Search Results (46)

Soybean is the dominant source of plant-derived protein, yet improving seed protein content without reducing yield remains a breeding challenge. While the phytohormone auxin is well-established as a crucial regulator of seed development, its precise role in metabolic homeostasis governing protein accumulation remains largely unexplored. Here, we show that disrupting auxin conjugation via CRISPR-Cas9-generated gh3Q (GH3 quadruple) mutants elevates free auxin levels and is associated with increased seed size, hundred-seed weight, and protein content. Time-course transcriptome profiling of seed coats and embryos identified the R6-stage seed coat as a pivotal tissue for protein accumulation, where seven key seed storage protein genes (2S albumin and 11S glycinin family members) were significantly up-regulated. Weighted gene co-expression network analysis (WGCNA) further uncovered auxin polar transport modules and novel hub genes that are co-expressed with potentially link auxin signaling to protein storage pathways. These findings suggest that auxin homeostasis may link phytohormone signaling and metabolism allocation in soybean seed development. Our study provides genetic targets and a regulatory network for developing high-protein soybean varieties. Full article

Soybean (Glycine max L. Merr.) is one of the most important legume crops globally, providing high-quality plant protein and oil for humans and livestock, and playing a crucial role in nitrogen fixation within agricultural ecosystems. The seeds contain about 35–40% protein by dry weight, with 65–80% of this being seed storage proteins (SSPs). These proteins mainly consist of 11S globulin (glycinin) and 7S β-conglycinin, which accumulate significantly in protein bodies during seed development, providing essential nitrogen and amino acids for seed germination and early seedling growth. Additionally, the composition and structure of SSPs directly determine the nutritional value, processing functionalities (such as emulsification, gelation, and solubility), and potential allergenicity of soybean products. In this study, we conducted a detailed analysis of the structural characteristics, chromosomal localization, phylogenetic relationships, and tissue expression patterns of members of the soybean Gy gene family, laying a theoretical foundation for further exploration of the biological functions of Gy genes in soybeans. We performed comprehensive genomic identification, expression analysis, and subcellular localization of the soybean Gy gene family. The results showed that the seven soybean Gy genes are unevenly distributed across different chromosomes and exhibit distinct expression patterns in soybean seeds, suggesting they may have different roles during seed development. Subcellular localization experiments indicated that the GmGy1 gene might play an important role during seed development. These findings provide significant insights into the functions of the Gy gene family in soybean growth and development and offer potential candidate gene targets for soybean molecular breeding. Full article

Soybean meal (SBM) is a foundational protein source, but its industrial application is constrained by a complex matrix of anti-nutritional factors (ANFs). This review provides a critical synthesis of the biochemical transition from raw SBM to fermented SBM (FSBM), focusing on the synergistic mechanisms of fungal and bacterial co-fermentation. We identify that the efficacy of FSBM is primarily driven by the microbial proteolysis of glycinin into low-molecular-weight bioactive peptides (<1000 Da). These peptides serve as the primary drivers for improved intestinal morphology (increased villus height) and the modulation of the gut microbiota, providing a mechanistic basis for reported probiotic effects. Furthermore, we establish that the 5–10% improvement in the feed conversion ratio (FCR) documented for swines mathematically offsets the processing premium of fermentation. However, critical gaps remain in the standardization of solid-state fermentation (SSF) protocols, specifically regarding the selection of fungal (Aspergillus) and bacterial (Bacillus or Lactobacillus) strains, whose distinct metabolic pathways significantly diversify the functional profile of the resulting FSBM. Full article

Soybean flour (SF) allergy is a common food allergy reaction that significantly impacts patients’ daily diet and quality of life. This study used a combination of physical ball milling technology and γ-Aminobutyric acid (GABA) treatment to reduce the antigenicity of SF. When the material ball ratio was 1:14 (w/w), SF after ball milling treatment exhibited the smallest average particle size, and the highest solubility, bulk density, and antioxidant capacity. The functional properties of SF were further enhanced by adding GABA. Meanwhile, SF with 0.4% added GABA exhibited the smallest average particle size, the highest solubility, and the highest antioxidant capacity. The antigen content in soybean flour was determined using the soy glycinin ELISA kit and β-conglycinin ELISA kit. Compared with the original SF, the antigen contents of globulin and β-conglycinin decreased by 89.11% and 89.61%, respectively, in SF with the addition of 0.4% GABA after ball milling treatment. These results indicate that the addition of GABA not only further optimizes the solubility and antioxidant properties of SF, but also significantly reduces its antigen content. This study developed a combined treatment method to reduce allergenicity, overcoming the limitations of a single physical or biological treatment and providing a new technical approach for developing soybean flour products with low allergenicity. Full article

In recent years, sustainable agricultural practices in wheat cultivation have garnered significant attention, particularly those focused on minimizing pesticide and herbicide usage to safeguard the environment. One effective approach is green manuring, which entails rotating wheat with crops such as soybean and mustard to harness their natural pesticidal and herbicidal properties. While this method presents clear environmental advantages, it also poses a risk of cross-contamination, as these globally recognized allergens may unintentionally pass through wheat-based products. To protect consumers with allergies, there is an urgent need for a reliable analytical method to detect and quantify these allergenic proteins in wheat-derived foodstuffs. In this study, we assessed various protein extraction protocols to optimize the recovery of soybean and mustard allergens from wheat flour. The extracted proteins were analyzed using a bottom-up proteomics approach involving trypsin digestion, coupled with reversed-phase liquid chromatography and mass spectrometry in multiple reaction monitoring (MRM) mode. Two key allergenic proteins, Glycinin G1 and 11S Globulin, were selected as representative for soybean and mustard, respectively. The identified quantifier marker of Glycinin G1 was VLIVPQNFVVAAR (m/z 713.431²⁺), while FYLAGNQEQEFLK (m/z 793.896²⁺) and VFDGELQEGR (m/z 575.280²⁺) were designated as qualifier markers. The selection of specific marker peptides for mustard proved challenging due to the high structural similarity among proteins from Sinapis alba and other members of the Brassicaceae family. For 11S Globulin, FNTLETTLTR (m/z 598.319²⁺) was recognized as the quantifier marker, with VTSVNSYTLPILQYIR (m/z 934.019²⁺) serving as the qualifier marker. The developed method underwent thorough validation for linearity, limit of detection (LOD), limit of quantification (LOQ), recovery, repeatability, and reproducibility, as well as potential matrix and processing effects. This strategy successfully facilitated the identification and quantification of soybean and mustard allergenic proteins in complex, processed food matrices, including naturally contaminated flour and cookies. These findings enhance food safety monitoring and regulatory compliance, thereby helping to mitigate allergen-related risks in wheat-based products. Full article

Background: Soy allergy is an important nutritional and health issue that needs to be addressed. Lactic acid bacteria (LAB) fermentation is an effective approach to reduce soy protein allergy. Polysaccharides are commonly used in LAB-fermented products to enhance their textural properties. This study proposes a new strategy for developing hypoallergenic soy protein products. Methods: We prepared a soy protein isolate (SPI) through fermentation with LAB (FSPI) and with five types of polysaccharides supplementation, namely polydextrose (PDX), inulin (IN), long-chain inulin (LCIN), soluble soy polysaccharides (SSPS), and β-glucan (BG). The texture and microstructure of different samples were analyzed. Antigenicity and IgE-binding capacity were determined using ELISA. Finally, peptide sequencing was used to identify the degradation degree and frequency of allergenic epitopes. Results: Samples with added PDX (F-PDX) and IN (F-IN) exhibited lower hardness; smaller, irregular pores; and a honeycomb structure, whereas samples with SSPS (F-SSPS) and BG (F-BG) had higher hardness; large, regular pores; and strong sheet structures. The antigenicity and IgE-binding capacity of F-PDX and F-IN were lower both before and after 120 min of in vitro dynamic gastrointestinal digestion. The peptidomics results indicated that F-PDX and F-IN primarily facilitated the degradation of the glycinin G1 and G2 subunits, β-conglycinin α, and the β subunit. Moreover, it increased the frequency of destruction of allergenic epitopes, and further promoted the degradation of epitopes in the external α-helix structures of glycinin and β-conglycinin compared to FSPI. Conclusions: The addition of polysaccharides had a significant impact on the structure and allergenicity of the soy protein gel, especially PDX and IN. Full article

Carob (Ceratonia siliqua) seeds are rich in diverse bioactive compounds, including galactomannan, β-sitosterol, unsaturated fatty acids and proteins with bioactive peptides in their sequence. This study delineates the compositional characterization of six carob seed flour types derived from different production processes, providing valuable insights for designing tailored nutraceutical products based on desired bioactive compound profiles. Our analysis indicated that a higher purity of galactomannan resulted in a greater mannose/galactose ratio, which increased the linearity of the galactomannan polymer and could enhance interchain interaction, thereby increasing aggregation capacity. A higher viscosity could potentially increase the capacity of galactomannan to create satiety and lower cholesterol levels. Among the different tested flours, those whose main compound was the endosperm were optimal for containing high galactomannan content, whereas those derived from the germ were ideal for having high concentrations of fatty acids (i.e., oleic and linoleic acids) and β-sitosterol. The presence of these lipids in carob flours could offer cardiovascular and metabolic health benefits, contributing synergistically. Additionally, flours that contain the germ have beneficial peptides included in proteins like glycinin and conglutin with potential anticholesterolemic and antidiabetic properties. This work provides different methods for obtaining carob flours rich in bioactive compounds, offering the nutraceutical industry a framework to select the best option for industrial-scale production. Full article

This study investigated the impact of different preheat treatments on the emulsifying and gel textural properties of soy protein with varying 11S/7S ratios. A mixture of 7S and 11S globulins, obtained from defatted soybean meal, was prepared at different ratios. The mixed proteins were subjected to preheating (75 °C, 85 °C, and 95 °C for 5 min) or non-preheating, followed by spray drying or non-spray drying. The solubility of protein mixtures rich in the 7S fraction tended to decrease significantly after heating at 85 °C, while protein mixtures rich in the 11S fraction showed a significant decrease after heating at 95 °C. Surprisingly, the emulsion stability index (ESI) of protein mixtures rich in the 7S fraction significantly improved twofold during processing at 75 °C. This study revealed a negative correlation between the emulsifying ability of soy protein and the 11S/7S ratio. For protein mixtures rich in either the 7S or the 11S fractions, gelling proprieties as well as emulsion activity index (EAI) and ESI showed no significant changes after spray drying; however, surface hydrophobicity was significantly enhanced following heating at 85 °C post-spray drying treatment. These findings provide insights into the alterations in gelling and emulsifying properties during various heating processes, offering great potential for producing soy protein ingredients with enhanced emulsifying ability and gelling property. They also contribute to establishing a theoretical basis for the standardized production of soy protein isolate with specific functional characteristics. Full article

Food allergies are a severe burden for affected individuals and healthcare systems. To tackle the need for simple food allergen detection, we developed a system for the detection of the soy protein glycinin via a centrifugal microfluidics-assisted lateral flow immunoassay (LFIA). Glycinin is a complex allergen requiring extensive sample preparation. The presented workflow includes a manual denaturing extraction, followed by automated centrifugal microfluidic desalting, metering and detection via LFIA. The functionality of the microfluidic cassettes was tested on prototypes produced via microthermoforming before an injection molding tool was designed, which added a cylindrical lens to improve the readout. Overall, this system aims to aid in food allergen detection with high sensitivity and minimized manual steps. Full article

Soybean seeds show great potential as a safe and cost-effective host for the large-scale production of biopharmaceuticals and industrially important macromolecules. However, the yields of desired recombinant proteins in soybean seeds are usually lower than the economic threshold for their potential commercialization. Our previous study demonstrated that polypeptide fusion such as maize γ-zein or elastin-like polypeptide (ELP) could significantly increase the accumulation of foreign proteins. In the present study, a recombination strategy of polypeptide fusions (γ-zein or ELP) and suppression of intrinsic storage proteins (glycinin or conglycinin) via RNA interference was further exploited to improve the yield of the target protein in soybean seeds. Transgenic soybean plants harboring both polypeptide-fused green fluorescent protein (GFP) and glycinin/conglycinin RNAi expression cassettes were generated and confirmed by molecular analysis. The results showed that on both the glycinin and conglycinin suppression backgrounds, the average accumulation levels of recombinant zein-GFP and GFP-ELP proteins were significantly increased as compared to that of their counterparts without such suppressions in our previous study. Moreover, zein-GFP and GFP-ELP accumulation was also remarkably higher than unfused GFP on the glycinin suppression background. However, no significant differences were detected in the glycinin or conglycinin suppression backgrounds for the same polypeptide fusion constructs, though suppression of one of the storage proteins in soybean seeds led to a significant increase in the other. Additionally, the increases in the recombinant protein yield did not affect the total protein content and the protein/oil ratio in soybean seeds. Taken together, the results indicate that both the fusion of the foreign protein with polypeptide tags together with the depletion of endogenous storage proteins contributed to a higher accumulation of the recombinant proteins without affecting the total protein content or the protein/oil ratio in soybean seeds. Full article

Endoplasmic reticulum (ER) stress is a crucial factor in the pathogenesis of intestinal diseases. Soybean antigenic proteins (β-conglycinin and soy glycinin) induce hypersensitivity reactions and intestinal barrier damage. However, whether this damage is associated with ER stress, autophagy, and the gut microbiome is largely unclear. Therefore, in this study, we aimed to investigate the effect of dietary supplementation with soy glycinin (11S glycinin) and β-conglycinin (7S glycinin) on intestinal ER stress, autophagy, and flora in weaned piglets. Thirty healthy 21-day-old weaned “Duroc × Long White × Yorkshire” piglets were randomly divided into three groups and fed a basic, 7S-supplemented, or 11S-supplemented diet for one week. The results indicated that 7S/11S glycinin disrupted growth performance, damaged intestinal barrier integrity, and impaired goblet cell function in piglets (p < 0.05). Moreover, 7S/11S glycinin induced ER stress and blocked autophagic flux in the jejunum (p < 0.05) and increased the relative abundance of pathogenic flora (p < 0.01) and decreased that of beneficial flora (p < 0.05). In conclusion, 7S/11S glycinin induces intestinal ER stress, autophagic flux blockage, microbiota imbalance, and intestinal barrier damage in piglets. Full article

The aim of the study was to investigate whether the negative effects of dietary glycinin are linked to the structural integrity damage, apoptosis promotion and microbiota alteration in the intestine of orange-spotted grouper (Epinephelus coioides). The basal diet (FM diet) was formulated to contain 48% protein and 11% lipid. Fish meal was replaced by soybean meal (SBM) in FM diets to prepare the SBM diet. Two experimental diets were prepared, containing 4.5% and 10% glycinin in the FM diets (G-4.5 and G-10, respectively). Triplicate groups of 20 fish in each tank (initial weight: 8.01 ± 0.10 g) were fed the four diets across an 8 week growth trial period. Fish fed SBM diets had reduced growth rate, hepatosomatic index, liver total antioxidant capacity and GSH-Px activity, but elevated liver MDA content vs. FM diets. The G-4.5 exhibited maximum growth and the G-10 exhibited a comparable growth with that of the FM diet group. The SBM and G-10 diets down-regulated intestinal tight junction function genes (occludin, claudin-3 and ZO-1) and intestinal apoptosis genes (caspase-3, caspase-8, caspase-9, bcl-2 and bcl-xL), but elevated blood diamine oxidase activity, D-lactic acid and endotoxin contents related to intestinal mucosal permeability, as well as the number of intestinal apoptosis vs FM diets. The intestinal abundance of phylum Proteobacteria and genus Vibrio in SBM diets were higher than those in groups receiving other diets. As for the expression of intestinal inflammatory factor genes, in SBM and G-10 diets vs. FM diets, pro-inflammatory genes (TNF-α, IL-1β and IL-8) were up-regulated, but anti-inflammatory genes (TGF-β1 and IL-10) were down-regulated. The results indicate that dietary 10% glycinin rather than 4.5% glycinin could decrease hepatic antioxidant ability and destroy both the intestinal microbiota profile and morphological integrity through disrupting the tight junction structure of the intestine, increasing intestinal mucosal permeability and apoptosis. These results further trigger intestinal inflammatory reactions and even enteritis, ultimately leading to the poor growth of fish. Full article

Soybean compounds have been established to modulate inflammation, but less is known about how whole soybean compositions work together after digestion. The objective was to evaluate and compare the anti-inflammatory responses of different soybean varieties under simulated gastrointestinal digestion, with additional consideration of the glycinin:β-conglycinin ratio (GBR). Soybean colonic digests (SCD) inhibited cyclooxygenase (COX)-2 (25–82%), 5-lipoxidase (LOX) (18–35%), and inducible nitric oxide (iNOS) (8–61%). Varieties 88, GN3, and 93 were the most effective inhibitors. SCD (1 mg/mL) of varieties 81 and GN1 significantly (p < 0.05) reduced nitrite production by 44 and 47%, respectively, compared to lipopolysaccharide (LPS)-stimulated macrophages. SCD effectively reduced pro-inflammatory cytokine interleukin (IL)-6 (50 and 80% for 96 and GN1, respectively). Western blot results showed a decrease in the expression of iNOS, p65, and p50. The GBR was in the range of 0.05–1.57. Higher ratio correlated with higher production of IL-1β (r = 0.44) and tumor necrosis factor-alpha (TNF-α, r = 0.56). Inflammatory microarray results showed a significant decrease in expression of markers granulocyte-macrophage colony-stimulating factor (GM-CSF) and IL-6 in cells treated with GN1 SCD compared to LPS. The results suggested that SCD exerted its anti-inflammatory potential through nuclear factor kappa B (NF-κΒ) pathway inhibition by decreasing the levels of NF-κB-dependent cytokines and subunits, and inhibition of pro-inflammatory enzyme activity. Full article

Okara is a solid byproduct created during the processing of soy milk. The production of protein hydrolysates utilizing enzymatic tests such as papain can result in the production of bioactive peptides (BPs), which are amino acid sequences that can also be produced from the okara protein by hydrolysis. The objective of this study was to investigate the antioxidant activities of okara hydrolysates using papain, based on the in silico and in vitro assays using the papain enzyme. We found that using the in silico assessment, the antioxidant peptides can be found from the precursor (glycinin and conglycinin) in okara. When used as a protease, papain provides the maximum degree of hydrolysis for antioxidative peptides. The highest-peptide-rank peptide sequence was predicted using peptide ranks such as proline–histidine–phenylalanine (PHF), alanine–aspartic acid–phenylalanine (ADF), tyrosine–tyrosine–leucine (YYL), proline–histidine–histidine (PHH), isoleucine–arginine (IR), and serine–valine–leucine (SVL). Molecular docking studies revealed that all peptides generated from the parent protein impeded substrate access to the active site of xanthine oxidase (XO). They have antioxidative properties and are employed in the in silico approach to the XO enzyme. We also use papain to evaluate the antioxidant activity by using in vitro tests for protein hydrolysate following proteolysis. The antioxidant properties of okara protein hydrolysates have been shown in vitro, utilizing DPPH and FRAP experiments. This study suggests that okara hydrolysates generated by papain can be employed as natural antioxidants in food and for further applications, such as active ingredients for antioxidants in packaging. Full article

Solid-state fermentation is known to improve plant-based feed nutritional quality; however, the association between microbes and metabolite production in fermented feed remains unclear. We inoculated corn–soybean–wheat bran (CSW) meal feed with Bacillus licheniformis Y5-39, Bacillus subtilis B-1, and lactic acid bacteria RSG-1. Then, 16S rDNA sequencing and untargeted metabolomic profiling were applied to investigate changes in the microflora and metabolites, respectively, and their integrated correlations during fermentation were assessed. The results indicated that trichloroacetic acid soluble protein levels showed a sharp increase, while glycinin and β-conglycinin levels showed a sharp decrease in the fermented feed, as confirmed by sodium dodecyl sulfate–polyacrylamide gel electrophoresis. Pediococcus, Enterococcus, and Lactobacillus were predominant in the fermented feed. Overall, 699 significantly different metabolites were identified before and after fermentation. Arginine and proline, cysteine and methionine, and phenylalanine and tryptophan metabolism were the key pathways, with arginine and proline metabolism being the most important pathway in the fermentation process. By analyzing the correlation between the microbiota and metabolite production, lysyl–valine and lysyl–proline levels were found to be positively correlated with Enterococcus and Lactobacillus abundance. However, Pediococcus was positively correlated with some metabolites contributing to nutritional status and immune function. According to our data, Pediococcus, Enterococcus, and Lactobacillus mainly participate in protein degradation, amino acid metabolism, and lactic acid production in fermented feed. Our results provide new insights into the dynamic changes in metabolism that occurred during the solid-state fermentation of corn–soybean meal feed using compound strains and should facilitate the optimization of fermentation production efficiency and feed quality. Full article