Seed Storage Proteins of Faba Bean ( Vicia faba L): Current Status and Prospects for Genetic Improvement

Variation in composition of storage proteins, minor proteins and amino acids across faba bean cultivars

This study aimed to investigate variations in protein profiles and amino acid (AA) compositions in faba bean seeds among 10 different cultivars. The compositions of salt-soluble proteins and AA were identified and quantified by label-free nano LC-MS/MS and LC-MS/MS (Triple Quadrupole), respectively. The protein contents (dry basis) in faba bean seeds were measured using the DUMAS method, ranging from 21.6 % to 26.8 %. By nano LC-MS/MS, 103 unique proteins were identified under point mutation monitoring analysis and of these, 61 proteins were quantified by label-free quantification. In all cultivars, vicilin and legumin were the most abundant proteins, respectively, varying from 16 to 39 % and 12 to 34 % of total protein content (w/w). The relative abundance of minor proteins like Bowman-Birk proteinase inhibitors was quantified to constitute around 1 % of the total protein content (w/w). There were 400 mg essential amino acids (EAAs) detected per gram protein, where histidine showed the highest concentration (64-82 mg/g protein) in all faba beans.

Osborne fractionation and techno-functional properties of Faba bean flours from eight varieties grown under a temperate maritime climate

Faba bean (Vicia faba) is a high-protein crop, well-suited as a break crop for cereal rotations with high nitrogen-fixing ability. This study provides comprehensive characterisation encompassing agronomic, nutritional and techno-functional properties of faba bean varieties (4 spring-sown and 4 winter-sown) and explores different protein fractions recovery using Osborne fractionation method. All varieties investigated are suited to cultivate in a temperate maritime climate, especially the winter-sown varieties produced a higher average yield (6.0 t/ha) compared to spring-sown varieties (5.0 t/ha). 'CARTOUCHE' flour exhibited the highest protein content (33.01 %), and all flours were rich in lysine (1.75 to 1.43 g/100 g of flour). 'TUNDRA' flour showed highest peak viscosity (PV, 541 cP). The Osborne fractionation yielded albumins (15.08 to 19.45 %) along with the highest protein composition (84.17 to 88.79 %) of the total protein recovery. Overall, faba bean flours could be used as functional ingredient in addition to its source of alternative proteins.

Effects of germination on the digestibility of instant soybean powders based on an in vitro digestion model of the aged static gastrointestinal tract

Germination and heat processing can improve the digestibility of soybean protein, so for the elderly and people with gastrointestinal dysfunction, instant soybean powder is an ideal source for protein intake. In this study, the changes in protein and anti-nutritional factors in the instant germinating soybean powders were investigated systematically, and the aged gastrointestinal digestion model analyzed the digestive characteristics of instant germinating soybean powders. The results showed that during processing, particle size, disulfide bond, and β-sheets decreased, free sulfhydryl and α-helix increased. The change resulted in the decrease of proteolysis degree and particle size of gastrointestinal digestive products, and the increase of surface hydrophobic index. At the same time, anti-nutritional factors decreased by about 30 % to 60 %. The above reasons are combined with the protein digestibility of S72 5.88 % higher than Y0. This study proved that instant soybean powder is more conducive to the digestion and absorption of the elderly.

Targeted genotyping (90K-SPET) facilitates genome-wide association studies and the prediction of yield-related traits in faba bean (Vicia faba L.)

BACKGROUND

Establishing faba bean (Vicia faba L.) as a major protein crop in Europe requires developing high-yielding varieties. However, the genetic regulation of yield-related traits is currently under-explored. These traits can be improved by exploiting the extensive but largely uncharacterized faba bean germplasm. Our study aimed to identify associations between 38,014 single nucleotide polymorphisms (SNPs) and flowering time (FT), plant height (PH), pod length (PL), seeds per pod (SP), and single seed weight (SSW) in 245 faba bean accessions (CGN panel) via a Genome-Wide Association Study (GWAS). The accessions were grown in 2021 and 2022 in the Netherlands. Additionally, we developed genomic selection (GS) models to predict the genetic merit within large germplasm collections for the mentioned traits, as well as yield (YLD).

RESULTS

The CGN panel was an optimal panel for performing high-resolution GWAS, showing large phenotypic variation, high narrow-sense heritability for all traits, and minimal genetic relatedness among accessions. Population structure analysis revealed the presence of four genetic groups. GWAS uncovered 33 SNP-trait associations in 2021 and 17 in 2022. We identified one stable QTL for FT and four for SSW over the two years, representing key molecular markers for testing in breeding applications. Short linkage disequilibrium decay (~ 268 Kbp) facilitated the identification of several important candidate genes with interesting homologs in other crops. Ten SNPs in 2021 and five in 2022 were predicted to be intra-genic missense variants, potentially altering protein function. Moreover, modeling the SNP effect simultaneously via Bayesian GS showed promising predictive ability (PA) and prediction accuracy (ACC), supporting their potential application in germplasm-improvement programs. Predictive ability ranged from 0.58 to 0.81 in 2021, and 0.47 to 0.85 in 2022 for different traits. Additionally, across-year predictions showed stable PA.

CONCLUSION

GWAS revealed promising QTLs for use in molecular breeding and highlighted new candidate genes. Interestingly, the prediction of intra-genic SNPs categorized 15 SNPs as putatively affecting protein function. Moreover, we demonstrated for the first time in faba bean that GS has the potential to unlock untapped diversity in genebank collections and accelerate trait integration into faba bean breeding programs.

Study on structure, properties and formation mechanism of cassava starch-faba bean protein heat-induced gel

In this experiment, the effects of different concentrations of cassava starch (CS) on the gel behavior of faba bean protein (FBP) were studied, focusing on the structural characteristics, gel characteristics and physical and chemical characteristics of the gel system. Specifically, with the increase of CS concentration from 4 % to 12 %, the morphology of the sample changed from fluid to gel solid. From the molecular structure, different concentrations of CS affected the secondary and tertiary structures of FBP protein, which made aromatic amino acids move to the surface of protein and promoted the transformation from α-helix to β-sheet. In addition, free sulfhydryl groups are converted into disulfide bonds, which increases the number of hydrogen bonds in the system. Microscopically, high temperature treatment leads to the cracking of CS and FBP structures, which enhances the noncovalent interactions between them, and forms a compact and smaller pore three-dimensional network structure, providing more channels for external moisture to transfer to the inside. From the gel characteristics, the water holding capacity, viscoelasticity and mechanical behavior of the composite gel were improved when the concentration of CS was 6 %-12 %. This work provides reference for the application of cassava starch-faba bean protein gel in specific food and medicine fields.

Characterization of the rheological and technological properties of the plant-based ice cream of the açaí and jabuticaba peel flour with faba bean protein

The development of a plant-based ice cream using an alternative protein together with açaí and jabuticaba peel flour is a way of meeting the demands for plant-based products and valuing the Brazilian biodiversity. Thus, this study aimed to evaluate the rheological and technological characterization of plant-based ice cream of the açaí and jabuticaba peel flour with faba bean protein. Eight formulations were prepared using different concentrations of açaí and jabuticaba peel flour preparation (25%-40%), faba bean protein concentrate (FBPC) (8.5%-20%) and coconut oil (5%-10%). The study revealed that protein concentration having a significant impact on rheological properties. Formulations with high FBPC presented resistance to melting, less overrun and increased the hardness, while moderate levels, especially below 10%, presented characteristics equivalent to the control ice cream (4% faba bean protein), similar to the conventional commercial dairy ice cream. Based on these results, the ideal formulation would have 40% of açaí preparation, 8.5% of FBPC and 6.35% of coconut oil. These findings contribute to understand the complex interactions between the composition and physical characteristics of ice cream with faba bean protein and tropical fruits, aiming to improve its technological properties.

Green guaje (Leucaena leucocephala) and pigmented guaje (Leucaena esculenta) as sources of antioxidant and immunomodulatory peptides

In recent years, there has been a growing interest in plant-based diets, particularly legumes, as a sustainable and healthy dietary choice. This study breaks new ground by investigating the effects of simulated gastrointestinal digestion on green (Leucaena leucocephala) and pigmented (Leucaena esculenta) guaje proteins. We evaluated the antioxidant and immunomodulatory properties of ultrafiltered fractions resulting from digestion in a macrophage model. Both fractions showed promising potential as radical scavengers. The fraction <5 kDa from pigmented guaje, even at the lowest doses tested, significantly (p < 0.05) inhibited the release of pro-inflammatory cytokines TNF-α and IL-6, and demonstrated an immunomodulatory effect by reducing the levels of ROS and NO. These findings suggest that green and pigmented guaje could be a valuable source of bioactive peptides, potentially used as a coadjutant for treating and preventing oxidative stress and inflammation-associated non-communicable diseases through the utilization of underutilized legumes.

Vicilin, a chitin binding protein from Sesbania grandiflora: Structural insights and functional potential as an antifungal agent

Sesbania grandiflora, a fast-growing shrub from the Fabaceae family, is extensively researched for its therapeutic properties. Despite its highly valued medicinal properties, there have been no reports on exploring the proteome of Sesbania grandiflora. The present study aims to address this gap by investigating the proteomic profile of Sesbania grandiflora seeds with a primary focus on identifying storage proteins. The proteomic data disclosed an abundant vicilin protein from the seeds, which was subsequently purified to homogeneity. Structural analysis revealed the heterotrimeric nature of the purified protein, with an intact molecular weight of approximately 130 kDa and the presence of N-glycosylation. Further, in-gel digested protein bands were analyzed via LC-MS/MS, and partial de novo sequences were deduced through a homology-driven proteomic approach. Circular dichroism spectroscopy revealed that the vicilin is predominantly composed of β-sheet structures, with a melting temperature of 69.3 °C. Functional studies demonstrated the protein's chitin-binding capability via chitin affinity chromatography, highlighting its anti-mycotic properties. The antifungal activity was quantified, showing that approximately 15 μM of the purified protein inhibited 50 % of Fusarium oxysporum growth. A cell permeability assay with propidium iodide staining confirmed the interaction between the protein and the fungal cell wall, highlighting its role in antifungal activity.

Morphological, physiological, and transcriptomic analyses indicate that cell wall properties and antioxidant processes are potential targets for improving the aluminium tolerance of broad beans

Aluminium (Al) stress is the second-leading abiotic stress on crops. An improved understanding of the response mechanisms of plants to Al stress will provide scientific guidance for enhancing the crops' tolerance to Al stress. In this study, Al stress (50-200 μM AlCl3) caused visible damage to broad bean (Vicia faba L.) roots rather than shoots, which was attributed to Al accumulation and distribution in different tissues. Root transcriptomic analysis revealed that Al stress altered cell wall properties by downregulating lignin synthesis and several xyloglucan endotransglucosylase/hydrolase-, expansin- and peroxidase (POD)-encoding genes, which likely weakened cell extensibility to inhibit root growth. Additionally, Al stress impeded reactive oxygen species scavenging pathways involving POD activity and flavonoid biosynthesis, leading to oxidative damage characterised by malondialdehyde accumulation. These results indicate that optimising cell wall properties and/or enhancing antioxidant processes are crucial for alleviating Al toxicity to broad beans. Interestingly, exogenous application (500 and 1000 μM) of the flavonoid apigenin effectively alleviated Al toxicity in broad bean roots by partially improving the total antioxidant capacity of the roots. This study contributes to understanding the interaction between plants and Al and provides new strategies to alleviate Al toxicity in crops.

Wild Lathyrus-A Treasure of Novel Diversity

Grasspea (Lathyrus sativus L.) is a climate-smart legume crop with adaptation to fragile agroecosystems. The genus Lathyrus is recognized for its vast genetic diversity, encompassing over 160 species, many of which are cultivated for various purposes across different regions of the world. Among these, Lathyrus sativus is widely cultivated as food, feed, and fodder in South Asia, Sub-Saharan Africa, and the Central and West Asia and North Africa (CWANA) regions. Its global cultivation has declined substantially due to the stigma posed by the presence of neurotoxin β-N-oxalyl-L-α, β-diaminopropionic acid (β-ODAP) in its seeds and green foliage. Overconsumption for a longer period of grasspea seeds harvested from landraces may lead to a neurological disorder called neurolathyrism in humans. ODAP is an obstacle for grasspea expansion, but crop wild relatives (CWRs) have been found to offer a solution. The incorporation of CWRs, particularly Lathyrus cicera, and landraces into breeding programs may reduce the ODAP content in grasspea varieties to a safer level. Recent advances in genomics-assisted breeding have expanded the potential for utilizing challenging CWRs to develop grasspea varieties that combine ultra-low ODAP levels with improved yield, stability, and adaptability. Further progress in omics technologies-such as transcriptomics, proteomics, and metabolomics-along with genome sequencing and editing, has greatly accelerated the development of grasspea varieties with reduced or zero ODAP content, while also enhancing the plant's agronomic value. This review highlights the significance of utilizing CWRs in pre-breeding programs, and harnessing advanced tools and technologies to enhance the performance, adaptability, and resilience of grasspea in response to changing environmental conditions.

Plant growth-promoting rhizobacteria and biochar as bioeffectors and bioalleviators of drought stress in faba bean (Vicia faba L.)

Plants are subjected to a variety of abiotic stressors, including drought stress, that are fatal to their growth and ability to produce under natural conditions. Therefore, the present study was intended to investigate the drought tolerance potential of faba bean (Vicia faba L.) plants under the co-application of biochar and rhizobacteria, Cellulomonas pakistanensis (National Culture Collection of Pakistan (NCCP)11) and Sphingobacterium pakistanensis (NCCP246). The experiment was initiated by sowing the inoculated seeds with the aforementioned rhizobacterial strains in earthen pots filled with 3 kg of sand-mixed soil and 5% biochar. The morphology of biochar was observed with highly porous nature, along with the detection of various essential elements. The biochemical and physiological data showed that phenolic compounds and osmolytes were adversely affected by the induction of drought stress. However, the application of biochar and rhizobacteria boosted the level of flavonoids on average by 52.03%, total phenols by 50.67%, soluble sugar by 82.85%, proline by 76.81%, glycine betaine by 107.25%, and total protein contents by 89.18% in all co-treatments of biochar and rhizobacteria. In addition, stress indicator compounds, including malondialdehyde (MDA) contents and H2O2, were remarkably alleviated by 54.21% and 47.03%, respectively. Similarly, the amplitude of antioxidant enzymes including catalase, peroxidase, superoxide dismutase, ascorbate peroxidase, and guaiacol peroxidase was also enhanced by 63.80%, 80.95%, 37.87%, and 58.20%, respectively, in all co-treatments of rhizobacteria and biochar. Conclusively, biochar and rhizobacteria have a magnificent role in enhancing the drought tolerance potential of crop plants by boosting the physio-biochemical traits and enhancing the level of antioxidant enzymes.

Enhancing the nutritional and bioactive benefits of faba bean flour by combining preprocessing and thermoplastic extrusion: A comprehensive study on digestion-resistant peptides

This research assessed how three preprocessing techniques [soaking (S), soaking and reconstitution (SR), and soaking and dehulling (SD)] impact the protein digestibility and bioactivity of faba bean flours when combined with thermoplastic extrusion. Samples were compared against a control (C) of extruded faba bean flour without preprocessing. Applying preprocessing techniques followed by extrusion diminished antinutrient levels while enhancing protein hydrolysis and in vitro bioactivity in higher extent compared to C. Specifically, SD combined with extrusion was the most effective, achieving an 80% rate of protein hydrolysis and uniquely promoting the release of gastric digestion-resistant proteins (50-70 kDa). It also resulted in the highest release of small peptides (<3kDa, 22.51%) and free amino acids (15.50%) during intestinal digestion. Moreover, while all preprocessing techniques increased antioxidant (ABTS radical-scavenging), antidiabetic, and anti-hypertensive activities, SD extruded flour displayed the highest levels of dipeptidyl peptidase inhibition (DPP-IVi, IC50=13.20 µg/mL), pancreatic α-amylase inhibition (IC50=8.59 mg/mL), and angiotensin I-converting enzyme inhibition (ACEi, IC50=1.71 mg protein/mL). As a result, it was selected for further peptide and in silico bioactive analysis. A total of 24 bioactive peptides were identified in intestinal digests from SD extruded flour, all with potential DPP-IVi and ACEi activities, and six were also predicted as antioxidant peptides. VIPAGYPVAIK and GLTETWNPNHPEL were highlighted as resistant bioactive peptides with the highest antidiabetic and antioxidant potential. Our findings demonstrated that combining preprocessing (particularly SD) and thermoplastic extrusion enhances protein digestibility in faba beans and promotes the release of beneficial bioactive peptides in the intestine.

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.

Assessing agronomic performance, chocolate spot resistance, and heat tolerance for diverse Vicia faba genotypes under varying environmental conditions

Chocolate spot and heat stress devastatingly impact the production of faba bean, particularly under prevailing climatic changes and rising drastic environmental conditions. Hence, the adaptability of faba bean performance is a decisive objective of plant breeders to ensure its sustainable production. The present study aimed to evaluate the agronomic performance and stability of diverse eleven faba bean genotypes for yield characters, chocolate spot, and heat stress in eight different growing environments. The faba bean genotypes were evaluated at two sowing dates in two different locations during two growing seasons. The evaluated eleven faba bean genotypes were sown timely in autumn (25 October) and late sowing in early winter (25 November) in Bilbeis and Elkhatara during 2020 and 2021 growing seasons. The results exhibited substantial differences among the evaluated sowing dates, locations, and faba bean genotypes for all studied characters. The genotypes Sakha-3, Nubaria-3, Nubaria-5, Misr-3, and Wadi-1 were able to produce acceptable yield and quality characters under timely sowing in autumn and late sowing in early winter in all tested environments. Moreover, the genotypes Nubaria-3, Nubaria-4, Nubaria-5, Sakha-4, Giza-3, and Triple White exhibited better resistance to chocolate spot. The assessed faba bean genotypes were evaluated under late sowing to expose the plants to high temperature stress at flowering and throughout the anthesis and seed-filling stages. The genotypes Nubaria-5, Nubaria-3, Nubaria-4, Sakha-3, Sakha-4, Wadi-1, and Misr-3 possessed tolerance to heat stress more than the other genotypes. Different statistical methods were applied to study the stability of assessed genotypes such as joint regression, Additive Main Effect and Multiplicative Interaction (AMMI) analysis, AMMI stability value, Wricke's and Ecovalence values. The estimated stability parameters were consistent in depicting the stability of the assessed faba bean genotypes. The findings revealed that Sakha-1, Misr-3, Nubaria-4, and Nubaria-5 demonstrated stable and desirable performance across all tested environments. The heatmap was employed to classify the assessed faba bean genotypes into different groups based on agronomic performance, chocolate spot resistance and heat stress tolerance. Nubaria-3, Nubaria-4, Nubaria-5, and Misr-3 had the best performance for agronomic performance, chocolate spot resistance, and heat stress tolerance. The obtained results provide evidence of employing promising faba bean genotypes for improving the stability of agronomic performance, chocolate spot resistance, and heat stress tolerance in breeding programs principally under unprecedented climate fluctuations.

Genome-wide association study for yield-related traits in faba bean (Vicia faba L.)

Yield is the most complex trait to improve crop production, and identifying the genetic determinants for high yield is a major issue in breeding new varieties. In faba bean (Vicia faba L.), quantitative trait loci (QTLs) have previously been detected in studies of biparental mapping populations, but the genes controlling the main trait components remain largely unknown. In this study, we investigated for the first time the genetic control of six faba bean yield-related traits: shattering (SH), pods per plant (PP), seeds per pod (SP), seeds per plant (SPL), 100-seed weight (HSW), and plot yield (PY), using a genome-wide association study (GWAS) on a worldwide collection of 352 homozygous faba bean accessions with the aim of identifying markers associated with them. Phenotyping was carried out in field trials at three locations (Spain, United Kingdom, and Serbia) over 2 years. The faba bean panel was genotyped with the Affymetrix faba bean SNP-chip yielding 22,867 SNP markers. The GWAS analysis identified 112 marker-trait associations (MTAs) in 97 candidate genes, distributed over the six faba bean chromosomes. Eight MTAs were detected in at least two environments, and five were associated with multiple traits. The next step will be to validate these candidates in different genetic backgrounds to provide resources for marker-assisted breeding of faba bean yield.

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.

Effects of Broad Bean Diet on the Growth Performance, Muscle Characteristics, Antioxidant Capacity, and Intestinal Health of Nile Tilapia (Oreochromis niloticus)

Four crisping diets were designed to conduct a feeding experiment to investigate the use of broad bean in the formulated feed of Nile tilapia and optimize its use. The growth performance, muscle characteristics, antioxidant capacity, and intestinal health of Nile tilapia with an initial body weight of 617.32 ± 1.64 g were evaluated after being fed with different diets for 90 days. The results showed no adverse effect on the growth performance of Nile tilapia fed with broad bean diets. Contrastingly, some improvements were found in WGR and SGR, but a lower FCR was obtained. The supplementation of broad beans weakened the antioxidant capacity of fish but did not influence liver health and the immune system. Increasing the amount of broad bean addition can increase muscle quality values, and an embrittling functional package being added to the diet can also improve muscle hardness, adhesiveness, and chewiness of Nile tilapia muscle. In addition, the crisping functional package can be applied to tilapia crisping formulated feed, which helps to improve the integrity of the intestinal tissue structure and optimize the intestinal microbiota of Nile tilapia. The final achievement of this study is to provide a theoretical reference for optimizing the breeding technology of crispy Nile tilapia and developing a specialized crisping diet for the species.

Investigation of the nutritional quality of raw and processed Canadian faba bean (Vicia faba L.) flours in comparison to pea and soy using a human in vitro gastrointestinal digestion model

Faba bean is an ancient legume that is regaining interest due to its environmental and nutritional benefits. Very little is known on the protein quality of the new faba bean varieties. In this study, the digestibility and the Digestible Indispensable Amino Acid Score (DIAAS) of the protein quality of three Canadian faba bean varieties (Fabelle, Malik and Snowbird) were compared to pea and soy using the harmonized in vitro digestion procedure developed by the International Network of Excellence on the Fate of Food in the Gastrointestinal Tract (INFOGEST). The impact of boiling on the nutritional quality of faba bean flours was also ascertained. Protein content in faba bean (28.7-32.5%) was lower than defatted soy (56.6%) but higher than pea (24.2%). Total phenolics and phytate content were higher (p < 0.05) in faba bean (2.1-2.4 mg/g and 11.5-16.4 mg/g respectively) and soy (2.4 mg/g and 19.8 mg/g respectively) comparatively to pea (1.3 mg/g and 8.9 mg/g). Trypsin inhibitor activity was significantly higher (p < 0.05) in soy (15.4 mg/g) comparatively to pea (0.7 mg/g) and faba bean (0.8-1.1 mg/g). The digestibility of free amino acids of raw faba bean flours ranged from 31 to 39% while the digestibility of total amino acids ranged from 38 to 39%. The in vitro Digestible Indispensable Amino Acid Score (IV-DIAAS) of raw faba bean flours ranged from 13 to 16 (when calculated based on free amino acid digestibility) to 32-38 (when calculated based on total amino acid digestibility) and was in a similar range to pea (13-31) and soy (11-40). Boiling modified the protein electrophoretic profile and decreased trypsin inhibitor activity (30-86% reduction), while total phenolics and phytate content were unaffected. The IV-DIAAS significantly decreased in all boiled legumes, possibly due to an increased protein aggregation leading into a lower protein digestibility (18-32% reduction). After boiling, the nutritional quality of faba bean was significantly lower (p < 0.05) than soy, but higher than pea. Our results demonstrate that faba bean has a comparable protein quality than other legumes and could be used in similar food applications.

Applications of Enzyme Technology to Enhance Transition to Plant Proteins: A Review

As the plant-based food market grows, demand for plant protein is also increasing. Proteins are a major component in foods and are key to developing desired structures and textures. Seed storage proteins are the main plant proteins in the human diet. They are abundant in, for example, legumes or defatted oilseeds, which makes them an excellent candidate to use in the development of novel plant-based foods. However, they often have low and inflexible functionalities, as in nature they are designed to remain densely packed and inert within cell walls until they are needed during germination. Enzymes are often used by the food industry, for example, in the production of cheese or beer, to modify ingredient properties. Although they currently have limited applications in plant proteins, interest in the area is exponentially increasing. The present review first considers the current state and potential of enzyme utilization related to plant proteins, including uses in protein extraction and post-extraction modifications. Then, relevant opportunities and challenges are critically discussed. The main challenges relate to the knowledge gap, the high cost of enzymes, and the complexity of plant proteins as substrates. The overall aim of this review is to increase awareness, highlight challenges, and explore ways to address them.

Legume protein/polysaccharide food hydrogels: Preparation methods, improvement strategies and applications

For the development of innovative foods and nutritional fortification, research into food gel is essential. As two types of rich natural gel material, both legume proteins and polysaccharides have high nutritional value and excellent application potential, attracting wide attention worldwide. Research has focused on combining legume proteins with polysaccharides to form hybrid hydrogels as their combinations show improved texture and water retention compared to single legume protein or single polysaccharide gels, and these properties can be tailored for specific applications. This article reviews hydrogels of common legume proteins and discusses heat induction, pH induction, salt ion induction, and enzyme-induced assembly of legume protein/polysaccharide mixtures. The applications of these hydrogels in fat replacement, satiety enhancement, and delivery of bioactive ingredients are discussed. Challenges for future work are also highlighted.

Green Alternatives as Antimicrobial Agents in Mitigating Periodontal Diseases: A Narrative Review

Periodontal diseases and dental caries are the most common infectious oral diseases impacting oral health globally. Oral cavity health is crucial for enhancing life quality since it serves as the entranceway to general health. The oral microbiome and oral infectious diseases are strongly correlated. Gram-negative anaerobic bacteria have been associated with periodontal diseases. Due to the shortcomings of several antimicrobial medications frequently applied in dentistry, the lack of resources in developing countries, the prevalence of oral inflammatory conditions, and the rise in bacterial antibiotic resistance, there is a need for reliable, efficient, and affordable alternative solutions for the prevention and treatment of periodontal diseases. Several accessible chemical agents can alter the oral microbiota, although these substances also have unfavorable symptoms such as vomiting, diarrhea, and tooth discoloration. Natural phytochemicals generated from plants that have historically been used as medicines are categorized as prospective alternatives due to the ongoing quest for substitute products. This review concentrated on phytochemicals or herbal extracts that impact periodontal diseases by decreasing the formation of dental biofilms and plaques, preventing the proliferation of oral pathogens, and inhibiting bacterial adhesion to surfaces. Investigations examining the effectiveness and safety of plant-based medicines have also been presented, including those conducted over the past decade.

Nutritional and pharmacological potentials of orphan legumes: Subfamily faboideae

Legumes are a major food crop in many developing nations. However, orphan or underutilized legumes are domesticated legumes that have valuable properties but are less significant than main legumes due to use and supply restrictions. Compared to other major legumes, they are better suited to harsh soil and climate conditions, and their great tolerance to abiotic environmental circumstances like drought can help to lessen the strains brought on by climate change. Despite this, their economic significance in international markets is relatively minimal. This article is aimed at carrying out a comprehensive review of the nutritional and pharmacological benefits of orphan legumes from eight genera in the sub-family Faboidea, namely Psophocarpus Neck. ex DC., Tylosema (Schweinf.) Torre Hillc., Vigna Savi., Vicia L., Baphia Afzel. ex G. Lodd., Mucuna Adans, Indigofera L. and Macrotyloma (Wight & Arn.) Verdc, and the phytoconstituents that have been isolated and characterized from these plants. A literature search was conducted using PubMed, Google Scholar, and Science Direct for articles that have previously reported the relevance of underutilized legumes. The International Union for Conservation of Nature (IUCN) red list of threatened species was also conducted for the status of the species. References were scrutinized and citation searches were performed on the study. The review showed that many underutilized legumes have a lot of untapped potential in terms of their nutritional and pharmacological activities. The phytoconstituents from plants in the subfamily Faboideae could serve as lead compounds for drug discovery for the treatment of a variety of disorders, indicating the need to explore these plant species.

The giant diploid faba genome unlocks variation in a global protein crop

Increasing the proportion of locally produced plant protein in currently meat-rich diets could substantially reduce greenhouse gas emissions and loss of biodiversity1. However, plant protein production is hampered by the lack of a cool-season legume equivalent to soybean in agronomic value2. Faba bean (Vicia faba L.) has a high yield potential and is well suited for cultivation in temperate regions, but genomic resources are scarce. Here, we report a high-quality chromosome-scale assembly of the faba bean genome and show that it has expanded to a massive 13 Gb in size through an imbalance between the rates of amplification and elimination of retrotransposons and satellite repeats. Genes and recombination events are evenly dispersed across chromosomes and the gene space is remarkably compact considering the genome size, although with substantial copy number variation driven by tandem duplication. Demonstrating practical application of the genome sequence, we develop a targeted genotyping assay and use high-resolution genome-wide association analysis to dissect the genetic basis of seed size and hilum colour. The resources presented constitute a genomics-based breeding platform for faba bean, enabling breeders and geneticists to accelerate the improvement of sustainable protein production across the Mediterranean, subtropical and northern temperate agroecological zones.

Genetic and Metabolite Variability among Commercial Varieties and Advanced Lines of Vicia faba L

Vicia faba L. (faba bean) is one of the most promising pulse crops due to its nutritional value and high nitrogen fixation capacity. The aim of the present study was to compare the genetic diversity and the seed metabolite profiles of five genetic materials of faba bean. Specifically, three newly developed advanced lines (KK18, KK14 and KK10) and two commercial cultivars (POLIKARPI and TANAGRA), were evaluated for this purpose. Genetic diversity among populations was assessed by SCoT molecular markers. Through UPGMA dendrogram, genetic distances between populations were estimated. Untargeted metabolomics analysis of the seeds was performed employing GC/EI/MS. The cultivar POLYKARPI exhibited the highest polymorphism. All varieties showed a higher within-cultivars and advanced lines variability than between. POLYKARPI and KK14 had the lowest genetic distances, while KK18 and TANAGRA presented the highest ones. The advanced line KK18 displayed the best nutritional profile, the highest concentration of desirable metabolites (lactic acid and trehalose), the lowest concentration of anti-nutritional factors (oxalic acid) and the lowest concentration of saturated fatty acids (palmitic and stearic acid). According to the results of the present study, KK18 line is a very promising material for further exploration and utilization in breeding programs.

Protein Nanofibrils from Fava Bean and Its Major Storage Proteins: Formation and Ability to Generate and Stabilise Foams

Protein nanofibrils (PNFs) have potential for use in food applications as texture inducers. This study investigated the formation of PNFs from protein extracted from whole fava bean and from its two major storage proteins, globulin fractions 11S and 7S. PNFs were formed by heating (85 °C) the proteins under acidic conditions (pH 2) for 24 h. Thioflavin T fluorescence and atomic force microscopy techniques were used to investigate PNF formation. The foaming properties (capacity, stability, and half-life) were explored for non-fibrillated and fibrillated protein from fava bean, 11S, and 7S to investigate the texturing ability of PNFs at concentrations of 1 and 10 mg/mL and pH 7. The results showed that all three heat-incubated proteins (fava bean, 11S, and 7S) formed straight semi-flexible PNFs. Some differences in the capacity to form PNFs were observed between the two globulin fractions, with the smaller 7S protein being superior to 11S. The fibrillated protein from fava bean, 11S, and 7S generated more voluminous and more stable foams at 10 mg/mL than the corresponding non-fibrillated protein. However, this ability for fibrillated proteins to improve the foam properties seemed to be concentration-dependent, as at 1 mg/mL, the foams were less stable than those made from the non-fibrillated protein.

Soybean genetic resources contributing to sustainable protein production

KEY MESSAGE

Genetic resources contributes to the sustainable protein production in soybean. Soybean is an important crop for food, oil, and forage and is the main source of edible vegetable oil and vegetable protein. It plays an important role in maintaining balanced dietary nutrients for human health. The soybean protein content is a quantitative trait mainly controlled by gene additive effects and is usually negatively correlated with agronomic traits such as the oil content and yield. The selection of soybean varieties with high protein content and high yield to secure sustainable protein production is one of the difficulties in soybean breeding. The abundant genetic variation of soybean germplasm resources is the basis for overcoming the obstacles in breeding for soybean varieties with high yield and high protein content. Soybean has been cultivated for more than 5000 years and has spread from China to other parts of the world. The rich genetic resources play an important role in promoting the sustainable production of soybean protein worldwide. In this paper, the origin and spread of soybean and the current status of soybean production are reviewed; the genetic characteristics of soybean protein and the distribution of resources are expounded based on phenotypes; the discovery of soybean seed protein-related genes as well as transcriptomic, metabolomic, and proteomic studies in soybean are elaborated; the creation and utilization of high-protein germplasm resources are introduced; and the prospect of high-protein soybean breeding is described.

Seed Development and Protein Accumulation Patterns in Faba Bean (Vicia faba, L.)

A major objective in faba bean breeding is to improve its protein quality by selecting cultivars with enhanced desirable physicochemical properties. However, the protein composition of the mature seed is determined by a series of biological processes occurring during seed growth. Thus, any attempt to explain the final seed composition must consider the dynamics of the seed proteome during seed development. Here, we investigated the proteomic profile of developing faba bean seeds across 12 growth stages from 20 days after pollination (DAP) to full maturity. We analyzed trypsin-digested total protein extracts from the seeds at different growth stages by liquid chromatography-tandem mass spectrometry (LC-MS/MS), identifying 1217 proteins. The functional clusters of these proteins showed that, in early growth stages, proteins related to cell growth, division, and metabolism were most abundant compared to seed storage proteins that began to accumulate from 45 DAP. Moreover, label-free quantification of the relative abundance of seed proteins, including important globulin proteins, revealed several distinct temporal accumulation trends among the protein classes. These results suggest that these proteins are regulated differently and require further understanding of the impact of the different environmental stresses occurring at different grain filling stages on the expression and accumulation of these seed storage proteins.

Amino acid transporter (AAT) gene family in Tartary buckwheat (Fagopyrum tataricum L. Gaertn.): Characterization, expression analysis and functional prediction

Tartary buckwheat (Fagopyrum tataricum L. Gaertn., TB) is an ancient minor crop and an important food source for humans to supplement nutrients such as flavonoids and essential amino acids. Amino acid transporters (AATs) play critical roles in plant growth and development through the transport of amino acids. In this study, 104 AATs were identified in TB genome and divided into 11 subfamilies by phylogenetic relationships. Tandem and segmental duplications promoted the expansion of FtAAT gene family, and the variations of gene sequence, protein structure and expression pattern were the main reasons for the functional differentiation of FtAATs. Based on RNA-seq and qRT-PCR, the expression patterns of FtAATs in different tissues and under different abiotic stresses were analyzed, and several candidate FtAATs that might affect grain development and response to abiotic stresses were identified, such as FtAAP12 and FtCAT7. Finally, combined with the previous studies, the expression patterns and phylogenetic relationships of AATs in multiple species, the functions of multiple high-confidence FtAAT genes were predicted, and the schematic diagram of FtAATs in TB was initially drawn. Overall, this work provided a framework for further functional analysis of FtAAT genes and important clues for the improvement of TB quality and stress resistance.

Ensuring Global Food Security by Improving Protein Content in Major Grain Legumes Using Breeding and 'Omics' Tools

Grain legumes are a rich source of dietary protein for millions of people globally and thus a key driver for securing global food security. Legume plant-based 'dietary protein' biofortification is an economic strategy for alleviating the menace of rising malnutrition-related problems and hidden hunger. Malnutrition from protein deficiency is predominant in human populations with an insufficient daily intake of animal protein/dietary protein due to economic limitations, especially in developing countries. Therefore, enhancing grain legume protein content will help eradicate protein-related malnutrition problems in low-income and underprivileged countries. Here, we review the exploitable genetic variability for grain protein content in various major grain legumes for improving the protein content of high-yielding, low-protein genotypes. We highlight classical genetics-based inheritance of protein content in various legumes and discuss advances in molecular marker technology that have enabled us to underpin various quantitative trait loci controlling seed protein content (SPC) in biparental-based mapping populations and genome-wide association studies. We also review the progress of functional genomics in deciphering the underlying candidate gene(s) controlling SPC in various grain legumes and the role of proteomics and metabolomics in shedding light on the accumulation of various novel proteins and metabolites in high-protein legume genotypes. Lastly, we detail the scope of genomic selection, high-throughput phenotyping, emerging genome editing tools, and speed breeding protocols for enhancing SPC in grain legumes to achieve legume-based dietary protein security and thus reduce the global hunger risk.

Genomic regions associated with chocolate spot (Botrytis fabae Sard.) resistance in faba bean (Vicia faba L.)

Chocolate spot (CS), caused by Botrytis fabae Sard., is an important threat to global faba bean production. Growing resistant faba bean cultivars is, therefore, paramount to preventing yield loss. To date, there have been no reported quantitative trait loci (QTL) associated with CS resistance in faba bean. The objective of this study was to identify genomic regions associated with CS resistance using a recombinant inbred line (RIL) population derived from resistant accession ILB 938. A total of 165 RILs from the cross Mélodie/2 × ILB 938/2 were genotyped and evaluated for CS reactions under replicated controlled climate conditions. The RIL population showed significant variation in response to CS resistance. QTL analysis identified five loci contributing to CS resistance on faba bean chromosomes 1 and 6, accounting for 28.4% and 12.5%, respectively, of the total phenotypic variance. The results of this study not only provide insight into disease-resistance QTL, but also can be used as potential targets for marker-assisted breeding in faba bean genetic improvement for CS resistance.

Supplementary Information

The online version contains supplementary material available at 10.1007/s11032-022-01307-7.

In Silico Analysis and Functional Characterization of Antimicrobial and Insecticidal Vicilin from Moth Bean (Vigna aconitifolia (Jacq.) Marechal) Seeds

Vicilin has nutraceutical potential and different noteworthy medicative health-promoting biotic diversions, and it is remarkable against pathogenic microorganisms and insects. In this study, Vigna aconitifolia vicilin (VacV) has been identified and characterized from the seed of Vigna aconitifolia (Jacq.) Marechal (Moth beans). LC-MS/MS analysis of VacV provided seven random fragmented sequences comprising 238 residues, showing significant homology with already reported Vigna radiata vicilin (VraV). VacV was purified using ammonium sulfate precipitation (60%) followed by size exclusion chromatography on Hi-Load 16/60 Superdex 200 pg column and anion-exchange chromatography (Hi trap Q FF column). Purified VacV showed a major ~50 kDa band and multiple lower bands on 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) under both reduced and non-reduced conditions. After all, a three-dimensional molecular structure of VacV was predicted, which showed β-sheeted molecular conformation similar to crystallographic structure of VraV. All Vicilins from V. aconitifolia and other plants were divided into six sub-groups by phylogenetic analysis, and VacV shared a high degree of similarity with vicilins of Vigna radiata, Pisum sativum, Lupinus albus, Cicer arietinum and Glycine max. Additionally, VacV (20 μg) has significant growth inhibition against different pathogenic bacteria along strong antifungal activity (50 μg). Likewise, VacV (3.0 mg) produced significant growth reduction in Rice Weevil Sitophilus oryzae larvae after 9 days compared with control. Furthermore, by using MMT assay, the cytotoxicity effect of VacV on the growth of HepG2 liver cancerous cells was tested. VacV showed cytotoxicity against the HepG-2 line and the acquired value was 180 µg after 48 h. Finally, we performed molecular docking against caspase-3 protein (PDB ID: 3DEI) for VacV bioactive receptor interface residues. Hence, our results reveal that VacV, has nutraceutical potential and moth beans can be used as a rich resource of functional foods.

Using Mid-IR spectroscopy (ATR-FTIR) as a fast analytical tool to reveal association between protein spectral profiles and metabolizable protein supply, protein rumen degradation characteristics and estimated intestinal protein digestion before and after rumen incubation of faba bean partitions and faba bean silage

To our knowledge, there is little research done in using vibrational MID-IR molecular spectroscopy- attenuated total reflectance - Fourier transform infrared spectroscopy (ATR-FTIR) for ruminant system study. The objective of this study was to use ATR-FTIR as a fast analytical tool to reveal association between protein molecular structure in faba and metabolizable protein supply and nutrient delivery, and to explore the relationship between protein molecular structure in original and ruminal degraded residue and in situ rumen protein degradation and protein metabolism characteristics of faba bean samples (whole crop, stem, leaf, whole pods, and faba silage). The experiment for ruminant nutrition research was RCBD. Fourier transform Infrared (FTIR) spectra of faba samples before and after 12 and 24 h rumen incubations were collected with JASCO FT/IR-4200 with ATR at mid-IR range (ca. 4000-700 cm^-1) with 128 scans and at 4 cm^-1 resolution. The univariate molecular spectral analysis was carried using OMNIC software. Protein related spectral parameters before and after rumen degradation included amide region (ca. 1730-1480 cm^-1), amide I region (ca. 1713-1558 cm^-1) and amide II region (ca. 1558-1485 cm^-1). Within amide I region, α-helix (ca. 1644 cm^-1) and β-sheet (ca. 1630 cm^-1) were studied. The results showed that ATR-FTIR protein molecular spectral features were significantly different before and after rumen incubation. Protein availability and digestion characteristic are mainly determined by original ATR-FTIR spectral profiles. Total truly digestible protein value (DVE) of faba partitions could be predicted with this equation: DVE (g/kg DM) = 1207.7 HAII12 + 228.7 alpha_beta24 - 310.8 (with R-square = 0.94, RSD = 8.06, model P < 0.001). The study shows that vibrational MID-IR molecular spectroscopy (ATR-FTIR) show a high potential to be a fast analytical tool to predict nutrient delivery.

Physical Properties of Extrudates with Fibrous Structures Made of Faba Bean Protein Ingredients Using High Moisture Extrusion

Faba bean is a potential ingredient due to its high protein yield and its possible cultivation in colder climate regions. In this study, meat analogues made from faba bean protein isolate (FPI) and concentrate (FPC) blends were produced using high moisture extrusion. The aim of this study was to investigate the effect of the FPI content (FPIc), feed water content (FWC), and temperature of the long cooling die (LT) during extrusion on the mechanical and physicochemical properties as well as on the structure of the meat analogues. Increased FPIc resulted in higher values in hardness, gumminess, chewiness, and cutting strengths as well as in darker colour and decreased water absorption capacity. The effect of increased FWC on these properties was weaker and the opposite. Images from microtomography revealed that higher FPIc led to a less organised fibrous structure. In conclusion, fibrous structures can be achieved by utilising a mixture of faba bean protein ingredients, and a higher FPC content seemed to promote fibre formation in the meat analogue.

Crosstalk during the Carbon-Nitrogen Cycle That Interlinks the Biosynthesis, Mobilization and Accumulation of Seed Storage Reserves

Carbohydrates are the major storage reserves in seeds, and they are produced and accumulated in specific tissues during the growth and development of a plant. The storage products are hydrolyzed into a mobile form, and they are then translocated to the developing tissue following seed germination, thereby ensuring new plant formation and seedling vigor. The utilization of seed reserves is an important characteristic of seed quality. This review focuses on the seed storage reserve composition, source–sink relations and partitioning of the major transported carbohydrate form, i.e., sucrose, into different reserves through sucrolytic processes, biosynthetic pathways, interchanging levels during mobilization and crosstalk based on vital biochemical pathways that interlink the carbon and nitrogen cycles. Seed storage reserves are important due to their nutritional value; therefore, novel approaches to augmenting the targeted storage reserve are also discussed.

Lentil and Fava Bean With Contrasting Germination Kinetics: A Focus on Digestion of Proteins and Bioactivity of Resistant Peptides

Germination offers advantages to improve legume protein digestibility as it disintegrates seed structure and hydrolyzes proteins and anti-nutrients. Seed permeability (related to polyphenol content of seed coats) is an important factor affecting the duration of seed germination and its impact on protein digestibility and bioactivity. The objective was to compare the effect of seed germination on protease activity, structure, and proteolysis of four selected legumes with contrasting seed coat polyphenol profiles (gray zero-tannin lentil [GZL], beluga lentil [BL], and dehulled red lentil [DL]; and zero tannin/low vicine-convicine fava bean [ZF]). Protein hydrolysis was characterized during germination and digestion with respect to proteins, peptides, and free amino acids (FAAs). In vitro antihypertensive and antioxidant activities of digests were investigated, and the peptidomic characterization [high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS)] and identification of bioactive fragments in intestinal digests were performed. Regardless of the seed type, germination increased protease activity and reduced the levels of phytic acid, trypsin inhibitors, and tannins (only in BL). A significant proteolysis of the 7S and 11S globulins and a concomitant increase of peptides and FAAs were observed in all sprouted legumes. Digestion kinetics in sprouts revealed a faster generation of FAAs and peptides than in dry seeds, with changes being more evident for DL, associated with a faster imbibition, germination, and sprout growth. In contrast, BL sprouts showed the lowest protein digestibility, likely due to a lower protease activity, seed structure disintegration, and higher anti-nutrient levels in comparison to GZL, DL, and ZF. Moreover, the digestion of sprouts resulted in a higher number of resistant peptides in DL and ZF that matched with previously reported bioactive sequences, suggesting a promising health potential of legume sprouts that was confirmed in vitro. The results suggested that the germination process improved protein digestibility and the health-promoting potential of lentil and fava bean proteins although these changes were more evident in DL due to its rapid imbibition, faster germination, and sprout development. This study will provide important information for either plant breeders to develop legume varieties with permeable seed coats or food producers that could use dehulled seeds for efficient production of sprouts as sustainable food sources of plant proteins with improved nutritional and healthy properties.

Current Perspectives on Reducing the β-ODAP Content and Improving Potential Agronomic Traits in Grass Pea (Lathyrus sativus L.)

Grass pea is well-established as one of the most resilient and versatile crops that can thrive under extreme climatic circumstances such as cold, heat, drought, salt-affected soils, submergence, and excessive rainfall along with resistance to several diseases and pests. However, despite the awareness of its virtues, its cultivation globally has decreased recently owing to the presence of a neurotoxin, β-N-oxalyl-L-α, β-diaminopropionic acid (β-ODAP), in the seedlings and seeds of this legume, which has been reported to cause neurolathyrism, a non-reversible neurological disorder in humans and animals. Significant repositories of Lathyrus germplasm are available across countries that have provided access to a wide range of agro-morphological traits as well as the low β ODAP content. Efforts have been made worldwide to use these germplasms for the genetic enhancement of grass pea to make this food safe for human consumption. Efforts on molecular breeding of this crop are also lagging. However, during the last decade, the research scenario has changed with some efforts being made toward improving this climate resilient pulse in terms of genomic resources. Molecular markers have also been used to evaluate the interspecific diversity as well as the phylogenetic relationship among the species and mapping studies. Intron-targeted amplified polymorphic, genomic simple sequence repeat, resistance genes analogs, and disease resistance markers developed for other legume species have been successfully cross-amplified in grass pea. Transcriptomic studies have recently been undertaken on grass pea by deploying several second-generation sequencing techniques. In addition, a few studies have attempted to unveil the genes and the underlying mechanism conferring biotic and abiotic stress or regulating the pathway of β-ODAP in grass pea. Proteomics has accelerated the identification studies on differential proteomes in response to salinity and low-temperature stress conditions for unveiling the common signaling pathways involved in mitigating these abiotic stresses and in discovering differentially regulated proteins. In grass pea, a metabolomics approach has been used to identify the metabolic processes associated with β-ODAP synthesis. Genome sequencing of grass pea is under way which is expected to be vital for whole-genome re-sequencing and gene annotation toward the identification of genes with novel functions. Recently, a draft genome sequence of grass pea was developed, and some efforts are underway to re-sequence a diverse panel of grass pea comprising 384 germplasm lines. Owing to the scantiness of a successful transformation protocol, research on the application of modern approaches of genome editing like the Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) or CRISPR-associated protein 9 (CRISPR/Cas9) system for the engineering of signaling pathways or regulatory mechanisms seeks immediate attention to reduce the β-ODAP content in seeds and to improve the potential agronomic traits in grass pea.

Recent advances in faba bean genetic and genomic tools for crop improvement

Faba bean (Vicia faba L.), a member of the Fabaceae family, is one of the important food legumes cultivated in cool temperate regions. It holds great importance for human consumption and livestock feed because of its high protein content, dietary fibre, and nutritional value. Major faba bean breeding challenges include its mixed breeding system, unknown wild progenitor, and genome size of ~13 Gb, which is the largest among diploid field crops. The key breeding objectives in faba bean include improved resistance to biotic and abiotic stress and enhanced seed quality traits. Regarding quality traits, major progress on reduction of vicine-convicine and seed coat tannins, the main anti-nutritional factors limiting faba bean seed usage, have been recently achieved through gene discovery. Genomic resources are relatively less advanced compared with other grain legume species, but significant improvements are underway due to a recent increase in research activities. A number of bi-parental populations have been constructed and mapped for targeted traits in the last decade. Faba bean now benefits from saturated synteny-based genetic maps, along with next-generation sequencing and high-throughput genotyping technologies that are paving the way for marker-assisted selection. Developing a reference genome, and ultimately a pan-genome, will provide a foundational resource for molecular breeding. In this review, we cover the recent development and deployment of genomic tools for faba bean breeding.

Nutritive value of faba bean (Vicia faba L.) as a feedstuff resource in livestock nutrition: A review

The review evaluates faba bean (Vicia faba L.; FB) seeds relative to their nutritional composition, their content of antinutritional factors, and their impact on animal performance. The literature indicates that FB plant is a cool-season, annual grain legume that grows the best in cool and humid conditions. Its seeds are rich in protein, energy, and mineral compounds and have particularly high unsaturated fatty acid levels. However, FB seeds also contain various proportions of antinutritional factors (ANFs) that can interfere with nutrient utilization in nonruminants. The various processing methods are efficient in either reducing or inactivating the ANFs of FB seeds, with extrusion treatment offering the most effective method of improving apparent nutrient and energy digestibility of nonruminants. In vivo studies on ruminants, pigs, poultry, and fishes reveal that FB seeds have the potential to be used as a substitute for soybean meal and/or cereal seeds in livestock diets in order to support milk, meat, and/or egg production.

Functional and Rheological Properties of Vicia faba L. Protein Isolates

A protein isolate (85.5%) was obtained from the Vicia faba L. seeds. The main protein fraction, typical for the seeds of this plant, was found to be most numerous: Legumin (35 kDa) and Vicilin (45 kDa). The hydrodynamic and surface properties of isolate aqueous solutions were studied with the help of dynamic light scattering, ζ-potential, and tensometry in a wide range of concentrations and pH conditions. Selected functional properties, like foaming and emulsifying abilities, were studied. An increase of water solubility was shown with a raising pH, as well as a water holding capacity (WHC). The protein isolate showed a tendency to decrease the surface tension of water solutions, with high hydrophobicity and a negative charge of the isolate enhancing the foaming and emulsifying properties. The analysis of the concentration and the pH influence on selected functional properties indicated alkaline conditions as favorable for good foaming and emulsifying properties of the isolate and affected on their rheological properties.

Fava bean (Vicia faba L.) for food applications: From seed to ingredient processing and its effect on functional properties, antinutritional factors, flavor, and color

The food industry, along with the consumers, is interested in plant-based diet because of its health benefits and environmental sustainability. Vicia faba L. (V. faba) is a promising source of pulse proteins for the human diet and can yield potential nutritional and functional ingredients, namely, flours, concentrates, and isolates, which are relevant for industrial food applications. Different processes produce and functionalize V. faba ingredients relevant for industrial food applications, along with various alternatives within each unit operation used in their production. Processing modifies functional properties of the ingredients, which can occur by (i) changing in overall nutritional composition after processing steps and/or (ii) modifying the structure and conformation of protein and of other components present in the ingredients. Furthermore, V. faba limitations due to off-flavor, color, and antinutritional factors are influenced by ingredient production and processing that play a significant role in their consumer acceptability in foods. This review attempts to elucidate the influence of different ways of processing on the functional, sensory, and safety aspects of V. faba L. ingredients, highlighting the need for further research to better understand how the food industry could improve their utilization in the market.

Simultaneous changes in seed size, oil content and protein content driven by selection of SWEET homologues during soybean domestication

Soybean accounts for more than half of the global production of oilseed and more than a quarter of the protein used globally for human food and animal feed. Soybean domestication involved parallel increases in seed size and oil content, and a concomitant decrease in protein content. However, science has not yet discovered whether these effects were due to selective pressure on a single gene or multiple genes. Here, re-sequencing data from >800 genotypes revealed a strong selection during soybean domestication on GmSWEET10a. The selection of GmSWEET10a conferred simultaneous increases in soybean-seed size and oil content as well as a reduction in the protein content. The result was validated using both near-isogenic lines carrying substitution of haplotype chromosomal segments and transgenic soybeans. Moreover, GmSWEET10b was found to be functionally redundant with its homologue GmSWEET10a and to be undergoing selection in current breeding, leading the the elite allele GmSWEET10b, a potential target for present-day soybean breeding. Both GmSWEET10a and GmSWEET10b were shown to transport sucrose and hexose, contributing to sugar allocation from seed coat to embryo, which consequently determines oil and protein contents and seed size in soybean. We conclude that past selection of optimal GmSWEET10a alleles drove the initial domestication of multiple soybean-seed traits and that targeted selection of the elite allele GmSWEET10b may further improve the yield and seed quality of modern soybean cultivars.

Identification and Quantification of Major Faba Bean Seed Proteins

Faba bean (Vicia faba L.) holds great importance for human and animal nutrition for its high protein content. However, better understanding of its seed protein composition is required in order to develop cultivars that meet market demands for plant proteins with specific quality attributes. In this study, we screened 35 diverse Vicia faba genotypes by employing the one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (1D SDS-PAGE) method, and 35 major protein bands obtained from three genotypes with contrasting seed protein profiles were further analyzed by mass spectrometry (MS). Twenty-five of these protein bands (MW range: ∼ 9-107 kDa) had significant (p ≤ 0.05) matches to polypeptides in protein databases. MS analysis showed that most of the analyzed protein bands contained more than one protein type and, in total, over 100 proteins were identified. These included major seed storage proteins such as legumin, vicilin, and convicilin, as well as other protein classes like lipoxygenase, heat shock proteins, sucrose-binding proteins, albumin, and defensin. Furthermore, seed protein extracts were separated by size-exclusion high-performance liquid chromatography (SE-HPLC), and percentages of the major protein classes were determined. On average, legumin and vicilin/convicilin accounted for 50 and 27% of the total protein extract, respectively. However, the proportions of these proteins varied considerably among genotypes, with the ratio of legumin:vicilin/convicilin ranging from 1:1 to 1:3. In addition, there was a significant (p < 0.01) negative correlation between the contents of these major fractions (r = -0.83). This study significantly extends the number of identified Vicia faba seed proteins and reveals new qualitative and quantitative variation in seed protein composition, filling a significant gap in the literature. Moreover, the germplasm and screening methods presented here are expected to contribute in selecting varieties with improved protein content and quality.