Functional Performance of Plant Proteins

Effects of proteolysis pretreatment on the formation, structural changes and emulsifying properties of rice glutelin amyloid-like fibrils

Enzymatic hydrolysis prior to fibrillation can improve the formation capacity of food protein fibrils, which further affects their functional properties. In this study, the effects of proteolysis pretreatment with trypsin on the formation, structural changes and emulsifying properties of rice glutelin (RG) fibrils were investigated. The results showed that the formation of protein fibrils was confirmed by Thioflavin T fluorescence spectra, and the fibril formation capacity was enhanced by trypsin proteolysis pretreatment. The fibrils derived from the enzymatically modified rice glutelin (E-RG) had more β-sheet structures (58.20 %). Hydrogen bonds and hydrophobic interactions were mainly involved in the formation of fibrils. More and more flexible fibrils were observed during the E-RG fibrillation. In addition, the emulsifying activity (21.68 m2/g), stability (26.84 min) and apparent viscosity of the E-RG fibrils were improved. Hence, these findings can provide a reference for broadening the application of rice glutelin fibrils in food processing.

From seed to solution: Enhancing techno-functionality and digestibility of pumpkin seed protein isolate through high-intensity ultrasound, high-pressure processing, and pH-shifting

This study investigated a novel approach combining pH shifting with high-intensity ultrasound (HIUS) or high-pressure processing (HPP) to enhance pumpkin seed protein isolate (PSPI) properties. PSPI, derived from defatted pumpkin seed flour, was treated using pH shifting, HPP, HIUS, or their combinations. The pH shifting + HIUS treatment yielded the most significant improvements, including enhanced protein solubility (69.1 %), surface hydrophobicity (251.1), free sulfhydryl content (5.88 μmol/g), antioxidant activity (17.2 %), and total phenolic content (3.1 mg catechin/g). A heatmap analysis showed that this combination achieved the most substantial structural changes and functionality enhancements, followed by pH shifting + HPP. In comparison, pH shifting alone induced moderate changes, and individual treatments like HIUS or HPP were less effective than their combinations. Untreated PSPI, used as a baseline, exhibited minimal structural changes, larger particle size, lower solubility, and less desirable functionality. These findings highlight the superiority of combined treatments, particularly pH shifting + HIUS, in improving the properties and potential applications of PSPI.

FTIR Spectroscopic Analysis of Plant Proteins and Correlation with Functional Properties

BACKGROUND

The development of plant-based products faces challenges like raw material standardization and time-consuming functionality measurements. FTIR spectroscopy provides a quick, non-destructive way to analyze protein molecular characteristics.

OBJECTIVE

This study explored the classification capability of FTIR in analyzing five plant protein isolates-soy, mung bean, pea, fava bean, and lentil-and assessed its predictive ability for functional property measurement such as water absorption capacity (WAC), oil absorption capacity (OAC), solubility (SOL), foaming, and emulsification.

METHODS

Functional properties were calculated using traditional methods of measurements. Principal component analysis (PCA) and partial least-squares (PLS) regression analysis were used to study FTIR spectra and their correlation with functional properties.

RESULTS

PCA revealed distinct clusters for each protein source based on their FTIR spectra, indicating molecular differences. WAC and OAC prediction models showed strong correlations, with prediction correlation coefficients (Rp) of more than 0.99 and cross-validation correlation coefficients (Rcv) ranging from 0.85 to 0.92. Models for SOL and emulsifying activity index (EAI) display promising potential. Moreover, WAC and OAC predictions exhibited robust results with protein blends of various ratios. The expanded WAC model predicted with an Rp of 0.99 and an Rcv of 0.95, while the expanded OAC model had an Rp of 0.99 and an Rcv of 0.84.

CONCLUSION

The results underscore FTIR has the potential to identify plant proteins, aiding in raw material verification and QC as well as being an alternative to analyzing functional properties of plant proteins.

HIGHLIGHTS

This study demonstrates the potential of FTIR spectroscopy as a rapid, non-destructive tool for plant protein characterization and functional property prediction. FTIR successfully distinguished five plant protein isolates-soy, mung bean, pea, fava bean, and lentil-through PCA-based spectral clustering. Strong predictive models for water and oil absorption capacities (WAC and OAC) were developed, with prediction correlation coefficients (Rp) values exceeding 0.99 and cross-validation correlation coefficients (Rcv) ranging from 0.84 to 0.95. Functional property predictions for solubility (SOL) and emulsifying activity index (EAI) showed promising potential. These findings highlight FTIR's capability for protein classification, raw material verification, and rapid functional property assessment in quality control applications.

Effects of high-intensity ultrasound, high-pressure processing, and their combination with pH-shifting on the techno-functionality and digestibility of melon seed protein isolate

This study presents a novel approach to improving the functional and nutritional properties of melon seed protein isolate (MSPI) through the combination of pH shifting with high-intensity ultrasound (HIUS) or high-pressure processing (HPP). MSPI, extracted from defatted melon seed flour (DMSF), was treated using five methods: pH shifting, HIUS, HPP, pH shifting + HIUS, and pH shifting + HPP. Among these, pH shifting + HIUS demonstrated the most significant improvements, including enhanced protein solubility (78.1 %), free sulfhydryl content (6.24 μmol/g), surface hydrophobicity (268.1), antioxidant activity (19.8 %), and total phenolic content (3.4 mg catechin/g dry weight). These enhancements translated into improved functional properties, such as foam stability, oil and water absorption capacity, and gel-forming ability, along with a reduction in particle size (40.3 nm) and viscosity. Additionally, this treatment yielded the highest denaturation temperature (94.4 °C), indicating improved protein stability, and increased protein digestibility (95.5 %). Microscopically, the treatment caused significant structural changes, creating large voids, cracks, and irregular surfaces that enhance protein reactivity. FTIR analysis revealed a shift toward higher wavenumbers, suggesting disruption of intermolecular and intramolecular bonds, increasing reactive sites on the protein. The results highlight the potential of combining pH shifting with HIUS or HPP as an innovative strategy for enhancing the techno-functional and nutritional properties of plant proteins. This method offers promising applications in developing high-performance, plant-based protein ingredients for the food industry, aligning with the increasing demand for sustainable and functional protein sources.

Effect of Ultrasound Time on Structural and Gelling Properties of Pea, Lupin, and Rice Proteins

Plant proteins are garnering interest due to the growing demand for plant-based products, but their functionality in gel-based foods remains limited. Ultrasound (US) technology may improve the technological properties of proteins. Thus, the effect of US treatment time (0-15 min) on the structure and gelling properties of pea, lupin, and rice proteins was evaluated. The results showed that the whiteness (~60%) of all freeze-dried proteins remained unchanged (p > 0.05), regardless of the US time. However, FT-IR analysis revealed progressive reductions in α-helix and β-sheet for pea and lupin proteins (~50%) with US time, indicating partial unfolding. In addition, microstructure analysis showed an ~80% reduction in aggregate size for these proteins, while rice protein exhibited minimal changes. Conversely, weak gels were formed with pea and lupin proteins treated after 5 and 10 min of US, respectively, whereas rice protein did not form gels. Furthermore, US treatment time significantly increased (p < 0.05) the mechanical moduli, resulting in more structured gels after longer treatment times (tan δ ~0.3 at 15 min of US). These findings suggest that US treatment enhances the gelling properties of pea and lupin proteins, making them more suitable for plant-based food applications such as yogurt or desserts.

Techno-functionality of jack bean (Canavalia ensiformis) protein concentrate: a comparative study with soy and pea proteins

BACKGROUND

With the growing human awareness of the environmental and animal stress caused by the meat industry, the consumption of plant-based products has expanded. Plant proteins have gained market prominence due to their sustainable origin, economic value and health benefits. Well-established plant proteins in the market, such as those of soy and pea, have various applications as ingredients in the food industry. However, given the wide variety of protein sources, it is necessary to conduct studies on the chemical and techno-functional characterization of other raw materials to further diversify their properties. In this context, the present study introduces jack bean protein concentrate (JBPC) as a potential alternative to proteins already established in the market. Techno-functional properties such as surface hydrophobicity, solubility, zeta potential, water- and oil-holding capacity, foam capacity and stability, emulsion stability and gel formation and rheology were analyzed.

RESULTS

The protein content obtained from the extraction of the JBPC was 73 g (100 g)-1 on a dry weight basis, with an extraction yield of approximately 10% (w/w). Least gelation concentration for JBPC was 20%. JBPC exhibited a predominantly hydrophobic nature, with good oil retention capacity and emulsion and foam stabilization properties. The structure of JBPC was more linear, stable and rigid, which primarily influenced gel stiffness.

CONCLUSION

Based on the study of techno-functional properties, JBPC proved to be an excellent alternative to soy protein isolate and pea protein concentrate in various applications, with potential for becoming an innovative ingredient in the food industry. © 2025 Society of Chemical Industry.

Insights from traditional fermented legumes towards the innovation of modern plant-based meat analogues

There has been a major growth in the development of plant-based meat alternatives (PBMA) in recent years. However, current PBMA often contain ultra processed ingredients and numerous additives to be able to mimic animal-based meat (ABM) including the meaty (umami) flavour, characteristic firm/chewy structure and juicy mouthfeel. In this review, the potential of ancient fermentation techniques as a minimally processed alternative to ABM and current PBMA are explored. Fermented foods including tempeh, natto, dawadawa and ugba are naturally high in protein and umami flavours. The nutritional, aroma, flavour and techno-functional properties are provided and discussed in the context of ABM and PBMA. The fermented foods have potential to be used as whole foods ingredients, or their constituents can be used as ingredients in plant-based foods. Particularly the umami flavours and high protein content combined with the naturally occurring high water holding capacity (WHC), solubility and other material properties make fermented legume foods suitable candidates for use in high-protein plant-based foods. Understanding the sensory characteristics and material properties generated during legume fermentation and their similarities to ABM can aid in stimulating innovations in food technology to obtain a new generation of less-processed PBMA with limited additives.

Ultrasound-induced modification of pea pod protein concentrate

Agricultural by-products have emerged as valuable resources for the sustainable production of high-quality food ingredients. Ultrasound, a novel and environmentally friendly technology, is an effective physical method for solvent-free protein modifications. This study explores the conversion of pea pods as an agricultural by-product into value-added protein-based food ingredients with multifunctional properties enhanced by high-intensity ultrasound (US). Pea pod protein concentrate in the native form (PPPC-N) obtained by alkaline extraction/isoelectric precipitation was subjected to ultrasound-induced protein modification using response surface methodology at varying amplitude (40-80 %), time (2-20 min), and protein concentration (1-5 % w/v). The US process parameters were separately optimized based on maximum solubility, emulsification, and antioxidant activity. Protein concentrates were characterized at optimal conditions (80 % amplitude, 11 min, and 1 % protein; the desirability of 0.964) based on the maximum emulsification. The optimized PPPC by US (PPPC-US) exhibited a superior solubility performance compared to PPPC-N in the pH range of 2.0-9.0. The optimal US treatment enhanced the emulsifying attributes and foaming capacity of PPPC-N with an increase of 49 %. Moreover, oil binding capacity significantly increased while water binding capacity and foam stability decreased. Developing functional ingredients from pea pod proteins can open new possibilities in formulating innovative products.

Plant protein-based Pickering emulsion for the encapsulation and delivery of fat-soluble vitamins: A systematic review

Vitamin deficiencies pose a significant global health challenge, leading to various health issues and economic burdens. These challenges arise with the delivery of fat-soluble vitamin (FSV) due to its poor stability against the environmental stimuli. The commercial fortification methods such as Pickering emulsion (PE), hydrogel and others offer a potential solution over the limitations of conventional vitamin delivery methods (degradation and poor bioavailability). PE stabilized by solid plant protein particles, have emerged as a promising approach for encapsulation and delivery of oil-soluble vitamins (A, D, E, and K). Plant proteins, with their amphiphilic nature and nutritional benefits, are particularly well-suited as a stabilizer for PE. Plant protein-based PE enhances protection of vitamins against the environmental stimuli and enhances the delivery efficiency of oil-soluble vitamins. Factors such as particle size, concentration, and oil type also influence the stability, encapsulation efficiency, and bio-accessibility of fat-soluble vitamins in PE. Hence, the present review explores the impact of various factors on the stability and bio-accessibility of fat-soluble vitamins (A, D and E) and also emphasizing the role of particle size and concentration of stabilizer in controlling release rates of vitamin encapsulated PE. The review also highlights the application of plant protein-based PEs in various food products including nutrient fortification, functional foods, and 3D food printing.

Unveiling the potential of bean proteins: Extraction methods, functional and structural properties, modification techniques, physiological benefits, and diverse food applications

Bean proteins, known for their sustainability, versatility, and high nutritional value, represent a valuable yet underutilized resource, receiving less industrial attention compared to soy and pea proteins. This review examines the structural and molecular characteristics, functional properties, amino acid composition, nutritional value, antinutritional factors, and digestibility of bean proteins. Their applications in various food systems, including baked goods, juice and milk substitutes, meat alternatives, edible coatings, and 3D printing inks, are discussed. The physiological benefits of bean proteins, such as antidiabetic, cardioprotective, antioxidant, and neuroprotective effects, are also presented, highlighting their potential for promoting well-being. Our review emphasizes the diversity of bean proteins and highlights ultrasound as the most effective extraction method among available techniques. Beyond their physiological benefits, bean proteins significantly enhance the structural, technological, and nutritional properties of food systems. The functionality can be further improved through various modification techniques, thereby expanding their applicability in the food industry. While studies have explored the impact of bean protein structure on their nutritional and functional properties, further research is needed to investigate advanced modification techniques and the structure-function relationship. This will enhance the utilization of bean proteins in innovative and sustainable food applications.

Effect of Extrusion Conditions on the Characteristics of Texturized Vegetable Protein from a Faba Bean Protein Mix and Its Application in Vegan and Hybrid Burgers

The aim of this study was to produce texturized vegetable proteins (TVPs) from faba bean protein via low-moisture extrusion. The effect of extrusion variables including temperature (110, 125, and 140 °C at the die), feed moisture content (30, 35, and 40%), and screw speed (200, 300, and 400 rpm) on the TVP properties were investigated. An increase in feed moisture content or extruder temperature reduced the specific mechanical energy and torque by 40-45% during extrusion. An increase in feed moisture created TVPs with lower bulk densities and rehydration ratios while an increase in extruder temperature or screw speed increased the bulk density of the TVPs. An increase in screw speed also caused a decrease in the water holding capacity of the milled TVP flours. The TVP flours had a 33-70% higher oil holding capacity than the raw material. The texture profile showed that an increase in feed moisture influenced TVP hardness, gumminess, and chewiness with higher values compared to the treatments with lower moisture contents. Springiness, cohesiveness, and resilience were more affected by a change in screw speed with higher values at 200 rpm. The best parameters were selected (125 °C, 40% MC, 300 rpm) to produce TVP to use as a partial (hybrid burger) and complete (vegan burger) replacement of beef in a burger patty. The replacement of 25% beef with TVPs in a hybrid burger increased the cooking yield and moisture retention and decreased the thickness and diameter change compared to the beef burger without TVPs. In a vegan formulation, the faba bean TVP burger had lower cooking yield and moisture retention than commercial products.

Sustainable protein concentrate from Cannabis sativa L. seeds: Green chemistry and new functional concentrates for the alternative protein industry

This research focused on developing a hemp protein concentrate through a potential sustainable method, with nutritional and industrial value for the emerging alternative protein industry. By response surface methodology, the optimal processing conditions (100% ethanol, 50°C, and 10% w/v solid-to-solvents ratio) resulted in a hemp protein concentrate with 68.61% ± 1.71% protein. The process had a protein yield value of 94.11% ± 4.45%, which aligns with current sustainable food processing trends and is an excellent value compared to traditional methods for hemp seeds. The concentrate met nutritional quality criteria for most examined parameters and showed positive results regarding essential amino acids absorption through in vitro digestion compared to nonessential amino acids. Furthermore, its techno-functional properties, particularly oil-holding capacity, emulsification properties, and gelling qualities achieved commercial standards. This research validates the potential for producing new protein concentrates from dehulled hemp seeds through an innovative green chemistry-based method. PRACTICAL APPLICATION: The research presents a method based on green chemistry for the obtention of hemp protein concentrate from hemp seeds. Hemp seeds are not considered a "novel food" according to the European Commission. Hemp protein concentrate had 95% protein yield and similar or better functional properties compared to commercial proteins. Thus, hemp protein is an important product for food industry applications.

Emerging alternative food protein sources: production process, quality parameters, and safety point of view

The rise in the global population has increased the demand for dietary food protein. Strategies to maximize agricultural and livestock outputs could strain land and freshwater supply and contribute to substantial negative environmental impacts. Consequently, there has been an emphasis on identifying alternative sources of edible proteins that are more sustainable, sustainable, ethical, and healthy. This review provides a critical report on future food protein sources including: plant, cultured meat, insect, and microbial, as alternative sources to traditional animal-based sources. The technical challenges associated with the production process of alternative protein sources are discussed. The most important quality parameters of alternative proteins, such as: protein composition and digestibility, allergenicity, functional and sensory attributes, and safety regulations have been documented. Lastly, future direction and conclusion have been made on future protein trends. However, further regulatory norms need to develop for safe consumption and distribution around the world.

Spray dried protein concentrates from white button and oyster mushrooms produced by ultrasound-assisted alkaline extraction and isoelectric precipitation

BACKGROUND

In the present study, the optimization of ultrasound-assisted alkaline extraction (UAAE) and isoelectric precipitation (IEP) was applied to white button (WBM) and oyster (OYM) mushroom flours to produce functional spray dried mushroom protein concentrates. Solid-to-liquid ratio (5-15% w/v), ultrasound power (0-900 W) and type of acid [HCl or acetic acid (AcOH)] were evaluated for their effect on the extraction and protein yields from mushroom flours submitted to UAAE-IEP protein extraction.

RESULTS

Prioritized conditions with maximized protein yield (5% w/v, 900 W, AcOH, for WBM; 5% w/v, 900 W, HCl for OYM) were used to produce spray dried protein concentrates from white button (WBM-PC) and oyster (OYM-PC) mushrooms with high solids recovery (62.3-65.8%). WBM-PC and OYM-PC had high protein content (5.19-5.81 g kg-1), in addition to remarkable foaming capacity (82.5-235.0%) and foam stability (7.0-162.5%), as well as antioxidant phenolics. Highly pH-dependent behavior was observed for solubility (> 90%, at pH 10) and emulsifying properties (emulsification activity index: > 50 m2 g-1, emulsion stability index: > 65%, at pH 10). UAAE-IEP followed by spray drying increased surface hydrophobicity and free sulfhydryl groups by up to 196.5% and 117.5%, respectively, which improved oil holding capacity (359.9-421.0%) and least gelation concentration (6.0-8.0%) of spray dried mushroom protein concentrates.

CONCLUSION

Overall, the present study showed that optimized UAAE-IEP coupled with spray drying is an efficient strategy to produce novel mushroom protein concentrates with enhanced functional attributes for multiple food applications. © 2024 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Ultrasound treatment on commercial pea protein isolates systems: Effect on structure, rheology and gelling properties

Pea protein has attracted great attention due to its capability to meet the growing requirements from consumers for desired nutrition and texture from plant protein. Hence, the current study aimed to investigate the effects of different ultrasonic treatment parameters (power and duration) on the gelling characteristics of commercial pea protein isolates (PPIc). The findings demonstrated that by manipulating the ultrasonic power and treatment duration, great enhancement of the solubility, adhesiveness and formation strength of PPIc gel can be realized. The reduction in particle size was positively correlated with higher power and longer treatment durations. Interestingly, no direct correlation between average particle size, solubility, turbidity, and ζ-potential was observed. Additionally, the ultrasound-modified PPIc in this study exhibited comparable characteristics to laboratory-prepared pea protein isolates, in terms of solubility, water-holding capacity, and gel strength. Overall, manipulating ultrasonic parameters presents a feasible method to customize the texture of pea-protein-based substitute.

Structure-property relationship of pea protein microgels as fat analogues in Pickering oil-in-water emulsions: effect of salt addition

BACKGROUND

The design of plant-based microgels provides a platform for food ingredients to enhance palatability and functionality. This work aimed to explore the modifying effect of salt addition (KCl) on the structure of pea protein microgel particles (PPI MPs), on the interfacial adsorption and characteristics of formed emulsions as fat analogues.

RESULTS

Salt addition (0-200 mmol L-1) promoted a structural transformation from α-helix to β-sheet, increased the surface hydrophobicity (from 1160.8 to 2280.7), and increased the contact angle (from 56.73° to 96.47°) of PPI MPs. The electrostatic shielding effect led to the tighter packing of MPs with irregular structures and lowered the adsorption energy barrier. Notably, salt-treated PPI MPs could adjust their adsorption state at the interface. The discernible adsorption of PPI MPs with 200 mmol L-1 salt addition that possessed enhanced anti-deformation ability dominated the interfacial stabilization, whereas a relatively rougher stretched continuous interfacial film formed after spreading and deformation of 0 mmol L-1 MPs. A tribological test suggested that emulsion stabilized by MPs at 0 (0.0053) and 80 mmol L-1 (0.0068) had similar friction coefficients to commercial mayonnaise (0.0058), whereas a higher salt concentration (200 mmol L-1) lowered its oral sensation due to the adsorption layer and enhanced the resistance to droplet coalescence during oral processing.

CONCLUSION

Salt could be a modifier to tune the structure of microgels, and further promote the formation and attributes of emulsions. This study would improve application attributes of PPI MPs in the design of realistic fat analogues. © 2024 Society of Chemical Industry.

Effect of Extraction Methods and Preheat Treatments on the Functional Properties of Pumpkin Seed Protein Concentrate

This study explores the effect of different extraction methods and preheat treatments in obtaining protein concentrate from pumpkin seed flour. The effects on the yield and functional properties of pumpkin seed protein concentrate (PSPC) were compared alongside microwave and conventional preheating methods using alkali, salt, and enzyme-assisted alkali extraction techniques. Analytical assessments included proximate analysis, soluble protein content, water solubility index (WSI), emulsification activity (EA) and stability (ES), foaming capacity (FC) and stability (FS), and antioxidant activity (AA). Hydration and structural analyses were performed via time-domain nuclear magnetic resonance (TD-NMR) Relaxometry and Fourier-Transform Infrared (FTIR) Spectroscopy. In addition, color measurements were performed to evaluate the visual quality of the samples. The alkali extraction method paired with microwave heating (MH-AE) significantly outperformed other techniques, with an extraction yield and protein content of approximately 55% and 77%, respectively. This study demonstrated the superior yield and functional properties of PSPC using MH-AE, opening opportunities for future research in optimizing plant-based protein extraction techniques.

Study on gastric digestion behavior of phytase-treated soybean protein: A semi-dynamic digestion method

The digestive characteristics of plant proteins are crucial for their nutritional value and utilization efficiency. In this study, an in vitro semi-dynamic digestion model was employed to investigate the gastric digestion process of soybean protein after treatment with phytase. The results found that phytase treatment reduced the phytate content in soybean proteins (22.83 ± 0.09 to 8.72 ± 0.07 mg/g), shifted its isoelectric point towards the alkaline range by 1 pH unit, and significantly improved its solubility at pH 4.0. Particularly for protein sample treated with phytase after acid precipitation, the formation of aggregates during digestion was weakened, resulting in a significantly higher digestion rate compared to untreated SPI, with digestion being at least 15 min faster than SPI. This study provides a strategy for preparing soybean protein with faster digestion and weaker clot-forming ability during digestion, which offers insights for the application of soybean protein in clinical nutrition products and specialized medical foods.

Elucidating the role of compositional and processing variables in tailoring the technological functionalities of plant protein ingredients

Although various plant protein (PP) ingredients are available on the market, their application in foods is not trivial, and food companies are struggling to identify PP ingredients fitting the intended use. To fill this gap, abundant literature has appeared but data are hardly comparable due to the absence of a recognized classification of PP ingredients accounting not only for protein purity but also for the process history, and of standardised protocols for technological functionality assessment. In this review, a comprehensive analysis of comparable literature data was thus carried out to elucidate the effect of composition and processing variables on PP technological functionalities. The review presents four sections describing: (i) the approach followed for the construction of a database of PP ingredient functionalities; (ii) the composition and processing factors relevant to PP ingredients; (iii) PP ingredient functional properties and methods used for their determination; (iv) the effect of composition and processing factors on PP ingredient functionalities. This analysis showed legume proteins to present the highest solubility and interfacial properties while pseudocereal ones the highest water-holding capacity. Although pure ingredients show higher functionalities, non-protein components could contribute to interfacial properties. Alkaline extraction, isoelectric precipitation and freeze-drying is the process mostly used in academic research to obtain PP ingredients. However, other extraction, purification, and drying methods can be properly combined, resulting in specific PP ingredient functionalities. Overall, this review highlights that, besides protein purity and source, knowledge of the processing history is required to select PP ingredients with desired functionalities.

Synergy of Analytical Characterization and Biocompatible Extractions for the Enhancement of High-Quality Biorefinery Products from Medicago sativa

This study presents the development of an analytical characterization strategy tailored to end products derived from an alfalfa (Medicago sativa)-based biorefinery with particular emphasis on protein concentrates and phenolic-enriched fractions. Our approach began with a comprehensive full-factorial experimental design aimed at optimizing the extraction process, taking care to design a biocompatible extraction protocol. Liquid chromatography with tandem mass spectrometry (LC-MS/MS) techniques were used to characterize the molecular profile of the extracts. In particular, the extracts showed a significant relative abundance of flavonoids and isoflavonoids in both their aglycone and glycosylated forms, in which antioxidant activity was evaluated. In addition, we elucidated the proteomic profiles of the protein concentrates. This proteomic characterization served as a valuable resource for understanding the differences between these end products, providing insights that can guide informed decisions about their potential applications.

Structure-functionality relationship and modification strategies of oat protein: Challenges and opportunities

The increasing preference for plant-based proteins over animal-derived equivalents has intensified research into alternative protein sources, with oats emerging as a noteworthy specialty crop due to their rich array of functional and bioactive components. Despite the growing interest, research into oat proteins remains in its early stages, particularly in understanding the structure-function relationship and modification strategies within food systems. Designing novel food products using oat protein presents both opportunities and challenges; the compact quaternary structure and high thermal stability of oat globulin limit its functionality in diverse applications. This review aims to detail the composition and structural characteristics of oat protein, highlighting the complex relationship between these structural traits and their functional properties. A significant focus is placed on innovative structural modification techniques that enable the cost-effective transformation of oat protein into a functional ingredient or base for new food product development.

Effects of Peptidase Treatment on Properties of Yeast Protein as an Alternative Protein Source

Yeast protein, high-quality and high-content microbial protein, can serve as alternative sources of protein. This study examined the structural and functional characteristics of yeast protein through enzymatic treatment using different ratios of alcalase (endo-type) and prozyme 2000P (exo-type) including 2:1 (A2P1), 1:1 (A1P1), and 1:2 (A1P2). After enzymatic hydrolysis, a significant increase in protein solubility from less than 3.1% in untreated proteins to around 16%, particularly at pH 2 or pH 12. Furthermore, a maximum degree of hydrolysis of over 85% was achieved after enzyme treatment. Among them, the highest value of 87.73% was achieved at yeast protein treated by A1P2. Scanning electron microscopy images revealed varied surface morphologies, with exhibiting an increased surface area, particularly after treatment using A2P1. Next, yeast protein treated with A2P1 also demonstrated a superior emulsion stability index (3364.17). However, the antioxidant capacity was higher in proteins treated with A1P2 (78.30%). In addition, the elevated levels of certain amino acids, specifically leucine, lysine, phenylalanine, valine, and arginine, thereby indicating an enhanced amino acid profile was observed. Overall, yeast proteins treated with complex enzymes exhibited improved functionality and potential for diverse food applications.

Characterization and Techno-Functional Properties of High Protein Walnut Flour from an Oil by-Product

A high protein walnut flour (HPWF) was obtained by defatting walnut flour (WF), which is a by-product of the oil industry. The objective of this study was the chemical and techno-functional characterization of HPWF. Composition, amino acid content, protein secondary structure, protein solubility and thermal transitions were measured. Besides, the techno-functional properties, emulsion activity and stability, and water holding and oil absorption capacities, of HPWF were evaluated. Also, the molecular mass of proteins under denaturing conditions and the microstructure of HPWF were evaluated by electrophoresis and confocal scanning laser microscopy, respectively. HPWF had 55.4% protein content and 21.5% total dietary fibre. In terms of HPWF amino acid composition, the limiting amino acids were the sulphurated cysteine and methionine. By FTIR analysis, the main secondary structures were β-sheet (49%) followed by α-helix (24%); both structures are considered to be ordered. Likewise, HPWF soluble proteins increased at basic pH and HPWF proteins were separated in 11 bands with molecular masses ranging from 97 kDa to 18 kDa by electrophoresis. With respect to techno-functional properties, HPWF presented good emulsion activity (51%) and high thermal emulsion stability (46%). In addition, HPWF retained 571% and 242% of water and oil by weight, respectively. Finally, the micrograph showed the predominance of protein structures and fibre fragments, and the presence of few lipids mostly trapped. These results showed that HPWF is an interesting source of plant-based proteins and walnut flour can be used to obtain high protein ingredients from non-traditional sources.

Recovery of keratin from feather meal: a new route to valorize an agro-industrial co-product

The valorization of agro-industrial by-products/co-products represents a sustainable pathway to produce high-value biomaterials. Feather meal is an agro-industrial co-product derived from clean and undecomposed poultry feathers processed under high heat and pressure that offers an economically viable and scalable alternative for keratin extraction compared to native feathers. This study explores the recovery of keratin from feather meal through an optimized alkaline hydrolysis process, achieving a yield of 20 wt.% at 15°C and 90 min of extraction by using 2 mol L-1 sodium hydroxide solution. A negative temperature dependence was observed in keratin extraction yield, suggesting the occurrence of thermal degradation at elevated temperatures. Protein analyses by different techniques confirmed the characteristic diffraction peaks, functional groups, and elemental composition (carbon, nitrogen, oxygen, and sulphur) of feather keratin. The extracted keratin presented a low molar mass of 9 kg mol-1. Considering the circular economy principles, this work proposes a novel valorization route for feather meal and highlights its potential in creating value-added materials for several applications in medicine, pharmaceuticals, and engineering areas.

Pecan (Carya illinoinensis (Wangenh.) K. Koch) nuts as an emerging source of protein: extraction, physicochemical and functional properties

BACKGROUND

The increasing demand for sustainable alternatives to traditional protein sources, driven by population growth, underscores the importance of protein in a healthy diet. Pecan (Carya illinoinensis (Wangenh.) K. Koch) nuts are currently underutilized as plant-based proteins but hold great potential in the food industry. However, there is insufficient information available on pecan protein, particularly its protein fractions. This study aimed to explore the physicochemical and functional properties of protein isolate and the main protein fraction glutelin extracted from pecan nuts.

RESULTS

The results revealed that glutelin (820.67 ± 69.42 g kg-1) had a higher crude protein content compared to the protein isolate (618.43 ± 27.35 g kg-1), while both proteins exhibited amino acid profiles sufficient for adult requirements. The isoelectric points of protein isolate and glutelin were determined to be pH 4.0 and pH 5.0, respectively. The denaturation temperature of the protein isolate (90.23 °C) was higher than that of glutelin (87.43 °C), indicating a more organized and stable conformation. This is further supported by the fact that the protein isolate had a more stable main secondary structure than glutelin. Both proteins demonstrated improved solubility, emulsifying, and foaming properties at pH levels deviating from their isoelectric points in U-shaped curves. Compared to the protein isolate, glutelin displayed superior water and oil absorption capacity along with enhanced gelling ability.

CONCLUSION

The protein isolate and glutelin from pecan nuts exhibited improved stability and competitive functional properties, respectively. The appropriate utilization of these two proteins will support their potential as natural ingredients in various food systems. © 2024 Society of Chemical Industry.

The composition, extraction, functional property, quality, and health benefits of coconut protein: A review

Coconut is widely appreciated for its distinctive flavor and is commonly utilized in the production of a variety of goods. Coconut protein, a by-product derived from coconut oil and coconut milk cake, is frequently underutilized or discarded. This study provides a comprehensive overview of the distribution and composition of coconut protein. Analyses reveal that coconut protein, specifically 11S globulin and 7S globulin, is predominantly found in coconut flesh. Furthermore, various extraction techniques for coconut protein, such as chemical, enzymatic, and physical methods, are discussed. The alkali dissolution and acid precipitation methods are widely utilized for extracting coconut protein, with the potential for enhancement through the incorporation of physical methods such as ultrasound. The evaluation of functional properties, quality, and health benefits of coconut protein is essential, given the limitations imposed by its solubility. Modification may be necessary to optimize its functional properties. Coconut presents a promising source of food protein, characterized by balanced amino acid composition, high digestibility, and low allergenic potential. In conclusion, this study provides a comprehensive overview of the extraction methods, functional properties, quality, and nutritional benefits of coconut protein, offering insights for potential future research directions in the field. Additionally, the information presented may serve as a valuable reference for incorporating coconut protein into plant-based food products.

A review of inhibition mechanisms of surimi protein hydrolysis by different exogenous additives and their application in improving surimi gel quality

It is well known that aquatic products such as fish and shellfish, when stored for a long period of time under inappropriate conditions, can suffer from muscle softening. This phenomenon is mainly caused by endogenous proteases, which are activated during heating and accelerates the degradation of myofibrillar proteins, directly leading to weaker gels and poorer water retention capacity. This paper reviews the changes in fish proteins during storage after death and the factors affecting protein hydrolysis. A brief overview of the extraction of protease inhibitors, polysaccharides and proteins is given, as well as their mechanism of inhibition of protein hydrolysis in surimi and the current status of their application to improve the properties of surimi.

Techno-functional, rheological, and chemical properties of plant-based protein ingredients obtained with dry fractionation and wet extraction

Dry fractionation is a promising technology for producing plant protein ingredients, owing to its minimal environmental impact and adaptability to diverse plant sources. Dry-fractionated proteins are still under development with limited applications in food industry due to lack of extensive knowledge about their physicochemical, rheological and chemical properties. Wet extraction though widely used, consumes high energy, water, and chemicals. In this research, the techno-functional, rheological, and chemical properties of commercial protein ingredients of various botanical species obtained via wet extraction (WE, n = 8) and dry fractionation (DF, n = 9) were investigated in order to identify their potential food applications. Compared to DF ingredients, WE proteins showed the lowest water solubility index and protein solubility at pH 7 and 9, as well as the lowest foaming and emulsifying capacities. This behavior can be explained by the presence of denatured protein structures in WE ingredients as suggested by the analysis of the secondary structure which revealed a higher presence of random coil structures. On the contrary, the presence of non-denatured structures in combination with other constituents like carbohydrates may have contributed to the high solubility and gelling properties of the DF proteins ingredients. While wet extraction technologies can offer a wide modulation of ingredient functionality, providing a broad spectrum of food applications, dry fractionation seems to guarantee a narrow range of techno-functional properties, although with potentially higher performance in certain areas like solubility and foaming.

Plant-based seafood alternatives: Current insights on the nutrition, protein-flavour interactions, and the processing of these foods

Fish are an important food source; however, the sustainability of current seafood supplies is a major concern for key stakeholders. The development of plant-based seafood alternatives may be suitable products to alleviate some of the pressures on aquatic ecosystems and help support environmental sustainability. However, the wide-spread adoption of these products weighs heavily on the ingredients used in the formulations which should not only satisfy nutritional and sustainability targets but must also meet consumer approval and functionality. In this review, we highlight recent advances in our understanding of the nutritional quality and sensory challenges in particular flavour (which includes taste and aroma), that have so far proven difficult to overcome in the development of plant-based seafood alternatives. Protein interactions that contribute to flavour development in plant-based seafood alternatives and the factors that impact these interactions are also discussed. We also review the recent advances in the innovative technologies used to improve the texture of products in this emerging food category. Finally, we highlight key areas for targeted research to advance the development of this growing segment of food products.

Bacterial interactions on nutrient-rich surfaces in the gut lumen

The intestinal lumen is a turbulent, semi-fluid landscape where microbial cells and nutrient-rich particles are distributed with high heterogeneity. Major questions regarding the basic physical structure of this dynamic microbial ecosystem remain unanswered. Most gut microbes are non-motile, and it is unclear how they achieve optimum localization relative to concentrated aggregations of dietary glycans that serve as their primary source of energy. In addition, a random spatial arrangement of cells in this environment is predicted to limit sustained interactions that drive co-evolution of microbial genomes. The ecological consequences of random versus organized microbial localization have the potential to control both the metabolic outputs of the microbiota and the propensity for enteric pathogens to participate in proximity-dependent microbial interactions. Here, we review evidence suggesting that several bacterial species adopt organized spatial arrangements in the gut via adhesion. We highlight examples where localization could contribute to antagonism or metabolic interdependency in nutrient degradation, and we discuss imaging- and sequencing-based technologies that have been used to assess the spatial positions of cells within complex microbial communities.

Blend of Baru (Dipteryx alata Vog.) By-Products as Nutritive and Healthy Food Ingredients: Chemical Composition, Functional Properties and Application in Plant-Based Burger

The chemical composition, antioxidant capacity and functional properties of mixtures of baru by-products, named baru food ingredients (BFI), were investigated and applied in a plant-based burger formulation. BFI were prepared from wasted baru by-products - partially defatted baru nut cake and baru pulp plus peel. A plant-based burger was developed and its chemical composition, antioxidant capacity, cooking and texture parameters were determined. BFI1 (50% partially defatted baru nut cake + 50% baru pulp plus peel) had the highest content of carbohydrate (31.9%), and dietary fibre (28.3%). BFI2 (75% partially defatted baru nut cake + 25% baru pulp plus peel) and BFI3 (90% partially defatted baru nut cake + 10% baru pulp plus peel) showed high concentration of protein and dietary fibre, and BFI3 had the highest protein content (29.5%). All BFI showed high concentration of total phenolics (402-443 mg GAE/100 g). Replacing textured pea protein of control burger (PPB) with 35% of BFI3 in the formulation of baru protein burger (BPB) resulted in a low-fat product (2.9%), with protein content (19.2%) comparable to the PPB (15.9%) and the commercial burger (mixed plant proteins - 16.3%). The BPB also showed a higher concentration of dietary fibre (4.9%) and phenolic compounds (128 mg GAE/100 g) than the control burger. BPB's cooking yield was the highest among the tested burgers. BPB had a softer texture when compared to other burgers. Baru food ingredients can be used as nutritive ingredients of health-promoting foods, especially in plant-based products, such as burger and meat analogues, or in hybrid meat products. BPB showed a healthy and nutritious profile.

On the modification of plant proteins: Traditional methods and the Hofmeister effect

With increasing consumer health awareness and demand from some vegans, plant proteins have received a lot of attention. Plant proteins have many advantages over animal proteins. However, the application of plant proteins is limited by a number of factors and there is a need to improve their functional properties to enable a wider range of applications. This paper describes the advantages and disadvantages of traditional methods of modifying plant proteins and the appropriate timing for their use, and collates and describes a method with fewer applications in the food industry: the Hofmeister effect. It is extremely simple but efficient in some respects compared to traditional methods. The paper provides theoretical guidance for the further development of plant protein-based food products and a reference value basis for improving the functional properties of proteins to enhance their applications in the food industry, pharmaceuticals and other fields.

Mulberry (Morus alba L.) leaf powder modified the processing of meat alternatives: Principal component analysis from apparent properties to chemical bonds

For texture control in plant-meat alternatives, the interrelationship between apparent characteristics and chemical bonds in high-fiber formulations remains unclear. The influence of mulberry leaf powder on apparent characteristics and chemical bonds of raw materials, block and strip products at addition amounts of 0.5-25% was analyzed. The results showed that 8% addition significantly increased the chewiness of the block by 98.12%. The strips' texture shows a downward trend, and the processing produced more redness and color difference. Additives promoted the formation of voids, lamellar and filamentous structures, and the strip produced more striped structures. Disulfide bonds significantly increased in the block, and the β-turn in the secondary structure enhanced by 12.20%. The β-turn transformed into a β-sheet in strips. Principal component analysis revealed that the texture improvement was associated with producing disulfide bonds and β-turn, providing a basis for high-fiber components to improve products' apparent characteristics by chemical bonds.

Effect of saturated and unsaturated fat on the physical properties of plant-based cheese

In many plant-based meat and dairy alternatives, coconut oil is frequently used to replicate the textural and structural properties of animal fats due to its high saturated fat content. Concerns about the health implications of saturated fat and the sustainability of coconut oil call for an exploration into alternative fat combinations in plant-based foods. The effects of saturated fatty acid (SFA) content on plant-based cheese physical characteristics were evaluated through five different ratios of coconut oil (CO) to sunflower oil (SO): 100%, 90%, 75%, 60%, 50%, 40%, 25%, 10%, and 0%. As determined through texture profile analysis, the hardness of the cheeses after setting at 5°C for 24h increased with increasing amounts of coconut oil due to the increasing solid fat content providing additional firmness. The samples with 100% coconut oil displayed satisfactory melt and stretch; however, the melt and stretch values were matched by adding as little as 25% sunflower oil. The melt and stretch values did not continue to increase with increasing saturated fat content but instead remained constant with increasing coconut oil addition. Rheological analysis of the cheeses during a temperature ramp from 20 to 95°C was assessed where the tanδ value at 95°C was used as a measure of cheese melt, where values ≥ 1 indicated a better melt. The 0% coconut oil cheese had the lowest tanδ (G″/G') value of 0.3, whereas the addition of 25% coconut oil into the cheese resulted in the tanδ increasing to values greater than 0.5. The 25% CO cheese sample also achieved a more similar complex viscosity (η*) to that of dairy cheese than all samples but the 75% CO cheese. Therefore, there is an opportunity to decrease the amount of coconut oil in plant-based cheese systems while maintaining good functional properties and improving the sustainability and health benefits of the final product.

The role of fiber in modulating plant protein-induced metabolic responses

The rising consumption of plant protein foods and the emergence of meat alternatives have prompted interest in the health benefits of such products, which contain fiber in addition to protein. This review investigates the effect of fiber on plant-based protein metabolism and evaluates its contribution to gut-derived health impacts. Plant proteins, which often come with added fiber, can have varying health outcomes. Factors such as processing and the presence of fiber and starch influence the digestibility of plant proteins, potentially leading to increased proteolytic fermentation in the gut and the production of harmful metabolites. However, fermentable fiber can counteract this effect by serving as a primary substrate for gut microbes, decreasing proteolytic activity. The increased amount of fiber, rather than the protein source itself, plays a significant role in the observed health benefits of plant-based diets in human studies. Differences between extrinsic and intrinsic fiber in the food matrix further impact protein fermentation and digestibility. Thus, in novel protein products without naturally occurring fiber, the health impact may differ from conventional plant protein sources. The influence of various fibers on plant-based protein metabolism throughout the gastrointestinal tract is not fully understood, necessitating further research.

Physicochemical property characterization, amino acid profiling and sensory evaluation of plant-based ice cream incorporated with soy, pea and milk proteins

This study examined the effects of incorporating milk protein concentrate (MPC), pea or soy proteins isolates (PPI and SPI) on the physicochemical, sensorial properties, and amino acid composition of ice creams containing 7% protein, in comparison to dairy ice cream as a reference. As protein ingredients, PPI exhibited higher water and oil holding capacity but lower surface hydrophobicity than SPI and MPC. Viscosity of the mixes were proportional to the firmness of ice cream, and both were highest with use of PPI. MPC ice cream had most similar physical and sensory properties to reference. PPI and SPI ice cream mixes showed higher extent of fat coalescence than MPC and reference. PPI and SPI conferred structural stability to ice cream with lower melting rate and better shape retention, and ability to delay ice recrystallization during temperature flocculation as compared with SMP and MPC. Confocal laser scanning microscope images indicated that higher extent of protein aggregation and more air cells were found in PPI ice cream. Sensory and amino acid profile results revealed that PPI and SPI ice creams were inferior in taste, texture, and essential amino acids like methionine. This study offers insights for the development of high protein frozen desserts.

A comparative analysis of nutritional quality, amino acid profile, and nutritional supplementations in plant-based products and their animal-based counterparts in the UK

Plant-based (PB) food products have surged in popularity over the past decade. Available PB products in the UK market were extracted from NielsenIQ Brandbank and compared with animal-based (AB) counterparts in their nutrient contents and calculated Nutri-Scores. The amino acid contents of four beef products and their PB alternatives were analysed by LC-MS/MS. PB products consistently exhibited significantly higher fibre content across all food groups. Protein was significantly higher in AB products from all food groups except beef and ready meals. PB products were more likely to have higher Nutri-Scores compared to AB counterparts, albeit with greater score variability within each food group. Nutrient fortifications were primarily focused on dairy and ready meals; the most supplemented nutrient was vitamin B12 (found in 15% of all products). A higher proportion of EAAs in relation to total protein content was observed in all beef products.

Incorporation of Locust Bean Gum and Solid Lipid Microparticles as Strategies to Improve the Properties and Stability of Calcium-Rich Soy Protein Isolate Gels

The present study aimed to investigate the properties of calcium-rich soy protein isolate (SPI) gels (14% SPI; 100 mM CaCl2), the effects of incorporating different concentrations locust bean gum (LBG) (0.1-0.3%, w/v) to the systems and the stability of the obtained gels. Also, the incorporation of solid lipid microparticles (SLMs) was tested as an alternative strategy to improve the system's stability and, therefore, potential to be applied as a product prototype. The gels were evaluated regarding their visual aspect, rheological properties, water-holding capacities (WHCs) and microstructural organizations. The CaCl2-induced gels were self-supported but presented low WHC (40.0% ± 2.2) which was improved by LBG incorporation. The obtained mixed system, however, presented low stability, with high syneresis after 10 days of storage, due to microstructural compaction. The gels' stability was improved by SLM incorporation, which decreased the gelled matrices' compaction and syneresis for more than 20 days. Even though the rheological properties of the emulsion-filled gels (EFGs) were very altered due to the ageing process (which may affect the sensory perception of a future food originated from this EFG), the incorporation of SLMs increased the systems potential to be applied as a calcium-rich product prototype.

Ingredient Functionality of Soy, Chickpea, and Pea Protein before and after Dry Heat Pretreatment and Low Moisture Extrusion

This study investigates the impact of dry heat pretreatment on the functionality of soy, chickpea, and pea protein ingredients for use in texturized vegetable protein (TVP) production via low moisture extrusion. The protein powders were heat-treated at temperatures ranging from 80 °C to 160 °C to modulate the extent of protein denaturation and assess their effects on RVA pasting behavior, water absorption capacity (WAC), and color attributes. The results indicate that the pretreatment temperature significantly influenced the proteins' functional properties, with an optimal temperature of 120 °C enhancing pasting properties and maintaining WAC, while a higher pretreatment temperature of 160 °C led to diminished ingredient functionality. Different protein sources exhibited distinct responses to heat pretreatment. The subsequent extrusion processing revealed significant changes in extrudate density and color, with increased density and darkness observed at higher pretreatment temperatures. This research provides insights into the interplay between protein sources, pretreatment conditions, and extrusion outcomes, highlighting the importance of controlled protein denaturation for developing high-quality, plant-based meat analogues. The findings have broad implications for the optimization of meat analogue manufacturing, with the aim of enhancing the sensory experience and sustainability of plant-based foods.

Understanding Stabilization of Oil-in-Water Emulsions with Pea Protein─Studies of Structure and Properties

This study investigates the stability and structure of oil-in-water emulsions stabilized by pea protein. Of the wide range of emulsion compositions explored, a region of stability at a minimum of 5% w/v pea protein and 30-50% v/v oil was determined. This pea protein concentration is more than what is needed to form a layer covering the interface. X-ray scattering revealed a thick, dense protein layer at the interface as well as hydrated protein dispersed in the continuous phase. Shear-thinning behavior was observed, and the high viscosity in combination with the thick protein layer at the interface creates a good stability against creaming and coalescence. Emulsions in a pH range from acidic to neutral were studied, and the overall stability was observed to be broadly similar independently of pH. Size measurements revealed polydisperse protein particles. The emulsion droplets are also very polydisperse. Apart from understanding pea protein-stabilized emulsions in particular, insights are gained about protein stabilization in general. Knowledge of the location and the role of the different components in the pea protein material suggests that properties such as viscosity and stability can be tailored for various applications, including food and nutraceutical products.

Extraction, Modification, Biofunctionality, and Food Applications of Chickpea (Cicer arietinum) Protein: An Up-to-Date Review

Plant-based proteins have gained popularity in the food industry as a good protein source. Among these, chickpea protein has gained significant attention in recent times due to its high yields, high nutritional content, and health benefits. With an abundance of essential amino acids, particularly lysine, and a highly digestible indispensable amino acid score of 76 (DIAAS), chickpea protein is considered a substitute for animal proteins. However, the application of chickpea protein in food products is limited due to its poor functional properties, such as solubility, water-holding capacity, and emulsifying and gelling properties. To overcome these limitations, various modification methods, including physical, biological, chemical, and a combination of these, have been applied to enhance the functional properties of chickpea protein and expand its applications in healthy food products. Therefore, this review aims to comprehensively examine recent advances in Cicer arietinum (chickpea) protein extraction techniques, characterizing its properties, exploring post-modification strategies, and assessing its diverse applications in the food industry. Moreover, we reviewed the nutritional benefits and sustainability implications, along with addressing regulatory considerations. This review intends to provide insights into maximizing the potential of Cicer arietinum protein in diverse applications while ensuring sustainability and compliance with regulations.

Heat-Induced Gelation of Chickpea and Faba Bean Flour Ingredients

This study aimed to investigate the gelling behavior of faba bean (FB) and chickpea (CP) flour between 10 and 20% (w/w) concentration at pH 3.0, 5.0, and 7.0. Both sources formed at pH 3.0 and 5.0 self-standing gels with 12% (w/w) of flour, while 16% (w/w) of flour was required to obtain a gel at pH 7.0. During gelling between 40 and 70 °C, a sharp increase of the elastic modulus G' was observed in both flours, mainly due to water absorption and swelling of the starch, one of the major constituents in the ingredients. Increasing the temperature at 95 °C, G' increased due to the denaturation of globulins and therefore the exposure of their internal part, which allowed more hydrophobic interactions and the formation of the gel. After cooling, both FB and CP gels displayed a solid-like behavior (tan δ ranging between 0.11 and 0.18) with G' values at pH 3.0 and 5.0 significantly (p < 0.05) higher than those at pH 7.0, due to the lower electrostatic repulsions at pHs far from the isoelectric point. The rheological properties were supported by the water binding capacity values, confirming the better gels' strength described by rheological analysis. These results will enhance our understanding of the role of legume flours in formulating innovative and sustainable food products as alternatives to animal ones.

Hempseed protein-derived short- and medium-chain peptides and their multifunctional properties

Nowadays, the growing knowledge about the high nutritional value and potential functionality of hempseeds, the edible fruits of the Cannabis sativa L. plant, has sparked a surge in interest in exploring the worthwhile attributes of hempseed proteins and peptides. This trend aligns with the increasing popularity of hemp-based food, assuming a vital role in the global food chain. This chapter targets the nutritional and chemical composition of hempseed in terms of short- and medium-chain bioactive peptides. The analytical approaches for their characterization and multifunctional properties are summarized in detail. Moreover, the processing, functionality, and application of various hempseed protein products are discussed. In the final part of the chapter-for evaluating their propensity to be transported by intestinal cells-the transepithelial transport of peptides within hempseed protein hydrolysate is highlighted.

Techno-functional properties of dry-fractionated plant-based proteins and application in food product development: a review

Dry-fractionated protein concentrates are gaining attention because they are produced using a versatile and sustainable technology, which can be applied to a wide range of plant material. To facilitate their utilization in new product development, it is crucial to obtain a comprehensive overview of their techno-functional properties. The present review aims to examine the techno-functional properties of dry-fractionated protein concentrates and describe their primary applications in food products, considering the published works in the last decade. The techno-functional properties of proteins, including water absorption capacity, emulsifying and foaming properties, gelling ability or protein solubility, are relevant factors to consider during food formulation. However, these properties are significantly influenced by the extraction technology, the type of protein and its characteristics. Overall, dry-fractionated proteins are characterized by high protein solubility, high foaming ability and foam stability, and high gelling ability. Such properties have been exploited in the development of food, such as bakery products and pasta, with the aim of increasing the protein content and enhancing the nutritional value. Additionally, innovative foods with distinctive textural and nutritional characteristics, such as meat and dairy analogues, have been developed by using dry-fractionated proteins. The results indicate that the study of these ingredients still needs to be improved, including their application with a broader range of plant materials. Nevertheless, this review could represent an initial step to obtaining an overview of the techno-functional properties of dry-fractionated proteins, facilitating their use in foods. © 2023 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Analysis of ingredient list and nutrient composition of plant-based burgers available in the global market

The nutrient composition of plant-based burgers is a key factor when making their purchase/consumption decision to maintain a balanced diet. For this reason, ingredient list and nutritional information of burgers launched in the global market were retrieved from their labels. Products were classified based on the technology development, market position and region of the manufacturer. From the ingredient analysis, we observed a high heterogeneity in the ingredients used, a predominance of soy and wheat as main sources of proteins, and the increasing use of new protein sources (e.g. peas, other types of beans and pseudo-cereals). Oil was the most cited ingredient followed by salt. Nutritional composition varied mainly depending on the region with no clear pattern among countries. To less extent, technology development resulted in traditional products with lower amounts of protein and higher amounts of carbohydrates. Vegan and vegetarian products showed limited differences due to the high intra-heterogenicity.

Tailoring the Techno-Functional Properties of Fava Bean Protein Isolates: A Comparative Evaluation of Ultrasonication and Pulsed Electric Field Treatments

The fava bean protein isolate (FBPI) holds promise as a sustainable plant-based protein ingredient. However, native FBPIs exhibit limited functionality, including unsuitable emulsifying activities and a low solubility at a neutral pH, restricting their applications. This study is focused on the effect of ultrasonication (US) and pulsed electric fields (PEF) on modulating the techno-functional properties of FBPIs. Native FBPIs were treated with US at amplitudes of 60-90% for 30 min in 0.5 s on-and-off cycles and with PEF at an electric field intensity of 1.5 kV/cm with 1000-4000 pulses of 20 μs pulse widths. US caused a reduction in the size and charge of the FBPIs more prominently than the PEF. Protein characterization by means of SDS-PAGE illustrated that US and PEF caused severe-to-moderate changes in the molecular weight of the FBPIs. In addition, a spectroscopic analysis using Fourier-transform infrared (FTIR) and circular dichroism (CD) revealed that US and the PEF induced conformational changes through partial unfolding and secondary structure remodeling from an α-helix to a β-sheet. Crystallographic and calorimetric determinations indicated decreased crystallinity and lowered thermal transition temperatures of the US- and PEF-modified FBPIs. Overall, non-thermal processing provided an effective strategy for upgrading FBPIs' functionality, with implications for developing competitive plant-based protein alternatives.

Effect of Protein Surface Hydrophobicity and Surface Amines on Soy Adhesive Strength

Soy is considered one of the most promising natural materials for manufacturing wood adhesives due to its low cost, high protein content, and ready availability. However, more cost-effective ways of improving its wet shear strength are needed to achieve wider market acceptance. Protein adhesive wet strength depends on the use of (typically expensive) crosslinking additives as well as the processing/denaturation of the protein. It has been commonly stated in the literature that protein denaturation leads to higher bond strength by activating the surface and exposing the reactive groups. Therefore, we investigated how differences in surface reactive groups (surface hydrophobicity and reactive amine groups) brought on with different denaturation treatments relate to bonding performance. Fourteen soy protein isolates (SPIs) with different denaturation histories were investigated. Characterization of the SPIs included surface hydrophobicity, surface amine content, extent of protein hydrolysis, and bond strength (wet and dry, with and without polyamidoamine epichlorohydrin (PAE) crosslinking agent) by ASTM D7998. The molecular weight patterns showed that proteins denatured by extensive hydrolysis had very low bond strengths. Adding the crosslinker, PAE, improved all the shear strength values. We found that the number of water-accessible reactive amine groups on protein surfaces had no impact on the adhesive strength, even with the amine-reactive crosslinker, PAE. Conversely, increased surface hydrophobicity was beneficial to adhesive strength in all cases, though this correlation was only statistically significant for wet strength without PAE. While, in general, denatured proteins are typically thought to form better bonds than native state proteins, this work suggests that it matters how proteins are denatured, and what surfaces become exposed. Denaturation by hydrolysis did not improve bond strength, and extensive hydrolysis seemed highly detrimental. Moreover, exposing hydrophobic surface groups was beneficial, but exposing covalent bond-forming reactive amine groups was not.

Transglutaminase-Induced Polymerization of Pea and Chickpea Protein to Enhance Functionality

Pulse proteins, such as pea and chickpea proteins, have inferior functionality, specifically gelation, compared to soy protein, hindering their applications in different food products, such as meat analogs. To close the functionality gap, protein polymerization via targeted modification can be pursued. Accordingly, transglutaminase-induced polymerization was evaluated in pea protein isolate (PPI) and chickpea protein isolate (ChPI) to improve their functionality. The PPI and ChPI were produced following a scaled-up salt extraction coupled with ultrafiltration (SE-UF) process. Transglutaminase (TGase)-modified PPI and ChPI were evaluated in comparison to unmodified counterparts and to commercial protein ingredients. Protein denaturation and polymerization were observed in the TG PPI and TG ChPI. In addition, the TGase modification led to the formation of intermolecular β-sheet and β-turn structures that contributed to an increase in high-molecular-weight polymers, which, in turn, significantly improved the gel strength. The TG ChPI had a significantly higher gel strength but a lower emulsification capacity than the TG PPI. These results demonstrated the impact of the inherent differences in the protein fractions on the functional behavior among species. For the first time, the functional behavior of the PPI and ChPI, produced on a pilot scale under mild processing conditions, was comprehensively evaluated as impacted by the TGase-induced structural changes.

Pulse Protein Isolates as Competitive Food Ingredients: Origin, Composition, Functionalities, and the State-of-the-Art Manufacturing

The ever-increasing world population and environmental stress are leading to surging demand for nutrient-rich food products with cleaner labeling and improved sustainability. Plant proteins, accordingly, are gaining enormous popularity compared with counterpart animal proteins in the food industry. While conventional plant protein sources, such as wheat and soy, cause concerns about their allergenicity, peas, beans, chickpeas, lentils, and other pulses are becoming important staples owing to their agronomic and nutritional benefits. However, the utilization of pulse proteins is still limited due to unclear pulse protein characteristics and the challenges of characterizing them from extensively diverse varieties within pulse crops. To address these challenges, the origins and compositions of pulse crops were first introduced, while an overarching description of pulse protein physiochemical properties, e.g., interfacial properties, aggregation behavior, solubility, etc., are presented. For further enhanced functionalities, appropriate modifications (including chemical, physical, and enzymatic treatment) are necessary. Among them, non-covalent complexation and enzymatic strategies are especially preferable during the value-added processing of clean-label pulse proteins for specific focus. This comprehensive review aims to provide an in-depth understanding of the interrelationships between the composition, structure, functional characteristics, and advanced modification strategies of pulse proteins, which is a pillar of high-performance pulse protein in future food manufacturing.

Effects of Dextran on the Gel Properties of Faba Bean Protein Isolates Prepared Using Different Processes

The properties of faba bean (Vicia faba L.) protein isolate (FPI) gels depend on their starting protein material and can be modulated by the addition of polysaccharides. In order to investigate the interplay between these two factors, commercial FPI (FPI1) and FPI prepared in-house (FPI2) were used to fabricate glucono-delta-lactone-induced gels, with or without dextran (DX) addition. FPI1 exhibited lower solubility in water and a larger mean particle size, likely because it experienced extensive degradation due to the intense conditions involved in its preparation. The FPI1 gel showed a similar water-holding capacity as the FPI2 gel; however, its hardness was lower and viscoelasticity was higher. After DX addition, the hardness of both FPI gels decreased, while their water-holding capacity increased. Interestingly, DX addition decreased the viscoelasticity of the FPI1 gel but enhanced the viscoelasticity of the FPI2 gel. The microstructural analysis demonstrated that the density of the aggregation network decreased in the FPI1 gel after DX addition but increased in the FPI2 gel. This was consistent with the changes observed in the dominant protein interaction forces in these gels after DX addition. Overall, these findings have the potential to guide ingredient selection for the tailored preparation of FPI gels.