ synergistically increased the gel strength (from 14.18 to 65.42 g) and viscoelasticity of PPI while decreased the water holding capacity. The improved particle size, turbidity, and thermostability as well as the reduced solubility, crystallinity, and gel porosity were observed in CNC/CaCl2 composite system. CNC fragments bind to specific amino acids in 11S legumin and 7S vicilin mainly through hydrogen bonding and van der Waals forces. Moreover, changes in the protein secondary structure and enhancement of the molecular interaction induced by CNC and Ca2+ could favor the robust gel network. The results will provide a new perspective on the functional regulation of pea protein and the creation of pea protein gel-based food.

Effect of pectin structure on the in vitro bioaccessibility of carotenoids in simulated juice model

The impact of pectin structure on carotenoid bioaccessibility is still uncertain. This study aims to investigate how the different pectic polymers affected the bioaccessibility of carotenoids in a simulated juice model during static in vitro digestion. This study includes homogalacturonan (HG), which is a linear pectic polymer, rhamnogalacturonan-I (RG-I), which is a branched pectic polymer, and rhamnogalacturonan (RG), which is a diverse pectic polymer rich in RG-I, rhamnogalacturonan-II (RG-II), and xylogalacturonan domains. Juice models without pectin had the highest carotenoid bioaccessibility, suggesting pectin has negative effects on carotenoid bioaccessibility. During the intestinal phase, systems with HG showed the highest viscosity, followed by systems with RG and systems with RG-I. Systems with RG-I had lower carotenoid bioaccessibility than systems with HG and RG-II. Both the percentage of RG-I and the average side chain length of RG-I had negative correlations with carotenoid bioaccessibility. RG-I side chains with more arabinose and/or galactose might cause lower carotenoid bioaccessibility in this juice model system. This study offers valuable insights into the relationship between pectin structure and carotenoid bioaccessibility in a simulated juice model, highlighting the importance of considering pectin composition for maximizing carotenoid bioaccessibility and potential health benefits in fruit-based beverages.

Rice proteins - Gum arabic coacervates: Effect of pH and polysaccharide concentration in oil-in-water emulsion stability

In the context of replacing animal proteins in food matrices, rice proteins (RP) become promised because they come from an abundant plant source, are hypoallergenic, and have high digestibility and nutritional value. However, commercial protein isolates obtained by spray drying have low solubility and poor functionality, especially in their isoelectric point. One way to modify these properties is through interaction with polysaccharides, such as gum arabic (GA). Therefore, this work aims to evaluate the effects of pH and GA concentration on the interaction and emulsifying activity of RP:GA coacervates. First, the effects of pH (2.5 to 7.0) and GA concentrations (0.2 to 1.0 wt%, giving rise to RP:GA mass ratios of 1:0.2 to 1:1.0) in RP:GA blends were evaluated. The results demonstrated that biopolymers present opposite net charges at pH between 2.5 and 4.0. At pH 3.0, insoluble coacervates with complete charge neutralization were formed by electrostatic interactions, while at pH 5.0 it was observed that the presence of GA prevented the RP massive aggregation. Second, selected blends with 0.4 or 1.0 wt% of GA (RP:GA mass ratios of 1:0.4 or 1:1.0) at pH 3.0 or 5.0 were tested for their ability to stabilize oil-in-water emulsions. The emulsions were characterized for 21 days. It was observed that the GA increased the stability of RP emulsions, regardless of the pH and polysaccharide concentration. Taken together, our results show that it is possible to combine RP and GA to improve the emulsifying properties of these plant proteins at pH conditions close to their isoelectric point, expanding the possibility of implementation in food systems.

Simple and complex coacervation in systems involving plant proteins

Plant-based foods are gaining popularity as alternatives to meat and dairy products due to sustainability and health concerns. As a consequence, there is a renewed interest in the phase behaviour of plant proteins and of mixtures of plant proteins and polysaccharides, in particular in the cases where coacervation is found to occur, i.e., liquid-liquid phase separation (LLPS) into two phases, one of which is rich in biopolymers and one of which is poor in biopolymer. Here we review recent research into both simple and complex coacervation in systems involving plant proteins, and their applications in food- as well as other technologies, such as microencapsulation, microgel production, adhesives, biopolymer films, and more.

Improved emulsifying properties of water-soluble myofibrillar proteins at acidic pH conditions: Emphasizing pH-regulated electrostatic interactions with chitosan

Water-soluble muscle protein with enhanced functionalities has attracted great interest for low-salt food design. Electrostatic interactions of chitosan (CS) with myofibrillar proteins (MP) in water-aqueous solution at acidic pHs (4.0-6.5) were investigated, and how pH regulated complex formation, microstructures, conformation changes, and emulsifying capacity was systematically explored. At pH 4.0-4.5, MP and CS were positively charged and displayed a co-soluble system, exhibiting small particles and high solubility. When the pH increased to near the isoelectric point (pI) of MP (pH 5.0-6.0), electrostatic interactions largely inhibited the aggregation of MP by forming smaller particle complexes. The flexible structures and improved amphiphilic properties promoted protein absorption at the oil-water interface, further improving the emulsion stability. When the pH increased to 6.5, large aggregates were formed causing poor functionalities. This study could provide great insights to further exploit meat-protein-based low-salt functional foods in novel food design.

Interaction mechanisms of peanut protein isolate and high methoxyl pectin with ultrasound treatment: The effect of ultrasound parameters, biopolymer ratio, and pH

Ultrasound could effectively change molecular structure of proteins, polysaccharides, and their interactions, and was used to treat the peanut protein isolate-high methoxy pectin (PPI-HMP) complexes in this study. Effects of different ultrasound parameters, PPI-HMP mixing ratio (40:1-5:2), and pH (2.0-8.0) on the PPI-HMP interactions were investigated. Turbidity, solution appearance, and Zeta-potential analysis revealed an electrostatic interaction between PPI and HMP from pH 2.0 to pH 6.0. Ultrasound changed the tertiary structure conformation of PPI according to the surface hydrophobicity analysis. Increased ultrasound power density and pH broke the hydrogen bonds between the complexes according to Fourier transform infrared spectroscopy analysis. Apparent viscosity and confocal laser scanning microscopy analysis showed that appropriate ultrasound treatment (5.43 W/cm3, 25 min, 25 °C) reduced the viscosity of the complexes, and enhanced the electrostatic and hydrophobic interactions between PPI and HMP. These findings will contribute to the application of PPI-HMP complexes in the food industry.

Encapsulating vitamins C and E using food-grade soy protein isolate and pectin particles as carrier: Insights on the vitamin additive antioxidant effects

Functional factors show additive effects in the same nutraceutical food. In this study, a core-shell structure based on soy protein isolate (SPI) and pectin was constructed as a delivery system for vitamins C and E under neutral (pH 7.0) and acidic environment (pH 4.0). The SPI-vitamin-pectin complex formed at pH 4.0 showed larger particle size, higher turbidity, lower fluorescence intensity, and higher vitamin E encapsulation efficiency than those formed at pH 7.0. Also, the addition of vitamin C significantly enhanced the vitamin E encapsulation efficiency in the particles. Furthermore, the antioxidant properties of DPPH, ABTS, and hydroxyl radicals were increased by the addition of vitamin C, maximum values of 77%, 82%, and 65%, suggesting that vitamins C and E have additive antioxidant effects. These findings proposed a simple, structured protein-polysaccharide-based food-grade delivery system, which could serve as the basis for the design of products having multiple functional factors.

Improvement of functional characteristics of Hypophthalmichthys molitrix protein by modification with chitosan oligosaccharide

In the food processing field, it is very often that fish proteins are denatured affecting the nutritional value of the product which is vital to be solved. By using appropriate sugar donors for glycosylation with protein, improving the stability and emulsification properties of fish proteins can be achieved. This research looks into the impacts of enzymatic chitosan oligosaccharide (CO) at various concentration (0.15%, 0.30%, 0.45%, 0.60%, w/v) upon the molecular makeup and function of silver carp myofibrillar protein (MP) in an attempt to comprehend the impact of electrostatic binding among MP as well as CO on protein conformation. Analysis was done on the impact of various CO concentrations upon MP's secondary structure, conformational changes, and functional characteristics. Twelve sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) assays were implemented to monitor MP; Fourier transform infrared spectroscopy, endogenous fluorescence spectroscopy, and UV absorption spectra were carried out to investigate the influence of CO on MP; Particle size distribution, emulsifying activity index (EAI), solubility, turbidity, sulfhydryl content, carbonyl content, foaming capacity, surface hydrophobicity, emulsifying stability index (ESI), and foam persistence were all investigated. In addition, we used dynamic light scattering, scanning electron microscope, and atomic force microscope to analyze myosin (MO) and 0.60% CO-MO complex. The results demonstrated that CO and MP form complexes through hydrogen bonding and electrostatic interactions. CO modification not only delayed the oxidation of MP but also promoted MP to show better solubility, foaming, and foaming stability. In addition, CO modified myosin particle size decreased, reducing myosin's roughness and making myosin's structure more compact. To sum up, molecular interaction could change functional characteristics, and products with special properties could be developed after modification with chitosan oligosaccharide.

Orange Pomace and Peel Extraction Processes towards Sustainable Utilization: A Short Review

More than 58 million metric tonnes of oranges were produced in 2021, and the peels, which account for around one-fifth of the fruit weight, are often discarded as waste in the orange juice industry. Orange pomace and peels as wastes are used as a sustainable raw material to make valuable products for nutraceuticals. The orange peels and pomace contain pectin, phenolics, and limonene, which have been linked to various health benefits. Various green extraction methods, including supercritical carbon dioxide (ScCO₂) extraction, subcritical water extraction (SWE), ultrasound-assisted extraction (UAE), and microwave-assisted extraction (MAE), are applied to valorize the orange peels and pomace. Therefore, this short review will give insight into the valorization of orange peels/pomace extraction using different extraction methods for health and wellness. This review extracts information from articles written in English and published from 2004 to 2022. The review also discusses orange production, bioactive compounds in orange peels/pomaces, green extractions, and potential uses in the food industry. Based on this review, the valorization of orange peels and pomaces can be carried out using green extraction methods with high quantities and qualities of extracts. Therefore, the extract can be used for health and wellness products.

Encapsulation of Vitamin B12 by Complex Coacervation of Whey Protein Concentrate-Pectin; Optimization and Characterization

Vitamin B12 (VB12) is one of the essential vitamins for the body, which is sensitive to light, heat, oxidizing agents, and acidic and alkaline substances. Therefore, the encapsulation of VB12 can be one of the ways to protect it against processing and environmental conditions in food. In this work, the influence of pectin concentration (0.5−1% w/v), whey protein concentrate (WPC) level (4−8% w/v) and pH (3−9) on some properties of VB12-loaded pectin−WPC complex carriers was investigated by response surface methodology (RSM). The findings showed that under optimum conditions (1:6.47, pectin:WPC and pH = 6.6), the encapsulation efficiency (EE), stability, viscosity, particle size and solubility of complex carriers were 80.71%, 85.38%, 39.58 mPa·s, 7.07 µm and 65.86%, respectively. Additionally, the formation of complex coacervate was confirmed by Fourier-transform infrared (FTIR) spectroscopy and atomic force microscopy (AFM). In addition, it was revealed that the most important factor in VB12 encapsulation was pH; at a pH < isoelectric point of WPC (pH = 3), in comparison with higher pH values (6 and 9), a stronger complex was formed between pectin and WPC, which led to an increase in EE, lightness parameter, particle size and water activity, as well as a decrease in the zeta-potential and porosity of complex carriers.

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.

Production of Plant-Based Seafood: Scallop Analogs Formed by Enzymatic Gelation of Pea Protein-Pectin Mixtures

This study investigated the possibility of using a phase separation, mixing, and enzymatic gelation approach to construct seafood analogs from plant protein-polysaccharide mixtures with properties mimicking real seafood. Heat-denatured pea protein (10%, w/w) and pectin (0-1%, w/w) were mixed to produce phase separated biopolymer blends. These blends were then subjected to mild shearing (350 rpm) to obtain fiber-like structures, which were then placed in molds and set by gelling the pea proteins using transglutaminase (2%, w/w). The appearance, texture, and cooking properties of the resulting scallop analogs were characterized and compared to those of real scallop. The presence of the pectin promoted the formation of a honeycomb structure in the scallop analogs, and microscopic orientation of the proteins was observed in the plane parallel to the applied shear flow. Lower pectin concentrations (0.5%, w/w) led to stronger gels with better water holding capacity than higher ones (1.0%, w/w). The appearance and texture of the plant-based scallop analogs were like those of real scallop after grilling, indicating the potential of using this soft matter physics approach to create plant-based seafood analogs. One of the main advantages of this method is that it does not require any expensive dedicated equipment, such as an extruder or shear cell technology, which may increase its commercial viability.

Pickering emulsions stabilized by pea protein isolate-chitosan nanoparticles: fabrication, characterization and delivery EPA for digestion in vitro and in vivo

The work aimed to prepare pea protein isolate-chitosan (PPI-CS) nanoparticles, fabricate PPI-CS nanoparticles stabilized Pickering emulsions (PPI-CS Pickering emulsions) and deliver EPA for digestion in vitro and in vivo. The nanoparticles were characterized by scanning electron microscopy (SEM), and PPI-CS Pickering emulsions were characterized by physicochemical and rheological properties. The results showed that the size of PPI-CS nanoparticles was 194.22 ± 0.45 nm. Rheological measurement showed that the PPI-CS Pickering emulsions possessed a gel-like network. EPA encapsulated Pickering emulsions (EPA-PE, φ = 0.6) exhibited a high retention rate (93%) during storage and performed a lower release rate compared with EPA-PE (φ = 0.4) in vitro digestion. The area under the curve of EPA concentration of EPA-PE group and EPA-emulsions (EPA-Em) group was 1.71 and 1.48, respectively. It demonstrated that PPI-CS Pickering emulsions provided the possibility to deliver EPA for digestive absorption.

Impact of rutin on the foaming properties of soybean protein: Formation and characterization of flavonoid-protein complexes

The aims of present study were to determine the impact of rutin complexation on the ability of soybean protein isolates (SPI) to form and stabilize foams and its mechanism. At pH 7.0, the foaming capacity and foaming stability of the rutin-SPI complexes (28.33% and 14.22%) was appreciably changed when compared with that of SPI alone (19.64% and 32.95%). The improvement in foaming properties was mainly attributed to decrease gas bubble size and increase interfacial thickness as suggested by light microscopy analysis. UV-visible spectroscopy showed that the absorption peak of the SPI was increased and red shifted after complexation with rutin. ITC confirmed that there was an interaction between rutin and SPI. This interaction was hydrophobic interaction and the binding process was entropy driven. This study shows that the foaming properties of plant-based proteins can be improved by forming complexes with flavonoids, which may be useful for foaming agents in foods.

Advances of plant-based structured food delivery systems on the in vitro digestibility of bioactive compounds

Food researchers are currently showing a growing interest in in vitro digestibility studies due to their importance for obtaining food products with health benefits and ensuring a balanced nutrient intake. Various bioactive food compounds are sensitive to the digestion process, which results in a lower bioavailability in the gut. The main objective of structured food delivery systems is to promote the controlled release of these compounds at the desired time/place, in addition to protecting them during digestion processes. This review provides an overview of the influence of structured delivery systems on the in vitro digestive behavior. The main delivery systems are summarized, the pros and cons of different structures are outlined, and examples of several studies that optimized the use of these structured systems are provided. In addition, we have reviewed the use of plant-based systems, which have been of interest to food researchers and the food industry because of their health benefits, improved sustainability as well as being an alternative for vegetarian, vegan and consumers suffering from food allergies. In this context, the review provides new insights and comprehensive knowledge regarding the influence of plant-based structured systems on the digestibility of encapsulated compounds and proteins/polysaccharides used in the encapsulation process.

Non-animal proteins as cutting-edge ingredients to reformulate animal-free foodstuffs: Present status and future perspectives

Consumer interest in protein rich diets is increasing, with more attention being paid to the protein source. Despite the occurrence of animal proteins in the human diet, non-animal proteins are gaining popularity around the world due to their health benefits, environmental sustainability, and ethical merit. These sources of protein qualify for vegan, vegetarian, and flexitarian diets. Non-animal proteins are versatile, derived mainly from cereals, vegetables, pulses, algae (seaweed and microalgae), fungi, and bacteria. This review's intent is to analyze the current and future direction of research and innovation in non-animal proteins, and to elucidate the extent (limitations and opportunities) of their applications in food and beverage industries. Prior knowledge provided relevant information on protein features (processing, structure, and techno-functionality) with particular focus on those derived from soy and wheat. In the current food landscape, beyond conventionally used plant sources, other plant proteins are gaining traction as alternative ingredients to formulate animal-free foodstuffs (e.g., meat alternatives, beverages, baked products, snack foods, and others). Microbial proteins derived from fungi and algae are also food ingredients of interest due to their high protein quantity and quality, however there is no commercial food application for bacterial protein yet. In the future, key points to consider are the importance of strain/variety selection, advances in extraction technologies, toxicity assessment, and how this source can be used to create food products for personalized nutrition.

Complex coacervation of pea albumin-pectin and ovalbumin-pectin assessed by isothermal titration calorimeter and turbidimetry

BACKGROUND

This study investigates the complexation of a pea albumin-rich fraction and ovalbumin with pectin of different degrees of esterification (DE) and blockiness (DB) as a function of pH and biopolymer mixing ratio by turbidimetric titration and isothermal titration calorimetry (ITC).

RESULTS

Turbidimetric analysis found maximum complexation occurred at a mixing ratio of 4:1 for pea albumin with high methoxy pectin, 8:1 for pea albumin with low methoxy pectin, and 8:1 for ovalbumin with low methoxy pectin. In the case of ovalbumin with high methoxy pectin, interactions were very weak. The pectin with high levels of esterification and blockiness displayed greater interactions with the pea albumin in both turbidimetry and ITC. However, low methoxy pectin imparted better interactions with ovalbumin and displayed higher optical density values than high methoxy pectin.

CONCLUSIONS

The current study indicated that the different thermodynamic parameters of PA-pectin complexes can be tuned by controlling the structural characteristics (DB, DE, and d-galacturonic acid) of the pectin. © 2020 Society of Chemical Industry.