Monitoring of carbon dioxide and equilibrium moisture content for early detection of physicochemical and morphological changes in soybeans stored in vertical silos

In the context of grain storage, impurities and soybeans defects in soybeans can significantly impact the equilibrium moisture content. This, cause moisture migration and heating of the stored product, leading to increased respiratory activity. Furthermore, temperature measurements within stored grain mass do not provide sufficient information for effective grain quality monitoring, primarily due to the grains excellent thermal insulating properties. To address this issue, we propose a different approach: monitoring the equilibrium moisture content and CO2 concentration as indicators of soybean respiration within the intergranular spaces of the stored grain mass. This study propose monitoring the CO2 concentration in the intergranular air along with environmental variables for early detection of physicochemical and morphological changes in soybeans stored in vertical silos using near infrared spectroscopy, X-ray diffraction and scanning electron microscopy. Thermogravimetry and spectrometry analyses revealed that the interrelationships among variables had a direct impact on soybean quality attributes. Specifically, the presence of soybeans with 5.2 % impurities led to an increased in respiration rates, resulting in a CO2 concentration of up to 5000 ppm and the consumption of up to 3.6 % of dry matter. Consequently, there were changes in the percentage of ash, proteins, fibers, and oils compositions. These findings highlight the potential for indirect assessments, enabling the prediction of physicochemical quality and contamination of soybeans stored in vertical silos through continuous monitoring of CO2 concentration and equilibrium moisture content.

Enhancing the functionality of plant-based Yogurt: Integration of lycopene through dual-stage fermentation of soymilk

Well-defined compositional assemblies of plant-based yogurt are of fast-growing awareness for world population concerning environmental sustainability, economic burdens and health risks. Soybean is an attractive candidate for plant yogurt, suffering from poor flavor, limited nutrition, and undesired allergens to offer healthy-functional segments. Herein, we deciphered a novel lycopene-soy yogurt by efficient two-stage fermentation of engineered B. subtilis and LAB. The fortified sogurt was ensured with redundant lycopene of 22.67 ± 2.95 mg/g DCW by engineered B. subtilis and enriched soy isoflavone from synergistic effects of engineered B. subtilis and LAB, possessing strong antioxidant capacity for upgrading functionality. Moreover, the desired pH, accelerated protein hydrolysis, enhanced amino acid availability, and expected sensory attributes cooperatively conferred lycopene-soy yogurt as healthy functional food. High potential is firstly ascribed to sequential dual culture of engineered B. subtilis and LAB in lycopene-soy yogurt, in which flavorful, hypoallergenic and antioxidative ingredients enabled functionalities for plant-based yogurt.

Film-forming properties and mechanisms of soy protein: Insights from β-conglycinin and glycinin

Extensive research has been conducted on soy protein films; however, limited information is available regarding the influence of the major components, β-conglycinin (7S) and glycinin (11S), on the film-forming properties of soy protein. This study aimed to isolate the 7S and 11S fractions in order to prepare films and investigate the impact of varying 7S/11S ratios on the film-forming solutions (FFS) and film properties. The findings revealed that higher 11S ratios led to increased protein aggregation, consequently elevating the storage modulus (G') of the FFS. Notably, an optimal 7S/11S ratio of 7S1:11S2 (CF3) significantly enhanced the film's water resistance. Specifically, it enhanced the water contact angle by an impressive 17.44 % and reduced the water vapor transmission rate by 27.56 %. These improvements were attributed to intermolecular interactions, involving hydrogen bonds and salt bridges, between the amino acid residues of 7S and 11S. As a result, a more uniform and dense microstructure was achieved. Interestingly, the mechanical and optical properties of the film were maintained by the different protein fractions examined. In summary, this study contributes to the understanding of the film-forming properties of soy protein, particularly the role of 7S and 11S.

Influence of pH and ionic strength on the physicochemical and structural properties of soybean β-conglycinin subunits in aqueous dispersions

Understanding the impact of pH and ionic strength on the physicochemical and structural properties of soy proteins at subunit level is essential for design and fabrication of many plant-based foods. In this study, soybean β-conglycinin and its subunit fractions αα' and β were dispersed in solutions with different pH values (3.7, 7.6, and 9.0) at low (5 mM NaCl) and high (400 mM NaCl) ionic strengths, respectively. The solubility, rheology, particle size, zeta potential, microstructure, secondary structure, and tertiary structure of the different dispersions were analyzed using a range of analytical methods. The β-conglycinin, αα'- and β-subunits aggregated near the isoelectric point (pH 3.7). Increasing the ionic strength led to the assembly of more homogeneous units. An increase in ionic strength at pH 7.6 and pH 9.0 led to electrostatic screening, which promoted dissociation of the aggregates. The β-subunit showed a greater sensitivity to pH and ionic strength than the αα'-subunits. Based on the evidence from a range of analytical methods, the highly hydrophilic extension region of the αα'-subunits played an important role in determining the stability of the β-conglycinin dispersions under different environmental conditions. Moreover, the N-linked glycans appeared to impact the conformation and aggregation state of the β-conglycinin.

Identification, Characterization, and Receptor Binding Mechanism of New Umami Peptides from Traditional Fermented Soybean Paste (Dajiang)

Dajiang, a traditional Chinese condiment, is made from fermented soybeans. It is highly popular among consumers as a result of its delicious umami flavor, which mainly originates from umami peptides. To examine the mechanism of umami taste in Dajiang, we selected Dajiang samples with strong umami taste and subjected them to purification and identification analysis using ethanol precipitation, gel chromatography, reversed-phase high-performance liquid chromatography, and ultraperformance liquid chromatography-tandem mass spectrometry. Subsequently, on the basis of toxicity and umami prediction analysis, we screened, synthesized, and characterized three novel bean umami peptides in Dajiang: TLGGPTTL, 758.4174 Da; GALEQILQ, 870.4811 Da; and HSISDLQ, 911.4713 Da. Their sensory threshold values were 0.25, 0.40, and 0.17 mmol/L, respectively. Furthermore, molecular docking results showed that hydrogen-bonding and hydrophobic interactions are important interaction forces in the binding of umami peptide to taste receptors. Ser147 and Glu148 of the T1R3 taste receptor are important amino acid residues for binding of the three umami peptides. This study uncovers the mechanism of umami-peptide-driven flavor in fermented soybean products.

Quantification of the environmental impact arising from the utilization of whole and defatted Okara in fermentative and dehydration processes

Okara is the insoluble pulp that remains after the grinding and filtration of soybeans during the production of soymilk and tofu. As it retains a noteworthy quantity of nutrients, there has been an increasing emphasis in the utilization of this residue for the development of sustainable processes. This study focused on assessing the environmental impact of employing okara as a medium for fermenting and dehydrating probiotic bacteria at laboratory scale. The evaluation was carried out using the Life Cycle Assessment (LCA) methodology, considering the entire process lifecycle. Whole okara and defatted okara were used as culture media for Lactiplantibacillus plantarum CIDCA 83114, followed by dehydration (either freeze-drying or spray-drying) and subsequent storage. For the purpose of comparison, both scenarios (whole and defatted okara) were evaluated using 1 kg of dehydrated final product for storage, as functional unit. Based on experimental results, the conservation of the received okara and the dehydration-storage (e.g., freezing and freeze-drying) phases were identified as the most significant environmental hotspots responsible for the most substantial impacts of the processes. The use of LCA facilitated the measurement of the environmental effects linked to the reutilization of okara as an agro-industrial residue, thus providing quantitative support when engineering its sustainable valorization.

Genome-wide association and RNA-seq analyses reveal a potential gene related to linolenic acid in soybean seeds

Linolenic acid (LA) has poor oxidative stability since it is a polyunsaturated fatty acid. Soybean oil has a high LA content and thus has poor oxidative stability. To identify candidate genes that affect the linolenic acid (LA) content in soybean seeds, a genome-wide association study (GWAS) was performed with 1,060 soybean cultivars collected in China between 2019-2021 and which LA content was measured using matrix-assisted laser desorption/ionization time-of-flight imaging mass spectrometry (MALDI-TOF IMS). A candidate gene, GmWRI14, encoding an APETALA2 (AP2)-type transcription factor, was detected by GWAS in cultivars from all three study years. Multiple sequence alignments showed that GmWRI14 belongs to the plant WRI1 family. The fatty acid contents of different soybean lines were evaluated in transgenic lines with a copy of GmWRI14, control lines without GmWRI14, and the gmwri14 mutant. MALDI-TOF IMS revealed that GmWRI14 transgenic soybeans had a lower LA content with a significant effect on seed size and shape, whereas gmwri14 mutants had a higher LA content. compared to control. The RNA-seq results showed that GmWRI14 suppresses GmFAD3s (GmFAD3B and GmFAD3C) and GmbZIP54 expression in soybean seeds, leading to decreased LA content. Based on the RNA-seq data, yeast one-hybrid (Y1H) and qRT-PCR were performed to confirm the transcriptional regulation of FAD3s by GmWRI14. Our results suggest that FAD3 is indirectly regulated by GmWRI14, representing a new molecular mechanism of fatty acid biosynthesis, in which GmWRI14 regulates LA content in soybean seeds.

Simultaneous detection of glycinin and β-conglycinin in processed soybean products by high-performance liquid chromatography-tandem mass spectrometry with stable isotope-labeled standard peptides

Glycinin and β-conglycinin are the two main allergic proteins in soybean. Due to their complex structures and lack of protein standards, it is difficult to achieve quantitative determination of these proteins in soybeans. In this study, an HPLC-MS/MS method was developed for the simultaneous determination of five subunits of glycinin (G1, G2, G3, G4, and G5) and three subunits of β-conglycinin (α, α', and β) in processed soybean products based on 8 specific peptides and their stable isotope-labeled peptides. Here, each specific peptide was derived from one of the above 8 subunits. When soy protein was extracted and digested with trypsin, 8 specific peptides, and corresponding stable isotope-labeled peptides were analyzed by HPLC-MS/MS. The linear range for the specific peptides was between 3.2 and 1000 ng/mL (R2 > 0.9955). The recoveries of added peptides ranged from 83.4% to 117.8%, and the intra-day precisions (% CV) were below 17.4%. The limit of quantification of each subunit of glycinin and β-conglycinin in processed soybean products (in terms of protein amount) was between 15.1 and 156.1 g/g. This method was successfully applied to the analysis of 8 subunits of glycinin and β-conglycinin in 68 different processed soybean products, which provides technical support for processed product quality evaluation and monitoring soybean processing technology.

Modulation of soy protein immunoreactivity by different matrix structures of lactic acid bacterium-induced soy protein gels: Epitope destruction during in vitro gastroduodenal digestion and absorption

Soy allergy is a common health problem. Food structure may change the gastroduodenal digestion and absorption of soy proteins, thus leading to the modulation of the immunoreactivity of soy proteins. In this study, lactic acid bacterium (LAB)-fermented soy protein isolates (FSPIs) were prepared at four concentrations (0.2 %-5.0 %, w/v) to present various matrix structures (nongel, NG; weak gel, WG; medium gel, MG; and firm gel, FG) and subjected to in vitro dynamic gastroduodenal digestion model. The results of sandwich enzyme-linked immunosorbent and human serum IgE binding capacity assays demonstrated that FSPI gels, especially the FSPI-MG/WG digestates obtained at the early and medium stages of duodenal digestion (D-5 and D-30), possessed greater potency in immunoreactivity reduction than FSPI-NG and reduced to 1.9 %-68.3 %. The transepithelial transport study revealed that the immunoreactivity of FSPI-MG/WG D-5 and D-30 digestates decreased through the stimulation of interferon-γ production and the induction of dominant Th1/Th2 differentiation. Peptidomics and bioinformatics analyses illustrated that compared with FSPI-NG, the FSPI-gel structure promoted the epitope degradation of the major allergens glycinin G2/G5, β-conglycinin α/β subunit, P34, lectin, trypsin inhibitor, and basic 7S globulin. Spatial structure analysis showed that FSPI-gel elicited an overall promotion in the degradation of allergen epitopes located in interior and exterior regions and was dominated by α-helix and β-sheet secondary structures, whereas FSPI-MG/WG promoted the degradation of epitopes located in the interior region of glycinin/β-conglycinin and exterior region of P34/basic 7S globulin. This study suggested that the FSPI-gel structure is a promising food matrix for decreasing the allergenic potential of allergenic epitopes during gastroduodenal digestion and provided basic information on the production of hypoallergenic soy products.

Production of marine bacterial metalloprotease A69 and evaluation of its potential in preparing soybean peptides with angiotensin-converting enzyme-inhibitory activity

BACKGROUND

Marine bacteria secrete a variety of proteases, which are a good source to explore proteases with application value. However, only a few marine bacterial proteases with a potential in bioactive peptides preparation have been reported.

RESULTS

The metalloprotease A69 from the marine bacterium Anoxybacillus caldiproteolyticus 1A02591 was successfully expressed in the food safe bacterium Bacillus subtilis as a secreted enzyme. A technique to efficiently produce protease A69 in a 15-L bioreactor was established, with a production of 8988 U mL-1 . Based on optimizing the hydrolysis parameters of A69 on soybean protein, a process for soybean protein peptides (SPs) preparation was set up, in which soybean protein was hydrolyzed by A69 at 4000 U g-1 and 60 °C for 3 h. The prepared SPs had a high content (> 90%) of peptides with a molecular mass less than 3000 Da and contained 18 amino acids. The prepared SPs showed high angiotensin-converting enzyme (ACE)-inhibitory activity, with an IC50 value of 0.135 mg mL-1 . Moreover, three ACE-inhibitory peptides, RPSYT, VLIVP and LAIPVNKP, were identified from the SPs using liquid chromatography-mass spectrometry analysis.

CONCLUSION

The marine bacterial metalloprotease A69 has a promising potential for preparing SPs with good nutritional and potential antihypertensive effects, laying a good foundation for its industrial production and application. © 2023 Society of Chemical Industry.

Microencapsulation of phenolic compounds extracted from soybean seed coats by spray-drying

This study aimed to characterize and microencapsulate soybean seed coats phenolic compounds by spray-drying, evaluating physicochemical properties and storage stability. Different extraction methodologies were used to obtain crude extract (SCE), ethyl acetate fraction, water fraction, and bound phenolic extract. Extraction yield, total phenolic and flavonoid contents, and antioxidant capacity were determined. HPLC-electrospray ionization source-MS/MS analysis was performed on SCE. Microencapsulation by spray-drying of SCE incorporating 10%, 20%, and 30% maltodextrin (MD) was carried out. Drying yield (DY), encapsulation efficiency (EE), moisture, morphology and particle size, dry, and aqueous storage stability were evaluated on the microcapsules. SCE had 7.79 g/100 g polyphenolic compounds (mainly isoflavones and phenolic acids) with antioxidant activity. Purification process by solvent partitioning allowed an increase of phenolic content and antioxidant activity. Microcapsules with 30% MD exhibited the highest DY, EE, and stability. Microencapsulated polyphenolic compounds from soybean seed coats can be used as functional ingredients in food products. PRACTICAL APPLICATION: Soybean seed coat is a usually discarded agro-industrial by-product, which presents antioxidant compounds of interest to human health. These compounds are prone to oxidation due to their chemical structure; therefore, microencapsulation is a viable and reproducible solution to overcome stability-related limitations. Microencapsulation of soybean seed coats polyphenols is an alternative which protects and extends the stability of phenolic compounds that could be potentially incorporated into food products as a natural additive with antioxidant properties.

Use of soybean as an alternative protein source for welfare-orientated production of American alligators (Alligator mississippiensis)

Soybean meal based diets have been suggested to cause gastrointestinal issues in certain species when used as a protein alternative. Using a randomized design, we tested 1,728 alligators in one of 13 communal pens offered one of two diets (seven pens (n = 928) of soybean-based protein diets and six pens (n = 800) of animal-based protein diets) to determine if soybeans would negatively affect the growth, hide quality, behavior and health, when compared with an otherwise identical diet using animal-based protein. Both feeds were nearly identical in composition for protein and fat percentages and identical for all minerals and elements. Crude protein was a minimum of 50%, crude fat a minimum of 12%, crude fiber a minimum of 4%, and phosphorous was maintained at 1%. From this information we estimated the One Welfare of using soy as a protein in commercial diets. Although there was a statistically significant decrease in belly width (p = 0.0009; harvested hide size) for alligators fed soybean-based protein diets, all other measured parameters of soybean vs. animal-based protein diets were comparable, suggesting this environmentally sustainable alternative protein source warrants consideration as a feed base. Weight was not significantly different suggesting either diet would yield similar volumes of meat. Total length was significantly affected by diet. Hide quality was not negatively impacted by protein type, with both diets producing high quality hides free of defects (assessed at the salted hide stage prior to tanning). Behaviors were not influenced by the feed type, with animals fed either diet using the pen structures the same. Further, feeding times were the same suggesting the soybean-based protein diet was equally easy to eat and palatable as the animal-based protein diet. Behavior and feeding suggested soy-based diets do not alter time budgets or activities. There were no differences in the frequency or severity of pathologies for animals fed either diet. Respiratory (lung and trachea as a proxy to measure dust inhalation), gastrointestinal (small intestine as a proxy to measure digestive disturbances), and renal (kidney as a proxy for excretory stress) histopathology demonstrated neither diet was causing overt problems. One Welfare conclusions were feeding a soybean-based protein diet did not cause production or welfare issues. Further, soybean protein-based diets may be an environmentally sustainable alternative to currently used animal-based diets. Research examining different soybean protein concentrations and sources is warranted.

Research Note: Evaluation of standardized ileal amino acid digestibility in feed ingredients for Pekin ducks

The digestibility of crude protein (CP) and amino acids (AA) in feedstuffs including corn, soybean meal (SBM), and corn distillers dried grains with solubles (DDGS) was investigated in White Pekin ducks. The test ingredients were the sole source of AA and CP. A nitrogen-free diet was also formulated for determining endogenous losses of AA and nitrogen. Birds were fed a standard starter diet for the first 15 d posthatch. On d 16, 96 ducklings (860 ± 50 g BW) were selected and allocated into 1 of 4 dietary treatments containing the test ingredients with 6 replicates per treatment in a randomized complete block design. All the crumbled assay diets were offered ad-libitum for 5 d and contained chromic oxide as an indigestible marker at 0.05%. On d 21, ducks were euthanized to collect the ileal digesta for digestibility analysis. Basal endogenous losses were abundant in glutamine, aspartic acid, leucine, proline, and serine, consecutively. For apparent ileal digestibility (AID), lysine and methionine were the highest (P < 0.05) in SBM, followed by corn and DDGS. For threonine, the highest values (P < 0.05) were similarly noted for SBM, followed by DDGS and corn; the values were 80.44, 69.88, and 64.89%, consecutively. Considering standardized ileal digestibility (SID), higher values (P < 0.05) for SBM were similarly noted for all the amino acids including lysine, methionine, and threonine; the values were 89.40, 93.58, and 86.50%, respectively. Conclusively, improved AA and CP digestibility was noted with SBM. Dietary protein source affected the extent of digestibility at the distal ileum; and the utilization of digestible amino acid coefficients during ducks' feed formulation is emphasized.

Improvement of the functional value of green soybean (edamame) using germination and tempe fermentation: A comparative metabolomics study

Green soybean, also known as edamame, is a legume with high nutritional and functional value. Despite its growing popularity and potential health benefits, the functionality of green soybean has not been thoroughly studied. Previous research on the functionality of green soybean has largely focused on a limited number of specific, well-studied, bioactive metabolites, without comprehensively investigating the metabolome of this legume. Additionally, very few studies have explored the improvement of the functional value of green soybean. This study aimed to investigate the metabolome profile of green soybean, identify bioactive metabolites, and to further explore the potential improvement of the identified bioactive metabolites using germination and tempe fermentation. A total of 80 metabolites were annotated from green soybean using GC-MS and HPLC-PDA-MS. Among them, 16 important bioactive metabolites were identified: soy isoflavones daidzin, glycitin, genistin, malonyl daidzin, malonyl genistin, malonyl glycitin, acetyl daidzin, acetyl genistin, acetyl glycitin, daidzein, glycitein, and genistein, as well as other metabolites including 3,4-dihydroxybenzoic acid, 3-hydroxyanthranillic acid, 3-hydroxy-3-methylglutaric acid (meglutol), and 4-aminobutyric acid (GABA). Germination and tempe fermentation techniques were employed to potentially improve the concentrations of these bioactive metabolites. While showing improvements in amino acid contents, germination process did not improve bioactive metabolites significantly. In contrast, tempe fermentation was found to significantly increase the concentrations of daidzein, genistein, glycitein, acetyl genistin, acetyl daidzin, 3-hydroxyanthranillic acid, and meglutol (>2-fold increase with p < 0.05) while also improving amino acid levels. This study highlights the potentials of germination and fermentation to improve the functionality of legumes, particularly green soybean.

The transcriptome sequencing analysis reveals immune mechanisms of soybean fermented powder on the loach (Misgurnus anguillicaudatus) in response to Lipopolysaccharide (LPS) infection

The loach (Misgurnus anguillicaudatus), a small commercial fish that is widely cultivated for its high-quality protein, vitamins, minerals, and essential amino acid, is a member of the genus Misgurnus and the family Cyprinidae. In this study, we gave the LPS-injected loach fermented soybean meal and used transcriptome sequencing to investigate the impact of the fermented soybean powder on the loach's immune system. 3384 up-regulated genes and 12116 down-regulated genes were found among the 15500 differentially expressed genes, according to the results. The differentially expressed genes were shown to be involved in cellular processes, metabolic processes, cellular anatomical entities, and binding, according to the Go functional annotation. Meanwhile, the KEGG enrichment analysis indicated that the soybean fermented powder treated groups showed significant differences in DNA replication, Nucleotide excision repair, Fanconi anemia pathway, and Base excision repair pathways, suggesting that these pathways are closely related to the enhancement of the immune function of loach by soybean fermented powder. The particular conclusions not exclusively can provide a new conception for the rational utilization of soybean fermented powder but also can provide theoretical guidance for the subsequent healthy breeding of loach.

Feed intake and milk yield and composition of lactating dairy goats in response to partial substitution of soybean meal for formaldehyde-treated sesame meal in the diet

This study was conducted to evaluate the effect of substitution of soybean meal (SBM) for formaldehyde-treated sesame meal (FTSM) on nutrient intake and digestibility, ruminal and blood parameters and milk production and composition in lactating Murciano-Granadina goats. Forty lactating goats were randomly assigned to one of the following four treatments: (1) diet with 16.5% CP, containing SBM (CON); (2) diet with 16.5% CP, containing untreated SM (USM); (3) diet with 16.5% CP, containing FTSM (FT); and (4) diet with 14.5% CP containing FTSM (LPFT). The results showed that nutrient intake was highest in the FT group (p < 0.001), while it was similar between the CON and LPFT groups, except for the intake of CP, which was higher in the CON group. The FT and LPFT had lower ruminal pH compared to CON and USM groups (p < 0.001), with goats in group FT having the highest volatile fatty acids (VFA) production (p < 0.001). The highest propionate concentration was observed in the LPFT treatment (p < 0.001), followed by the FT, CON, and USM treatments. Goats offered USM and LPFT treatments presented the highest and lowest acetate: propionate values, respectively, among the experimental groups (p < 0.001). The results also showed that LPFT goats had the lowest blood urea nitrogen (BUN) level (p = 0.004), while FT goats presented a lower non-esterified FA (NEFA) level compared with CON and LPFT goats (p = 0.01). Goats offered the FT diet had the highest milk yield (p = 0.002) and energy-corrected milk yield (p < 0.001) among all dietary groups. The highest milk fat (p < 0.001), protein (p = 0.001), lactose (p = 0.007), total solids (p = 0.003), and solids-not-fat (SNF) (p = 0.003) contents were observed in FT goats, which didn't differ from USM goats. The inclusion of formaldehyde-treated SM increased the percentage of C18:3 (p < 0.001) and C20:1 (p = 0.04) FAs compared with USM and CON treatments. Milk from USM, FT, and LPFT goats had lower levels of saturated (p < 0.001) and medium-chain FAs (p = 0.014) compared with CON goats, whereas milk from CON goats had lower levels of unsaturated, monounsaturated, and long-chain FAs compared to other groups (p < 0.001). The lowest and the highest concentrations of polyunsaturated FAs were observed in CON and LPFT goats, respectively (p = 0.001). It can be concluded that SBM can be advantageously replaced by formaldehyde-treated SM in the diet as a feasible alternative to improve feed intake and production performance of dairy goats.

Multi-dimensional analysis of heat-induced soybean protein hydrolysate gels subjected to ultrasound-assisted pH pretreatment

This study aimed to evaluate the gelation characteristics of soybean protein hydrolysate (SPH) extracted by enzyme-assisted aqueous extraction. Specifically, the changes in gelation behaviors for heat-induced (95 °C, 20 min) SPH dispersions treated with pH (pH 3, 5, 9; pH 7 as control) and ultrasound (U; 240 W, 30 min) were investigated. The results showed that typical gel behavior with high elastic nature in the viscoelasticity and network structures were observed during the heating process, where the disulfide bond played a dominant role in the gel network formation of all the samples. Notably, the heat-induced aggregation in the SPH gels was mainly formed by the association of the basic B polypeptide in 11S and β subunit in 7S. The most superior SPH gel was formed at pH 7 when assisted by ultrasonication during the heating process. This as-synthesized gel showed a uniform filamentous structure and exhibited the more excellent textural, rheological and thermal properties than those of the samples formed under acidic and alkaline conditions. These results are of great value in revealing the gelation mechanism of SPH.

[Distribution of vitamin K_2 content in Chinese traditional fermented soybean products]

OBJECTIVE

To determine the content of vitamin K_2 in different types of fermented bean products and analyze the difference of vitamin K_(2 )content.

METHODS

A total of 98 kinds of typical fermented bean products were included in Chinese traditional fermented bean products(Douchi, Sufu, soybean paste). Process, region, sales volume, raw materials and flavor were considered, and the content of vitamin K_2 in fermented bean products was determined by high performance liquid chromatography.

RESULTS

Chinese bean fermented foods generally contained vitamin K_2, and the subtype menaquinone-7(MK-7)was the main one. The content of vitamin K_2 in Douchi was the highest(437.55 μg/100 g), the content of vitamin K_2 in Sufu and Soybean paste were lower(7.48 μg/100 g and 2.47 μg/100 g). The content of vitamin K_2 in bacterial Douchi was higher than that in Mucor type and Aspergillus oryzae type which were 403.94, 232.98 and 81.00 μg/100 g(P<0.05). Soybean type Douchi was higher than that in black bean type of Douchi which were 610.41, 178.08 μg/100 g(P<0.05), and the content of vitamin K_2 in dry Douchi was higher than the content of vitamin K_2 in water Douchi which were 1 517.45 μg/100 g, 297.58 μg/100 g(P<0.05). However, there were no significant difference in the content of vitamin K_2 in Soybean paste and Sufu in different types and regions(P > 0.05).

CONCLUSION

Vitamin K_2 is widely contained in Chinese fermented bean products, and its content is mainly affected by fermentation microorganisms and processing technology.

Nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry metabolomics studies on non-organic soybeans versus organic soybeans (Glycine max), and their fermentation by Rhizopus oligosporus

BACKGROUND

Soybeans (Glycine max) are high in proteins and isoflavones, which offer many health benefits. It has been suggested that the fermentation process enhances the nutrients in the soybeans. Organic foods are perceived as better than non-organic foods in terms of health benefits, yet little is known about the difference in the phytochemical content that distinguishes the quality of organic soybeans from non-organic soybeans. This study investigated the chemical profiles of non-organic (G, T, U, UB) and organic (C, COF, A, R, B, Z) soybeans (G. max [L.] Merr.) and their metabolite changes after fermentation with Rhizopus oligosporus.

RESULTS

A clear separation was only observed between non-organic G and organic Z, which were then selected for further investigation in the fermentation of soybeans (GF and ZF). All four groups (G, Z, GF, ZF) were analyzed using nuclear magnetic resonance (NMR) spectroscopy along with liquid chromatography-tandem mass spectrometry (LC-MS/MS). In this way a total of 41 and 47 metabolites were identified respectively, with 12 in common. A clear variation (|log_1.5 FC| > 2 and P < 0.05) was observed between Z and ZF: most of the sugars and isoflavone glycosides were found only in Z, while more amino acids and organic acids were found in ZF. An additional four metabolites clustered as C-glycosylflavonoids were discovered from MS/MS-based molecular networking.

CONCLUSION

Chemical profiles of non-organic and organic soybeans exhibited no significant difference. However, the metabolite profile of the unfermented soybeans, which were higher in sugars, shifted to higher amino acid and organic acid content after fermentation, thereby potentially enhancing their nutritional value. © 2022 Society of Chemical Industry.

Identification of allergenic epitopes destroyed by two processing technologies of glycinin A2 from soybean

BACKGROUND

Glycinin is one of the most highly allergenic proteins in soybeans, and G2 is one of the five allergenic subunits of glycinin. Compared with the alkaline chain, the acidic chain A2 of the G2 subunit has strong allergenicity. However, the precise epitopes of A2 and the epitopes destroyed during processing are still unknown.

RESULTS

In the present study, preparation of two specific antibodies damaged by processing and phage display techniques were applied to locate the antigenic epitopes of glycinin A2 polypeptide chains disrupted by two processing techniques (thermal processing and ultra-high pressure combined thermal processing). Bioinformatics methods were used to predict the possible epitopes of the A2 chain. The A2 chain and its overlapping segments were introduced into T7 phages and expressed on phage shell by phage display. An indirect enzyme-linked immunosorbent assay was used to screen for antigenic epitopes that had been disrupted by the two processing technologies. The results showed that the dominant antigenic region disrupted by processing was located mainly in the A2-3-B fragment. The reacting experiment with the serum of allergic patients showed that the A2-3-B fragment protein was not only an antigenic region, but also an allergenic region. The two processing technologies destroyed the allergenic epitopes of A2 chain, thereby reducing the allergenicity of protein. The amino acids where the dominant allergenic region disrupted by processing was located were: ²³³ AIVTVKGGLRVTAPAMRKPQQEEDDDDEEEQPQCVE²⁶⁸ .

CONCLUSION

Precise epitopes of the acidic chain A2 in glycinin were identified and epitopes destroyed in two common processing methods were also obtained. The application products of rapid detection of de-allergenicity effect of processed food can be developed according to the location of processed destruction allergenic region, which is of great significance with respect to preventing the occurrence of soybean allergenic diseases. © 2022 Society of Chemical Industry.

Characterization of proteases from Irpex lacteus grown on minimally denatured soybean meal

BACKGROUND

Acid and thermal stabilities are important properties for the preparation of acidic protein beverage. It is an important method for enzymatic modification to improve the functional properties of protein. Irpex lacteus protease showed a selective hydrolysis to soy proteins. The purpose of this study was to investigate the mechanism of enzymatic hydrolysis and its effects on acid and thermal stabilities of soy proteins.

RESULTS

The I. lacteus protease selectively hydrolyzed the α and α' subunits of the native soybean β-conglycinin (7S globulin) to produce products that presented as the 55 kDa band upon sodium dodecyl sulfate polyacrylamide gel electrophoresis. The amino acid sequences of 55 kDa polypeptides were analyzed in gel multi-enzyme digestion followed by liquid chromatography-mass spectrometry. By matching the multi-enzyme digestion peptides with the published polypeptide chain sequences of the α and α' subunits, it was confirmed that the 55 kDa polypeptides were formed by eliminating amino acid residues on both sides of the N- and C-terminals. From the published protein structure database (https://www.uniprot.org/), it is known that the cleaved peptide bonds were in extension regions. Non-selective enzyme hydrolysis of both β-conglycinin (7S globulin) and glycinin (11S globulin), with corresponding drastic increases in the degree of hydrolysis, was observed when the substrates were preheated to the denaturation degree of 40% and above. However, 55 kDa hydrolyzed products and B polypeptides showed some extent of resistance to the proteolysis by I. lacteus protease even if denaturation degree was 100%. Both selective and non-selective hydrolysis of soy proteins by I. lacteus protease improved the acid and heat stabilities under the same hydrolysis conditions (enzyme/substrate ratio, time, and temperature).

CONCLUSION

Enzymatic hydrolysis of soybean proteins by the I. lacteus protease can effectively improve the acid and thermal stabilities of proteins. This discovery is significant to avoid aggregation during processing in the beverage industry. In the near future, the protease has potential application value for modification of other proteins. © 2022 Society of Chemical Industry.

Fermented Soybean Paste Attenuates Biogenic Amine-Induced Liver Damage in Obese Mice

Biogenic amines are cellular components produced by the decarboxylation of amino acids; however, excessive biogenic amine production causes adverse health problems. The relationship between hepatic damage and biogenic amine levels in nonalcoholic fatty liver disease (NAFLD) remains unclear. In this study, mice were fed a high-fat diet (HFD) for 10 weeks to induce obesity, presenting early-stage of NAFLD. We administered histamine (20 mg/kg) + tyramine (100 mg/kg) via oral gavage for 6 days to mice with HFD-induced early-stage NAFLD. The results showed that combined histamine and tyramine administration increased cleaved PARP-1 and IL-1β in the liver, as well as MAO-A, total MAO, CRP, and AST/ALT levels. In contrast, the survival rate decreased in HFD-induced NAFLD mice. Treatment with manufactured or traditional fermented soybean paste decreased biogenically elevated hepatic cleaved PARP-1 and IL-1β expression and blood plasma MAO-A, CRP, and AST/ALT levels in HFD-induced NAFLD mice. Additionally, the biogenic amine-induced reduction in survival rate was alleviated by fermented soybean paste in HFD-induced NAFLD mice. These results show that biogenic amine-induced liver damage can be exacerbated by obesity and may adversely affect life conservation. However, fermented soybean paste can reduce biogenic amine-induced liver damage in NAFLD mice. These results suggest a beneficial effect of fermented soybean paste on biogenic amine-induced liver damage and provide a new research perspective on the relationship between biogenic amines and obesity.

Genistein carbon dots exhibit antioxidant and anti-inflammatory effects in vitro

Genistein, an isoflavone from soybean, has attracted attention due to its health benefits, particularly antioxidant and anti-inflammatory activities. Clinical applications of genistein, however, have been limited due to the considerable hydrophobicity and lower bioavailability of the molecule. In this study, carbon dots (C-dots) synthesized from genistein as the carbonaceous precursor exhibit antioxidant properties in test-tube and cell experiments. Anti-inflammatory activity of the genistein-C-dots was also recorded in LPS stimulated macrophages, manifested in inhibition of pro-inflammatory cytokine levels and enhancement anti-inflammatory cytokine expression. The antioxidant and anti-inflammatory effects of the genistein-C-dots, particularly in comparison to the parent genistein molecules, likely account to the display of functional genistein residues on the C-dots' surfaces, and low band gap energy facilitating electron scavenging. Importantly, the genistein-C-dots featured biocompatibility and low cytotoxicity, underlining their potential as a therapeutic vehicle against inflammatory conditions.

Bile Acid Profile Influences Digestion Resistance and Antigenicity of Soybean 7S Protein

Soybean 7S storage protein (β-conglycinin) is the most important allergen, exhibits resistance in gastrointestinal (GI) digestion, and causes allergies in humans and animals. A previous study has demonstrated that 7S proteins contained innate amyloid aggregates, but the fate of these specific protein aggregates in intestinal digestion and correlation to allergenicity are unclear. In this study, via a modified INFOGEST static in vitro digestion and IgE binding test, we illustrate that the survived amyloid aggregates of soybean 7S protein in GI digestion might be dominant IgE epitopes of soybean protein in humans. The impact of conjugated primary bile acid salt (BS) profile on digestion resistance and immunogenicity of soybean protein is assessed, regarding the binding affinity of BS to protein aggregates with consideration of the BS composition and the physiologically relevant colloidal structure. The results show that chenodeoxycholate-containing colloidal structures exhibit high affinity and unfolding capacity to protein amyloid aggregates, promoting proteolysis by pancreatic enzymes and thus mitigating the antigenicity of soybean protein. This study presents a novel understanding of bile acid profile and colloidal structure influence on the digestibility and antigenicity of dietary proteins. It should be helpful to design in vitro digestion protocol and accurately replicate physiologically relevant digestion conditions.

The interaction of trehalose and molten globule state soybean 11S globulin and its impact on foaming capacities

BACKGROUND

Soybean 11S globulin has good functional properties, which are widely used in the field of food. However, natural soybean 11S globulin (N-11S) has low flexibility and is easy to aggregate, impacting its foaming process. Studies have shown that soybean 11S globulin in molten globule state (MG-11S) has better molecular flexibility than N-11S, and trehalose has been shown to improve the properties of proteins. Therefore, this study investigated the interaction mechanism between trehalose and MG-11S, and its impact on rheological and foaming properties of MG-11S.

RESULTS

The molecular docking and intrinsic fluorescence results showed that hydrogen bonding was the main interaction force at lower than 0.5 mol L^-1 trehalose added. Meanwhile, rheology and foaming showed that the MG-11S-trehalose complexes had better viscoelasticity, foaming ability (66.67-86.67%) and foaming stability (75.00-89.29%) than N-11S (16.67% foaming ability and 40.00% foaming stability); however, when the trehalose was higher than 0.5 mol L^-1 , molecular crowding occurred and H-bonds were weakened, resulting in reduction of foaming capacities. Microstructure determination showed that trehalose attached to the surface of foam membrane; meanwhile, the foaming structure of the complex with 0.5 mol L^-1 trehalose had a thicker liquid film with decreased drainage rate, less agglomeration and disproportionation of foam, illustrating the best foaming ability and foaming stability.

CONCLUSION

The results suggested that trehalose at different concentrations can interact with MG-11S through different mechanisms, and improve the foaming capacity of MS-11S. This provided a reference for the application of MS-11S in foaming food. © 2022 Society of Chemical Industry.

Effects of electron beam irradiation treatment on the structural and functional properties of okara insoluble dietary fiber

BACKGROUND

Insoluble dietary fiber (IDF) has beneficial physiological effects, such as the promoting of intestinal peristalsis, the improving of intestinal flora, and the absorbing of some harmful substances. Okara, a byproduct of soybean processing, is a potential source of IDF. But the larger particle size and poor water solubility of okara IDF have adverse effects on sensory properties and functional characteristics. Therefore, we used an emerging type of physical method is electron beam irradiation (EBI) to modify okara, and investigated that the effects of EBI doses on the structure and functional properties of okara IDF.

RESULTS

It was found that the electron beam treatment damaged the crystalline structure of IDF. Observation of the surface of EBI-treated IDF revealed a loose and porous morphology rather than the typical smooth structure. At a dose of 6 kGy, a smallest particle size and largest specific surface area of IDF was obtained, and these factors increased the apparent viscosity of an IDF dispersion. The water holding capacity, swelling capacity and the oil holding capacity upon irradiation at 6 kGy increased 74.13%, 84.76% and 41.62%, respectively. In addition, the capacity for adsorption of cholesterol, sodium cholate, glucose and nitrite ion were improved after electron beam treatment.

CONCLUSION

The modified okara IDF showed improved particle sizes and hydration properties, and these changes correlated with an improvement to the rough taste of IDF and improvements to the texture and storage period upon supplementation into food. © 2022 Society of Chemical Industry.

Analysis of Oligosaccharides in Korean Fermented Soybean Products by the Combination of Mass Spectrometry and Gas Chromatography

Doenjang (fermented soybean paste) and ganjang (soy sauce) are traditional fermented foods that are widely consumed in Korea. The oligosaccharides found in soybean and its fermented foods have great potential to improve the quality of foods; however, their structural details have not been well studied. In this study, we used advanced mass spectrometry and gas chromatography to analyze oligosaccharides and their monomeric composition in two fermented soybean products. In both foods, oligosaccharides with a degree of polymerization ranging from 3 to 7 were found. Their constituent monosaccharides were characterized; galactose, xylose, arabinose, and rhamnose were the predominant constituents of the oligosaccharides, and fucose, fructose, mannose, glucose, and N-acetylglucosamine were also found. The great structural diversity of the oligosaccharides found suggests that soybean carbohydrates are hydrolyzed and/or transformed during fermentation and may yield novel oligosaccharides.

Composition of proteins in fresh whey as waste in tofu processing

Tofu whey is a pale-yellowish liquid with specific aroma/taste which remains as the byproduct/waste after tofu squeezing and represents an environmental problem for direct disposal. Understanding the fresh tofu whey protein composition and the activity of bioactive peptides could be useful for the application of tofu whey as a functional food additive. Tofu whey was obtained during the tofu production from six soybean genotypes by hydrothermal processing in combination with chymosin-pepsin rennet. Basic 7S globulin (14.28-19.13%), γ-conglycinin (7.73-9.31%) and β-conglycinin (10.59-12.90%) were registered of the total extracted proteins. Glycinin was present with a dominant share of acidic (24.64-27.55%) versus basic polypeptides (12.18-14.61%) in the total extracted proteins. High content of total protein (22.67-28.00%), balanced content (9.76-13.33% of the total extracted proteins) and residual activity (1.95-3.76%) of trypsin inhibitors and low lectins content (5.04-5.48% of the total extracted proteins) indicate good nutritional value of the tofu whey samples. Tofu whey can be potentially useful for application as a cheap, nutritional and functional food additive and can enable sustainable production through the recycling of waste.

Standardized ileal digestibility of amino acids differs among sources of bakery meal when fed to growing pigs

A multistate experiment involving universities in IL, IN, KY, and MN was conducted as a part of the research efforts by the North-Central Coordinating Committee-42 on swine nutrition. The null hypothesis that there are no differences in the standardized ileal digestibility (SID) of amino acids (AA) among different sources of bakery meal was tested. Eleven sources of bakery meal were procured from swine-producing states in the United States and each source was included in one diet as the sole source of AA. A N-free diet was prepared as well. Diets were prepared in one batch and divided into four sub-batches that were subsequently distributed to the four participating universities. At each university, diets were fed to 12 pigs that had a T- cannula installed in the distal ileum. Pigs were allotted to incomplete Latin square designs with 12 pigs and 4, 5, or 6 periods for a total of 21 replicate pigs per diet. Each period lasted 7 d with ileal digesta being collected from the cannulas on days 6 and 7. Samples were analyzed for AA and the SID of each AA was calculated. Results indicated that there were differences (P < 0.001) in the SID of all AA except Pro among the 11 sources of bakery meal. The differences in SID of AA observed in this experiment were greater than what is usually observed among sources of the same ingredient, indicating that there is more variability among sources of bakery meal than among different sources of other ingredients. This is likely a consequence of different raw materials being used in the production of different sources of bakery meal. Regardless of source of bakery meal, the AA with the least SID was Lys indicating that some of the raw materials in the product streams used to generate the bakery meals may have been overheated. Additionally, the Lys:crude protein ratio in each source of bakery meal was not a good predictor of the SID of Lys, which likely reflects the different raw materials being included in the different meals. In conclusion, the SID of AA varies among different sources of bakery meal and the SID of Lys is less than the SID of all other indispensable AA.

Feeding dietary fermentable fiber improved fecal microbial composition and increased acetic acid production in a nursery pig model

The objective of this study was to determine the fermentable fiber (FF) content of several common fibrous ingredients fed to nursery pigs, and then evaluate the effect of dietary FF level on growth performance and fecal microbial composition. In experiment 1, 54 nursery pigs were randomly allotted to be fed nine diets with six replicate pigs per diet. Dietary treatments included a corn-soybean meal basal diet and eight test diets based on a mixture of the corn-soybean meal diet and corn distillers dried grains with solubles, sunflower meal, oat bran, wheat bran, corn bran, sugar beet pulp (SBP), apple pomace (AP) or soybean hulls (SH). In experiment 2, 180 nursery pigs were housed in 30 pens (six pigs per pen) and randomly allotted to be fed five diets with different FF to total dietary fiber (TDF) ratios, which were 0.52, 0.55, 0.58, 0.61, and 0.64, respectively. Results showed that the FF content in SBP, AP, and SH was greater (P < 0.01) than that in other ingredients. Water binding capacity of fibrous ingredients was positively correlated (P < 0.05) to the digestibility of TDF, acid detergent fiber, and non-starch polysaccharides in test ingredients. Pigs fed the SBP, AP and SH diets had greater (P < 0.05) fecal acetic acid and total short-chain fatty acids (SCFAs) concentrations compared with pigs fed other diets. Fecal acetic acid and total SCFAs concentrations were positively correlated (P < 0.05) with FF content in experimental diets. Average daily weight gain and average daily feed intake of pigs quadratically increased (P < 0.01) as the ratios of FF to TDF increased. Pigs in FF64% group showed higher (P < 0.05) ACE index and fecal acetic acid concentration compared with pigs fed the dietary FF/TDF ratio of 0.52 to 0.61. Compared with the classification system of soluble dietary fiber and insoluble dietary fiber, FF could better describe the mechanism by which dietary fiber has beneficial effects on pig gut health.

Determination and prediction of the available energy and amino acids digestibility of full-fat soybean fed to growing pigs

Two experiments were conducted to determine the digestible energy and metabolizable energy contents, as well as the apparent ileal digestibility and standardized ileal digestibility of amino acids in full-fat soybean fed to growing pigs. Ten full-fat soybean samples were collected from different areas in China and used in two experiments in this study. In Exp. 1, 66 growing pigs (initial body weight = 18.48 ± 1.2 kg) were randomly allotted to 1 of 11 diets (n = 6) including a corn basal diet and 10 experimental diets formulated by replacing the corn with 30% full-fat soybean. In Exp. 2, 11 growing pigs (initial body weight = 50.45 ± 3.2 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in a 6 × 11 Youden square design with 11 diets and 6 periods. The diets included an N-free diet based on cornstarch and sucrose and 10 experimental diets formulated with full-fat soybeans as the sole source of amino acids. Chromic oxide was added into the diets as an indigestible maker to calculate the digestibility of the amino acids. Results showed that there was considerable variation in neutral detergent fiber, acid detergent fiber, and trypsin inhibitor contents in the 10 full-fat soybean samples with a coefficient of variation greater than 10%. On a dry matter basis, the averaged digestible energy and metabolizable energy values in the 10 full-fat soybean samples were 4,855 and 4,555 kcal/kg, respectively, both were positively correlated with the ether extract content. The best-fitted prediction equations for digestible energy and metabolizable energy of full-fat soybean were: digestible energy, kcal/kg = 3,472 + 94.87 × ether extract - 97.63 × ash (R2 = 0.91); metabolizable energy, kcal/kg = 3,443 + 65.11 × ether extract - 36.84 × trypsin inhibitor (R2 = 0.91). In addition, all full-fat soybean samples showed high apparent ileal digestibility and standardized ileal digestibility values in amino acids and were all within the range of previously published values. Those values significantly varied among different samples (P < 0.05) for most amino acids, except for glycine and proline. In conclusion, full-fat soybean is a high-quality protein ingredient with high ileal digestibility of amino acids when fed to growing pigs, and the metabolizable energy value of full-fat soybean could be predicted based on its ether extract and trypsin inhibitor contents.

Standardized ileal digestibility of amino acids in extruded full-fat soybean fed to non-gestating, gestating, and lactating sows

This study was conducted to determine and compare the apparent ileal digestibility and standardized ileal digestibility (SID) of crude protein (CP) and amino acids (AA) in extruded full-fat soybean (EFSB) fed to nongestating, midgestating, late-gestating, and lactating sows. Six EFSB samples were collected from different sources. Fourteen nongestating sows (Landrace × Yorkshire; parity 3 to 5) were fitted with a T-cannula at the distal ileum. After recovery, sows were assigned to a replicated 7 × 3 incomplete Latin square design. The diets included a nitrogen-free (NF) diet and six experimental diets (EFSB 1 to 6). Eight midgestating sows (Landrace × Yorkshire; parity 3; day 48 of gestation), eight late-gestating sows (Landrace × Yorkshire; parity 3; day 90 of gestation), and eight lactating sows (Landrace × Yorkshire; parity 3; day 6 of lactation) were all assigned to four dietary treatments in a repeated 4 × 3 incomplete Latin square design. The diets included a NF diet and three experimental diets (EFSB 4 to 6). Results showed that there were significant differences in the AID and SID of CP and other AA in nongestating sows (P < 0.05), the AID and SID values of EFSB 1 to 3 were higher than those of EFSB 4 to 6, and the value of EFSB 5 was the lowest. For midgestating sows, there were differences in the AID of methionine (EFSB 5 had a lower value than EFSB 4 and 6) (P < 0.01). For late-gestating sows, only the AID of methionine (EFSB 5 had a lower value than EFSB 4 and 6), tryptophan (EFSB 5 had a higher value than EFSB 4 and 6), and proline (EFSB 5 had a higher value than EFSB 4) was different (P < 0.05), and the SID of methionine (EFSB 4 had a higher value than EFSB 5) and tryptophan (EFSB 5 had a higher value than EFSB 4 and 6) was different (P < 0.05). The SID of histidine and valine was greater in lactation than in nongestation (P = 0.045 and P = 0.02, respectively). The SID of isoleucine was greater in lactation than in nongestation and gestation (P < 0.01). The SID of methionine in nongestation was lower than in gestation and lactation (P < 0.01). The SID of cysteine was the lowest in midgestation (P = 0.045), and the SID of proline was greater in midgestation than in lactation and nongestation (P < 0.01). In conclusion, the AA ileal digestibility of six EFSB samples from different sources was different, and the ileal digestibility of CP and most AA was not affected by the physiological stage of sows.

Dietary glycine supplementation enhances the growth performance of hybrid striped bass (Morone saxatilis ♀× Morone chrysops ♂) fed soybean meal-based diets

This study was conducted to test the hypothesis that supplementing 1% and 2% glycine to soybean meal (SBM)-based diets can improve the growth performance of juvenile hybrid striped bass (HSB). The basal diets contained 15% fishmeal and 58% SBM (DM basis). Alanine was used as the isonitrogenous control in different diets. All diets contained 44% crude protein and 10% lipids (DM basis). There were four tanks (15 fish per tank) per dietary group, with the mean of the initial body weight (BW) of fish being 5.3 g. Fish were fed to apparent satiation twice daily, and their BW was recorded every 2 wk. The trial lasted for 8 wk. Results indicated that the BW, weight gain, protein efficiency ratio, and retention of dietary lipids in fish were enhanced (P < 0.05) by dietary supplementation with 1% or 2% glycine. In addition, dietary supplementation with glycine did not affect (P > 0.05) the feed intake of fish but increased (P < 0.05) the retention of dietary nitrogen, most amino acids, and phosphorus in the body, compared to the 0% glycine group. Dietary supplementation with 1% and 2% glycine dose-dependently augmented (P < 0.05) the villus height of the proximal intestine and reduced the submucosal thickness of the gut, while preventing submucosal and lamina propria hemorrhages. Compared with the 0% glycine group, dietary supplementation with 1% or 2% glycine decreased (P < 0.05) the proportion of skeletal-muscle fibers with diameters of 40 to 60 µm but increased (P < 0.05) the proportion of skeletal-muscle fibers with diameters of 80 to 100 µm and > 100 µm. Collectively, these findings indicate that glycine in SBM-based diets is inadequate for maximum growth of juvenile HSB and that dietary supplementation with 1% or 2% glycine is required to improve their weight gain and feed efficiency. Glycine is a conditionally essential amino acid for this fish.

Growing of fungi on the stored low denatured defatted soybean meals and the hydrolysis of proteins and isoflavone glycosides by fungal enzymes

Recently, more and more attention has been paid to the effects of fungal contamination and fungal enzymes secreted in raw grain on product quality. As the starting material of protein and active components, the quality of low denatured defatted soybean meals (LDSM) directly determines the qualities of subsequent products. In previous studies, we have revealed that infection with Aspergillus ochraceus protease causes significant hydrolysis of proteins. In this study, growing of fungi on the stored low denatured defatted soybean meals (LDSM) was analyzed by high-throughput sequencing and real-time PCR, which revealed that the abundance of Aspergillus increased significantly after storage. Twenty fungal proteases and 9 fungal glucosidases were found in stored LDSM and zymography showed that the proteases were of serine-type with some cysteine and aspartic activities. Proteolysis of the soybean storage proteins mainly occurred after the hydration of LDSM and the average molecular weight of soy proteins decreased from 57.9 kDa to 30.7 kDa after 60 min's of hydrolysis. Two-dimensional electrophoresis (2-DE) analysis found the polypeptide fragments from soybean 7S and 11S proteins with molecular weight around 10-25 kDa in the hydrated LDSM. Glycosylated isoflavones were hydrolyzed in both dry and hydrated stored LDSM which resulted in significant (p < 0.05) increase in the contents of isoflavone aglycones. This study suggested that fungi contamination be a new factor affecting the properties of LDSM derived soy protein products.

Dissipation and Dietary Risk Assessment of Pydiflumetofen Residues in Soybean

In this study, the quick, easy, cheap, effective, rugged, and safe (QuEChERS) method, combined with high-performance liquid chromatography−tandem mass spectrometry, was chosen for detecting pydiflumetofen residues in soybean plants, soybeans and soil, and assessing the risk of short- and long-term dietary intake. Pydiflumetofen concentrations ranging from 0.001−0.5 mg/L exhibited good linearity (r > 0.997). At varying doses, the average pydiflumetofen recovery rates and relative standard deviations among soybean plants, soybeans, and soil ranged from 83.9 ± 1.1% to 99.5 ± 3.3% and from 0.77 to 7.77%, respectively. The sensitivity, accuracy, and precision of the chosen methodology met the requirements of pesticide residue analysis. The results of the degradation dynamics test showed that the half-life of pydiflumetofen (t1/2) in soybean plants and in soil were 3.6 to 5.7 and from 7.9 to 25.7 d, respectively. Assessment of the concentration of pydiflumetofen residues in soybeans revealed acute and chronic dietary exposure risks of 0.06 and 7.54%, respectively. As these values are very low, pydiflumetofen residues in soybeans present an acceptable risk to public health. The results of this study will help to guide the practical application of pydiflumetofen and minimize the environmental risks associated with its use.

Autofluorescence-Based Investigation of Spatial Distribution of Phenolic Compounds in Soybeans Using Confocal Laser Microscopy and a High-Resolution Mass Spectrometric Approach

In this research, we present a detailed comparative analysis of the bioactive substances of soybean varieties k-11538 (Russia), k-11559 (Russia), k-569 (China), k-5367 (China), k-5373 (China), k-5586 (Sweden), and Primorskaya-86 (Russia) using an LSM 800 confocal laser microscope and an amaZon ion trap SL mass spectrometer. Laser microscopy made it possible to clarify in detail the spatial arrangement of the polyphenolic content of soybeans. Our results revealed that the phenolics of soybean are spatially located mainly in the seed coat and the outer layer of the cotyledon. High-performance liquid chromatography (HPLC) was used in combination with an amaZon SL BRUKER DALTONIKS ion trap (tandem mass spectrometry) to identify target analytes in soybean extracts. The results of initial studies revealed the presence of 63 compounds, and 45 of the target analytes were identified as polyphenolic compounds.

Comprehensive Metabolite Profiling of Four Different Beans Fermented by Aspergillus oryzae

Fermented bean products are used worldwide; most of the products are made using only a few kinds of beans. However, the metabolite changes and contents in the beans generally used during fermentation are unrevealed. Therefore, we selected four different beans (soybean, Glycine max, GM; wild soybean, Glycine soja, GS; common bean, Phaseolus vulgaris, PV; and hyacinth bean, Lablab purpureus, LP) that are the most widely consumed and fermented with Aspergillus oryzae. Then, metabolome and multivariate statistical analysis were performed to figure out metabolite changes during fermentation. In the four beans, carbohydrates were decreased, but amino acids and fatty acids were increased in the four beans as they fermented. The relative amounts of amino acids were relatively abundant in fermented PV and LP as compared to other beans. In contrast, isoflavone aglycones (e.g., daidzein, glycitein, and genistein) and DDMP-conjugated soyasaponins (e.g., soyasaponins βa and γg) were increased in GM and GS during fermentation. Notably, these metabolite changes were more significant in GS than GM. In addition, the increase of antioxidant activity in fermented GS was significant compared to other beans. We expect our research provides a basis to extend choice for bean fermentation for consumers and food producers.

The nutritive value of soybean meal from different sources for sows during mid- and late gestation

A precise understanding of the nutritive value of soybean meal (SBM) for pregnant sow is required for accurate feeding. Hence, we evaluated the nutritive value of 11 SBM samples from different sources for sows during mid and late gestation. In total, 24 mid-gestating sows (parity three; 230.3 ± 12.0 kg on day 37 of gestation) and 24 late-gestating sows (parity three; 238.8 ± 20.9 kg on day 72 of gestation) were assigned to a replicated 12 × 3 Youden square design with 12 diets and 3 periods. The 12 diets included a corn-based diet and 11 diets containing 25.50% SBMs from different sources. After 5-d adaptation, urine and feces were collected for 5 d. Although the chemical characteristics of SBM varied between samples, no differences were observed in digestible energy (DE), metabolizable energy (ME), apparent total tract digestibility (ATTD) of dry matter, gross energy, crude fiber, and neutral detergent fiber values in SBMs fed to both animal groups. However, de-hulled SBM 4 from Brazil displayed greater ATTD for nitrogen (N) in late-gestating sows (P < 0.05); animals displayed significantly (P < 0.01) greater ME, ME:DE ratio, and N net utilization values when compared with mid-gestating sows. The chemical composition of SBMs can be used to predict DE and ME values. In conclusion, ME, ME:DE ratio, and N net utilization SBM values for late-gestating sows were greater than in mid-gestating sows. Therefore, we should consider differences in ME values for SBMs when formulating diets for sows in mid and late gestation periods.

In Silico Approach of Glycinin and Conglycinin Chains of Soybean By-Product (Okara) Using Papain and Bromelain

This study explores utilization of a sustainable soybean by-product (okara) based on in silico approach. In silico approaches, as well as the BIOPEP database, PeptideRanker database, Peptide Calculator database (Pepcalc), ToxinPred database, and AllerTop database, were employed to evaluate the potential of glycinin and conglycinin derived peptides as a potential source of bioactive peptides. These major protein precursors have been found as protein in okara as a soybean by-product. Furthermore, primary structure, biological potential, and physicochemical, sensory, and allergenic characteristics of the theoretically released antioxidant peptides were predicted in this research. Glycinin and α subunits of β-conglycinin were selected as potential precursors of bioactive peptides based on in silico analysis. The most notable among these are antioxidant peptides. First, the potential of protein precursors for releasing bioactive peptides was evaluated by determining the frequency of occurrence of fragments with a given activity. Through the BIOPEP database analysis, there are several antioxidant bioactive peptides in glycinin and β and α subunits of β-conglycinin sequences. Then, an in silico proteolysis using selected enzymes (papain, bromelain) to obtain antioxidant peptides was investigated and then analyzed using PeptideRanker and Pepcalc. Allergenic analysis using the AllerTop revealed that all in silico proteolysis-derived antioxidant peptides are probably nonallergenic peptides. We also performed molecular docking against MPO (myeloperoxidases) for this peptide. Overall, the present study highlights that glycinin and β and α subunits of β-conglycinin could be promising precursors of bioactive peptides that have an antioxidant peptide for developing several applications.

Bacillus amyloliquefaciens CU33 fermented feather meal-soybean meal product improves the intestinal morphology to promote the growth performance of broilers

This study is aimed to select optimum keratin degradation ability from Bacillus strains for feather meal-soybean meal fermentation, and favorably water content for the strain during fermentation of feather meal-soybean meal, and finally investigate the effects of the fermented feather meal-soybean meal product (FFSMP) on growth performance, carcass trait, clinical blood biochemistry, and intestinal morphology of broilers. Thirty-six bacteria strains from soil, sewage pool, and feather waste were screened and selected Bacillus subtilis var. natto N21 (N21), B. subtilis CU14 (CU14), and B. amyloliquefaciens CU33 (CU33) with better keratinase activity and feather-degrading rate. The result of trial 1 showed that the FFSMP produced by CU33 had the optimum physiochemical characterizations, amino acid composition and feeding performance for broilers. Hence the effects of water content (45, 50, 55, and 60%) on FFMSP fermentation of CU33 were investigated in trial 2. Result showed that pH value, counts of Bacillus-like bacteria, γ-PGA, viscosity, surfactin yield and odor all significantly increased according to the water content (P < 0.05). The protease activity reached significantly highest in the 55% and 60% water content groups (P < 0.01). The broilers performance of 55% and 60% water content group were significantly higher than control group (P < 0.05) in weight gain (WG), feed intake (b) at 0 to 21-d-old and the WG, feed conversion ratio (FCR), and production efficiency factor at 0 to 35-d-old, and could reach the similar growth performance as fish meal group (P > 0.05). The fermentation groups significantly decreased urea nitrogen (P < 0.05) and increased creatinine (P < 0.05) in the blood. The fermentation groups also significantly decreased the crypt depth in the duodenum (P < 0.05) and increased villus height to crypt depth ratio of the duodenum (P < 0.05). In conclusion, CU33 shows the best degradation rate for feather and keratinase activity, and the FFSMP with a water content of 50% to 60% during fermentation is suggested. Diets supplemented with 5% FFSMP can promote the growth of broilers by improving the morphology of the duodenum and achieve the feeding effect of high-quality fish meal.

Isoflavone-enriched soybean leaves attenuate ovariectomy-induced osteoporosis in rats by anti-inflammatory activity

BACKGROUND

With an increasing aging population, postmenopausal osteoporosis has become a global public health problem. Previous evidence has shown that postmenopausal osteoporosis is a skeletal disease mainly caused by estrogen deficiency, generally accompanied by inflammation, and dietary isoflavones may ameliorate postmenopausal osteoporosis by anti-inflammatory activity. We have generated isoflavone-enriched soybean leaves (IESLs), but their anti-inflammatory activity and effect on attenuating osteoporosis are still obscure. Here, we determined the isoflavone profiles of IESLs and evaluated their anti-inflammatory activity in lipopolysaccharide-stimulated RAW 264.7 cells and anti-osteoporotic effects on ovariectomy-induced osteoporosis in rats.

RESULTS

IESLs had a high content of total isoflavone. Hydrolysate of IESLs (HIESLs) was rich with the aglycones daidzein and genistein, and HIESLs can significantly inhibit lipopolysaccharide-induced inflammation by reducing messenger RNA expression of iNOS, COX-2, IL6, and IL1β. Moreover, ovariectomized rats receiving aqueous extracts of IESLs (HIESLs) orally maintained more bone mass than control rats did, which was attributed to inhibition of osteoclastogenesis by downregulating the messenger RNA expression of the bone-specific genes RANKL/OPG, OC, and cathepsin K, and the inflammation-related genes IL6, NFκB, and COX-2.

CONCLUSION

IESLs may attenuate postmenopausal osteoporosis by suppressing osteoclastogenesis with anti-inflammatory activity and be a potential source of functional food ingredients for the prevention of osteoporosis. © 2020 Society of Chemical Industry.

Quantitative trait loci for seed isoflavone contents in 'MD96-5722' by 'Spencer' recombinant inbred lines of soybean

Isoflavones from soybeans [ Glycine max (L.) Merr.] have a significant impact on human health to reduce the risk of several major diseases. Breeding soybean for high isoflavone content in the seed is possible through marker-assisted selection (MAS) which can be based on quantitative trait loci (QTL). The objective of this study was to identify QTL controlling isoflavone content in a set of 'MD96-5722' by 'Spencer' recombinant inbred line (RIL) populations of soybean. Wide variations were found for seed concentrations of daidzein, glycitein, genistein, and total isoflavones among the RIL populations. Three QTL were identified on three different linkage groups (LG) represented by three different chromosomes (Chr). One QTL that controlled daidzein content was identified on LG A1 (Chr 5), and two QTL that underlay glycitein content were identified on LG K (Chr 9) and LG B2 (Chr 14). Identified QTL could be functional in developing soybean with preferable isoflavone concentrations in the seeds through MAS.

Comparative metabolomics in Glycine max and Glycine soja under salt stress to reveal the phenotypes of their offspring

Metabolomics is developing as an important functional genomics tool for understanding plant systems' response to genetic and environmental changes. Here, we characterized the metabolic changes of cultivated soybean C08 (Glycine max L. Merr) and wild soybean W05 (Glycine soja Sieb.et Zucc.) under salt stress using MS-based metabolomics, in order to reveal the phenotypes of their eight hybrid offspring (9H0086, 9H0124, 9H0391, 9H0736, 9H0380, 9H0400, 9H0434, and 9H0590). Total small molecule extracts of soybean seedling leaves were profiled by gas chromatography-mass spectrometry (GC-MS) and liquid chromatography-Fourier transform mass spectrometry (LC-FT/MS). We found that wild soybean contained higher amounts of disaccharides, sugar alcohols, and acetylated amino acids than cultivated soybean, but with lower amounts of monosaccharides, carboxylic acids, and unsaturated fatty acids. Further investigations demonstrated that the ability of soybean to tolerate salt was mainly based on synthesis of compatible solutes, induction of reactive oxygen species (ROS) scavengers, cell membrane modifications, and induction of plant hormones. On the basis of metabolic phenotype, the salt-tolerance abilities of 9H0086, 9H0124, 9H0391, 9H0736, 9H0380, 9H0400, 9H0434, and 9H0590 were discriminated. Our results demonstrated that MS-based metabolomics provides a fast and powerful approach to discriminate the salt-tolerance characteristics of soybeans.

Transgenic soybean plants overexpressing O-acetylserine sulfhydrylase accumulate enhanced levels of cysteine and Bowman-Birk protease inhibitor in seeds

Soybeans provide an excellent source of protein in animal feed. Soybean protein quality can be enhanced by increasing the concentration of sulfur-containing amino acids. Previous attempts to increase the concentration of sulfur-containing amino acids through the expression of heterologous proteins have met with limited success. Here, we report a successful strategy to increase the cysteine content of soybean seed through the overexpression of a key sulfur assimilatory enzyme. We have generated several transgenic soybean plants that overexpress a cytosolic isoform of O-acetylserine sulfhydrylase (OASS). These transgenic soybean plants exhibit a four- to tenfold increase in OASS activity when compared with non-transformed wild-type. The OASS activity in the transgenic soybeans was significantly higher at all the stages of seed development. Unlike the non-transformed soybean plants, there was no marked decrease in the OASS activity even at later stages of seed development. Overexpression of cytosolic OASS resulted in a 58-74% increase in protein-bound cysteine levels compared with non-transformed wild-type soybean seeds. A 22-32% increase in the free cysteine levels was also observed in transgenic soybeans overexpressing OASS. Furthermore, these transgenic soybean plants showed a marked increase in the accumulation of Bowman-Birk protease inhibitor, a cysteine-rich protein. The overall increase in soybean total cysteine content (both free and protein-bound) satisfies the recommended levels required for the optimal growth of monogastric animals.

[Prevention of osteoporosis by foods and dietary supplements. Soybean isoflavone and bone metabolism]

Soybean isoflavones show structural similarity to estradiol and therefore are known as phytoestrogen. Recently, isoflavones have received a great deal of attention for their preventive roles against hormone dependent diseases including postmenopausal osteoporosis, hyperlipidemia and cancer. Particularly, a number of studies have reported that soybean isoflavones inhibited bone loss in both female and male osteoporotic animal models as well as in postmenopausal women. On the other hand, since a kind of tablet with concentrated isoflavones has been recently applied for foods for specified health use (FOSHU), which are functional foods permitted to label a health claim by the Ministry of Health, Labor and Welfare in Japan, Food Safety Commission submitted a report the upper limit of daily isoflavone aglycon intake from FOSHU as well as from soybean products. This report demonstrates the effects of isoflavones on bone metabolism and safety.