Chemical composition and dietary fibre of yellow and green commercial soybeans (Glycine max)

Alternative Method for Glyphosate Determination in Unroasted Green Coffee Beans by Liquid Chromatography Tandem Mass Spectrometry (LC-MS/MS)

This research proposes an alternative method to detect and quantify glyphosate residues in unroasted green coffee beans by LC-MS/MS. The sample preparation was conducted without derivatization steps, with integrated cleanup, which improves the analytical method's frequency. Validation results were consistent with the requirements of the regulatory guidelines employed. Specificity, linearity (r2 = 0.9991), precision (RSD ≤ 9%), and recovery (92-112%) were ensured, with a satisfactory limit of quantification (LOQ = 0.48 mg kg-1). These data demonstrate that the method is suitable for monitoring glyphosate residues in unroasted coffee beans while offering simplicity and speed in sample preparation. The method was applied to analyze authentic unroasted coffee bean samples, in which two of them were contaminated with glyphosate ( Collapse

Key Words

• Coffea arabica
• food safety
• herbicide
• method validation
• residue monitoring
• sample preparation

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MESH Headings

• Glyphosate
• Glycine/analogs & derivatives
• Glycine/analysis
• Tandem Mass Spectrometry/methods
• Coffea/chemistry
• Food Contamination/analysis
• Seeds/chemistry
• Herbicides/analysis
• Chromatography, High Pressure Liquid/methods
• Pesticide Residues/analysis
• Chromatography, Liquid/methods
• Coffee/chemistry
• Liquid Chromatography-Mass Spectrometry

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Grants

• Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
• Fundação de Amparo à Pesquisa do Estado de Minas Gerais
• Conselho Nacional de Desenvolvimento Científico e Tecnológico

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Affiliation(s)

Ana Carolina Pereira Paiva Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570900, Brasil
Emanuel Carvalho de Assis Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570900, Brasil
Leonardo d’Antonino Department of Soil, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570900, Brasil
Maria Eliana Lopes Ribeiro de Queiroz Department of Chemistry, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570900, Brasil
Antonio Alberto da Silva Department of Agronomy, Universidade Federal de Viçosa, Viçosa, Minas Gerais 36570900, Brasil

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Germplasm Resources and Metabolite Marker Screening of High-Flavonoid Tartary Buckwheat (Fagopyrum tataricum)

Tartary buckwheat is an annual minor cereal crop with a variety of secondary metabolites, endowing it with a high nutritional and medicinal value. Flavonoids constitute the primary compounds of Tartary buckwheat. Recently, metabolomics, as an adjunct breeding method, has been increasingly employed in crop research. This study explores the correlation between the total flavonoid content (TFC) and antioxidant capacity in 167 Tartary buckwheat varieties. Ten Tartary buckwheat varieties with significant differences in flavonoid content and antioxidant capacity were selected by cluster analysis. With the use of liquid chromatography-mass spectrometry, 58 flavonoid compounds were identified, namely, 42 flavonols, 10 flavanols, 3 flavanones, 1 isoflavone, 1 anthocyanidin, and 1 proanthocyanidin. Different samples were clearly separated by employing principal component analysis and partial least-squares discriminant analysis. Eight differential flavonoid compounds were further selected through volcano plots and variable importance in projection. Differential metabolites were highly correlated with TFC and antioxidant capacity. Finally, metabolic markers of kaempferol-3-O-hexoside, kaempferol-7-O-glucoside, and naringenin-O-hexoside were determined by the random forest model. The findings provide a basis for the selection and identification of Tartary buckwheat varieties with high flavonoid content and strong antioxidant activity.

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.

Effect of Pea Legumin-to-Vicilin Ratio on the Protein Emulsifying Properties: Explanation in Terms of Protein Molecular and Interfacial Properties

In isolates from different pea cultivars, the legumin-to-vicilin (L:V) ratio is known to vary from 66:33 to 10:90 (w/w). In this study, the effect of variations in the L:V ratio on the pea protein emulsifying properties (emulsion droplet size (d3,2) vs protein concentration (Cp)) at pH 7.0 was investigated using a purified pea legumin (PLFsol) and pea vicilin fraction (PVFsol). Despite a different Γmax,theo, the interfacial properties at the oil-water interface and the emulsifying properties were similar for PLFsol and PVFsol. Hence, the L:V ratio did not affect the pea protein emulsifying properties. Further, PLFsol and PVFsol were less efficient than whey protein isolate (WPIsol) in stabilizing the emulsion droplets against coalescence. This was explained by their larger radius and thus slower diffusion. For this reason, the difference in diffusion rate was added as a parameter to the surface coverage model. With this addition, the surface coverage model described the d3,2 versus Cp of the pea protein samples well.

Short-Term Soy Bread Intervention Leads to a Dose-Response Increase in Urinary Isoflavone Metabolites and Satiety in Chronic Pancreatitis

Patients with chronic pancreatitis (CP) are particularly vulnerable to nutrient malabsorption and undernutrition caused by the underlying pathology of their disease. Dietary intervention trials involving soy isoflavones in patients with CP are limited and isoflavone metabolites have not yet been reported. We hypothesized soy bread containing plant-based protein, dietary fiber, and isoflavones would be well-tolerated and restore gut functional capacity which would lead to isoflavone metabolites profiles like those of healthy populations. Participants (n = 9) received 1 week of soy bread in a dose-escalation design (1 to 3 slices/day) or a 4-week maximally tolerated dose (n = 1). Dietary adherence, satiety, and palatability were measured. Isoflavone metabolites from 24 h urine collections were quantified using high-performance liquid chromatography. A maximum dose of three slices (99 mg of isoflavones) of soy bread per day was achieved. Short-term exposure to soy bread showed a significant dose-response increase (p = 0.007) of total isoflavones and their metabolites in urine. With increasing slices of soy bread, dietary animal protein intake (p = 0.009) and perceived thirst (p < 0.001) significantly decreased with prolonged satiety (p < 0.001). In this study, adherence to short-term intervention with soy bread in CP patients was excellent. Soy isoflavones were reliably delivered. These findings provide the foundation for evaluating a well-characterized soy bread in supporting healthy nutrition and gut function in CP.

Comparative nutritional and antimicrobial analysis of Himalayan black and yellow soybean and their okara

BACKGROUND

Soybean is believed to have good nutraceutical potential which is important for human health. Yellow soybean (YS) is generally used for the production of soymilk and other products, while black soybean (BS) is less explored. During the production of soymilk, residue, called okara is generated which is reported to have a good amount of nutrient content. Studies are generally performed with YS while BS is less explored. The present work is a comparison of the nutraceutical potential of BS and YS and their okara, mainly in terms of proximate, minerals, antinutrients, and isoflavone content and bioactivity of all types of samples in terms of antioxidant and antimicrobial activity.

RESULTS

Compared to raw soybean, protein content decreased significantly in both types of okara. Phytochemicals like ascorbic acid, catechin, quercetin, and gallic acid were significantly (P < 0.05) high in BS residue in comparison to respective raw soybean. Among isoflavones, daidzin and genistin were found significantly varying among all the samples, and glycitin and glycitein were not present in YS.

CONCLUSION

The nutraceutical potential and antimicrobial activity were comparative for both the raw beans and their okara, while the phytochemical contents and antioxidant activity were higher in the case of BS and its okara. © 2022 Society of Chemical Industry.

Polyphenol content and antioxidant activity of phytoestrogen containing food and dietary supplements: DPPH free radical scavenging activity by HPLC

Soy, red clover, chaste tree, hop and flax have all been found to contain a wide range of phytoestrogenic compounds, and a large number of dietary supplements contain their extracts as principal ingredients. This study is aimed to evaluate the total polyphenolic content and antioxidant activity of phytoestrogen-containing food and formulated dietary supplements. The HPLC-DPPH method was applied for DPPH free radical scavenging activity testing of various phytoestrogen-containing samples. Polyphenol content and antioxidant activity in dietary supplements were higher than in functional food samples; multiple-botanical-source preparations showed higher polyphenol content and antioxidant activity than the mono-botanical counterparts. Furthermore, the correlation between polyphenol content and anti-oxidant activity was strongly statistically significant, so it might be concluded that antioxidant activity is proportional to the content of these secondary metabolites. The most striking batch-to-batch deviations were represented by one chaste berry-based product (RSD 41.3 %) and one red clover derived product (RSD 57.9 %). The results of this study contribute to a better understanding of the phenolic profile and antioxidant properties of phytoestrogen containing food and dietary supplements.

Faba Bean: An Untapped Source of Quality Plant Proteins and Bioactives

Faba beans are emerging as sustainable quality plant protein sources, with the potential to help meet the growing global demand for more nutritious and healthy foods. The faba bean, in addition to its high protein content and well-balanced amino acid profile, contains bioactive constituents with health-enhancing properties, including bioactive peptides, phenolic compounds, GABA, and L-DOPA. Faba bean peptides released after gastrointestinal digestion have shown antioxidant, antidiabetic, antihypertensive, cholesterol-lowering, and anti-inflammatory effects, indicating a strong potential for this legume crop to be used as a functional food to help face the increasing incidences of non-communicable diseases. This paper provides a comprehensive review of the current body of knowledge on the nutritional and biofunctional qualities of faba beans, with a particular focus on protein-derived bioactive peptides and how they are affected by food processing. It further covers the adverse health effects of faba beans associated with the presence of anti-nutrients and potential allergens, and it outlines research gaps and needs.

Development of Selection Indices for Improvement of Seed Yield and Lipid Composition in Bambara Groundnut (Vigna subterranea (L.) Verdc.)

The underutilised grain legume bambara groundnut (Vigna subterranea) has the potential to contribute significantly to nutritional security. However, the lack of commercial cultivars has hindered its wider adoption and utilisation as a food source. The development of competitive cultivars is impeded by (1) lack of systematic data describing variation in nutritional composition within the gene pool, and (2) a poor understanding of how concentrations of different nutritional components interact. In this study, we analysed seed lipid and protein concentration and lipid composition within a collection of 100 lines representing the global gene pool. Seed protein and lipid varied over twofold with a normal distribution, but no significant statistical correlation was detected between the two components. Seed lipid concentration (4.2–8.8 g/100 g) is primarily determined by the proportion of oleic acid (r² = 0.45). Yield and composition data for a subset of 40 lines were then used to test selection parameters for high yielding, high lipid breeding lines. From five selection indices tested using 15 scenarios, an index based on the seed number, seed weight, and oleic acid yielded a >50% expected increase in each of the mean values of seed number, pod dry weight, seed dry weight, and seed size, as well as an expected 7% increase in seed lipid concentration.

Outdoor cultivation of a novel isolate of the microalgae Scenedesmus sp. and the evaluation of its potential as a novel protein crop

A Danish strain of the green microalgae Scenedesmus sp. was isolated, identified and characterized with respect to productivity under outdoor cultivation conditions at northern latitudes. The algae were cultivated outdoors in Denmark in closed tubular photobioreactors using only sunlight, simple inorganic nutrients and under ambient temperatures. The biomass composition was evaluated in terms of protein content and quality. The average volumetric and areal biomass productivity obtained for the Scenedesmus sp. isolate during outdoor cultivation was 0.083 g dry matter L^-1 and 6.40 g dm m^-2  day^-1 , respectively. Thus, productivities are comparable to data reported in the literature under similar conditions. A strain-specific nitrogen to protein conversion factor of 5.5 was determined for the Scenedesmus sp. strain enabling more accurate protein estimations from simple nitrogen determination methods like Kjeldahl analysis in the future. The protein content was determined to be 52.4% of dried biomass for this Scenedesmus strain. The sum of essential amino acids was 42% which is high compared to other microalgae. The results are compared and discussed in comparison to other microalgae and soybean as a common plant protein source.

Metabolite Contents and Antioxidant Activities of Soybean (Glycine max (L.) Merrill) Seeds of Different Seed Coat Colors

Seed coat color is one of the main agronomical traits that determine the chemical quality of soybean seeds and has been used as a parameter during cultivar development. In this study, seeds of yellow (n = 10), greenish-yellow (n = 5), and light-yellow (n = 4) soybean accessions were evaluated for their contents of total protein, total oil, total phenolic (TPC), and five prominent fatty acids including palmitic acid (PA), stearic acid (SA), oleic acid (OA), linoleic acid (LA), and linolenic acid (LLA), relative to a control cultivar, and the effect of seed coat color on each was investigated. Antioxidant activity was also evaluated using 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity, Trolox equivalent antioxidant capacity (TEAC), and ferric reducing antioxidant power (FRAP). The results showed significant variations of metabolite contents and antioxidant activities between the soybeans. The average TPC, DPPH-radical scavenging activity, and FRAP were each in the order of greenish-yellow > yellow > light-yellow soybeans. In contrast, light-yellow soybeans contained a high level of OA and low levels of SA, LA, and LLA, each except LA differing significantly from yellow and greenish-yellow soybeans (p < 0.05). Our findings suggest that greenish-yellow and light-yellow soybeans could be good sources of antioxidants and high-quality soybean oil, respectively.

Physical, chemical and adsorption isotherm characteristics of fermented soybean cultivars, and cracked and dehulled African locust bean using selected Bacillus spp

Physical, chemical and adsorption isotherm characteristics of fermented soybean cultivars and dehulled African locust bean using selected Bacillus spp. were investigated. The CIE Lab, pH, titratable acidity, temperature and viable cells of the fermented cotyledons count increased significantly (p < 0.05) during the 5 days fermentation period. The CIE (Lab) varied with method of dehulling of cotyledons prior to and during fermentation, drying and milling. Protein content of African locust bean (25.50-40.25%) and soybean (40.15-50.60%) increased, but carbohydrate content reduced during fermentation of African locust bean (30.20-15.08%) and soybeans (18.21-12.08%). Adsorption isotherm patterns of the dried and milled African locust bean and soybean cultivars were sigmoidal. Of the eight models used, the BET and GAB models gave good fit, with a good correlation coefficient (0.95-0.76) and low average (81.93-14.82). The GAB had better fit, greater relevance and theoretical significance when compared with other models. Cracking to remove cotyledons from locust beans prior to fermentation yielded condiment with better aesthetic appeal and nutritional qualities than the traditional cooking for extensive period used for dehulling and softening of African locust bean seeds.

Study on the functional properties and structural characteristics of soybean soluble polysaccharides by mixed bacteria fermentation and microwave treatment

The soybean soluble polysaccharide was prepared by mixed fermentation of lactic acid bacteria and Neurospora crassa and microwave treatment. The functional properties and structure characteristics of soybean soluble polysaccharide before and after modification were compared. Results revealed that after fermentation treatment, the content of soybean soluble polysaccharide increased to 7.09%, which was 3.16 times that of raw materials, and the microwave treatment was further increased to 7.69%. The glucose adsorption capacity, glucose dialysis retardation index and the α-amylase activity inhibition ration of soybean soluble polysaccharides increased significantly, promotes intestinal flora growth in vitro after fermentation of mixed bacteria and microwave treatment. At the same time, the analysis of monosaccharide composition and structural characteristics showed that the monosaccharide components of soybean soluble polysaccharide were redistributed after modification treatment, Scanning electron microscopy showed that modified soybean soluble polysaccharide has a larger surface area; Fourier Transform Infrared spectroscopy and X-ray Diffraction proved that the modification has slight changes in the functional groups and crystal structure of soybean soluble polysaccharide. These results suggested that okara may be a potentially inexpensive source of natural soybean soluble polysaccharide and a potential functional food ingredient.

Using okara in diets for growing broilers

This study aimed to evaluate the effects of okara inclusion in diet for growing broilers on performance, carcass yield, blood and bone variables, quality and lipid oxidation of meat, and economic viability. For that, 575 Cobb 21-d-old male broilers were distributed in a completely randomized design with four levels of okara inclusion (25, 50, 75, and 100 g of okara kg−1diet) and a control group with five replicates and 23 birds each. There was no significant difference (P > 0.05) of okara levels on the performance variables, carcass yield, bone variables, and serum triglycerides, calcium and phosphorus at 42-d-old. Serum cholesterol levels showed a quadratic response (P < 0.05), in which the lowest value estimated was 65.3 g of okara kg−1of diet. Okara can be included in diets for broilers up to the level of 100 g kg−1without affecting the performance, carcass yield, bone variables, and lipid oxidation of meat. However, the best economic results were observed up to 50 g of okara kg−1of diet.

High angiotensin-I converting enzyme (ACE) inhibitory activity of Alcalase-digested green soybean (Glycine max) hydrolysates

As a protein-rich, underutilized crop, green soybean could be exploited to produce hydrolysates containing angiotensin-I converting enzyme (ACE) inhibitory peptides. Defatted green soybean was hydrolyzed using four different food-grade proteases (Alcalase, Papain, Flavourzyme and Bromelain) and their ACE inhibitory activities were evaluated. The Alcalase-generated green soybean hydrolysate showed the highest ACE inhibitory activity (IC50: 0.14 mg/mL at 6 h hydrolysis time) followed by Papain (IC50: 0.20 mg/mL at 5 h hydrolysis time), Bromelain (IC50: 0.36 mg/mL at 6 h hydrolysis time) and Flavourzyme (IC50: 1.14 mg/mL at 6 h hydrolysis time) hydrolysates. The Alcalase-generated hydrolysate was profiled based on its hydrophobicity and isoelectric point using reversed phase high performance liquid chromatography (RP-HPLC) and isoelectric point focusing (IEF) fractionators. The Alcalase-generated green soybean hydrolysate comprising of peptides EAQRLLF, PSLRSYLAE, PDRSIHGRQLAE, FITAFR and RGQVLS, revealed the highest ACE inhibitory activity of 94.19%, 99.31%, 92.92%, 101.51% and 90.40%, respectively, while their IC50 values were 878 μM, 532 μM, 1552 μM, 1342 μM and 993 μM, respectively. It can be concluded that Alcalase-digested green soybean hydrolysates could be exploited as a source of peptides to be incorporated into functional foods with antihypertensive activity.

Quantification of anti-nutritional factors and their correlations with protein and oil in soybeans

Soybeans contain about 30% carbohydrate, mainly consisting of non-starch polysaccharides (NSP) and oligosaccharides. NSP are not hydrolyzed in the gastrointestinal tract of monogastric animals. These NSP negatively affect the development of these animals, especially the soluble fraction. This work aimed to establish a method to quantify NSP in soybeans, using high performance liquid chromatography (HPLC), and to estimate correlations between NSP, oligosaccharides, protein and oil. Sucrose, raffinose + stachyose, soluble and insoluble NSP contents were determined by HPLC. Oil and protein contents were determined by near-infrared spectroscopy (NIRS). The soluble PNAs content showed no significant correlation with protein, oil, sucrose and raffinose + stachyose contents, but oligosaccharides showed a negative correlation with protein content. These findings open up the possibility of developing cultivars with low soluble NSP content, aiming to develop feed for monogastric animals.

Seed coat color and seed weight contribute differential responses of targeted metabolites in soybean seeds

The distribution and variation of targeted metabolites in soybean seeds are affected by genetic and environmental factors. In this study, we used 192 soybean germplasm accessions collected from two provinces of Korea to elucidate the effects of seed coat color and seeds dry weight on the metabolic variation and responses of targeted metabolites. The effects of seed coat color and seeds dry weight were present in sucrose, total oligosaccharides, total carbohydrates and all measured fatty acids. The targeted metabolites were clustered within three groups. These metabolites were not only differently related to seeds dry weight, but also responded differentially to seed coat color. The inter-relationship between the targeted metabolites was highly present in the result of correlation analysis. Overall, results revealed that the targeted metabolites were diverged in relation to seed coat color and seeds dry weight within locally collected soybean seed germplasm accessions.

Discrimination of transgenic soybean seeds by terahertz spectroscopy

Discrimination of genetically modified organisms is increasingly demanded by legislation and consumers worldwide. The feasibility of a non-destructive discrimination of glyphosate-resistant and conventional soybean seeds and their hybrid descendants was examined by terahertz time-domain spectroscopy system combined with chemometrics. Principal component analysis (PCA), least squares-support vector machines (LS-SVM) and PCA-back propagation neural network (PCA-BPNN) models with the first and second derivative and standard normal variate (SNV) transformation pre-treatments were applied to classify soybean seeds based on genotype. Results demonstrated clear differences among glyphosate-resistant, hybrid descendants and conventional non-transformed soybean seeds could easily be visualized with an excellent classification (accuracy was 88.33% in validation set) using the LS-SVM and the spectra with SNV pre-treatment. The results indicated that THz spectroscopy techniques together with chemometrics would be a promising technique to distinguish transgenic soybean seeds from non-transformed seeds with high efficiency and without any major sample preparation.

Nutritional quality and ions uptake to PTNDS in soybeans

Porous-tube nutrient delivery system (PTNDS) allows high control of the root environment and prevents plant infections in both microgravity and ground conditions. In this paper, six soybean cultivars ('ZH13', 'ZH57', 'LD10', 'HH35', 'HH43', and 'ZGDD') were evaluated in terms of yield, photosynthetic efficiency, insoluble dietary fiber and ions uptake efficiency. Besides proximal composition, the concentrations of mineral and isoflavones were monitored in the seeds. 'HH35' and 'ZH13' plants showed much higher yield and harvest index, in addition to the lower lignin content of inedible biomass. Data showed that 'HH35' had the higher photosynthetic efficiency of soybean leaves with regard to photosynthetic rate and instantaneous carboxylation efficiency, whereas chlorophyll ratio and carotenoids content were no difference with the other cultivars. Both cations and anions except NH4(+) and H2PO4(-), were accumulated excessively compared to controls, especially with anions in PTNDS.

Oligosaccharides composition in eight food legumes species as detected by high-resolution mass spectrometry

BACKGROUND

As probiotics, soy oligosaccharides have become popular as healthy foods to reduce disease risk. However, comprehensive information about oligosaccharides in different food legumes is limited.

RESULTS

In this study, eight oligosaccharides were well detected and quantified in different varieties of eight legume species using high-resolution mass spectrometry. It was determined that species could be distinguished by total content of oligosaccharides and their distribution modes. Among the studied species, Vigna unguiculata is a better resource of non-digestible oligosaccharides, while Vicia faba and black soybean (Glycine max) are at a disadvantage. Normally, stachyose predominates in non-digestible oligosaccharides, except in mung bean and broad bean, where verbascose predominates. For mung bean and green soybean, the seed coat should be taken into account for oligosaccharide consumption. The developed high-resolution mass spectrometry method greatly simplified the sample preparation process and permitted the identification of oligosaccharides without reference compounds.

CONCLUSION

This work involved extensive sample collecting and provided useful information for consumers. The developed method may be useful for rapid quantification of oligosaccharides in related foods.

Physicochemical and Functional Properties of Insoluble Dietary Fiber Isolated from Bambara Groundnut (Vigna subterranea [L.] Verdc.)

Bambara groundnut (BGN) is a widely cultivated legume with a rich nutritional profile, yet despite its many benefits it still remains underutilized. To highlight its potential value, 4 BGN varieties-brown, red, black eye, and brown eye were subjected to sequential enzymatic treatments followed by centrifugation to obtain the insoluble dietary fiber (IDF) fraction. The IDFs were vacuum-dried and evaluated for color, hydration properties, fat absorption, polyphenolic compounds, neutral sugars, and uronic acids. An optimized white bread formulation was also determined using brown BGN-IDF in an optimal (IV) mixture design. Three mixture components constrained at lower and upper limits (water: 57% to 60%, yeast: 2.3% to 5.3%, and BGN-IDF: 7% to 10%) were evaluated for their effects on responses of specific loaf volume, gumminess, chewiness, and resilience of the loaves. All BGN-IDFs differed significantly (P ≤ 0.05) across all color parameters. Polyphenols were significantly (P ≤ 0.05) highest in red and brown BGN-IDFs. Arabinose/galactose (31.04% to 37.12%), xylose (16.53% to 27.30%), and mannose (14.48% to 22.24%) were the major sugars identified. Swelling capacity was significantly (P ≤ 0.05) highest for brown eye BGN-IDF (7.72 ± 0.49 mL/g). Water retention capacity ranged from 1.63 to 2.01 g water/g dry weight. Fat absorption for red BGN-IDF differed significantly (P ≤ 0.05). Furthermore, the best optimal white bread formulation enriched with brown BGN-IDF was established with numerical optimization at 59.5% water, 4.3% yeast, and 8.5% BGN-IDF. Overall positive physicochemical and functional properties were observed for BGN-IDFs, and it was shown that an optimal white bread enriched with BGN-IDF could be produced.

Metabolite changes during natural and lactic acid bacteria fermentations in pastes of soybeans and soybean-maize blends

The effect of natural and lactic acid bacteria (LAB) fermentation processes on metabolite changes in pastes of soybeans and soybean-maize blends was studied. Pastes composed of 100% soybeans, 90% soybeans and 10% maize, and 75% soybeans and 25% maize were naturally fermented (NFP), and were fermented by lactic acid bacteria (LFP). LAB fermentation processes were facilitated through back-slopping using a traditional fermented gruel, thobwa as an inoculum. Naturally fermented pastes were designated 100S, 90S, and 75S, while LFP were designated 100SBS, 90SBS, and 75SBS. All samples, except 75SBS, showed highest increase in soluble protein content at 48 h and this was highest in 100S (49%) followed by 90SBS (15%), while increases in 100SBS, 90S, and 75S were about 12%. Significant (P < 0.05) increases in total amino acids throughout fermentation were attributed to cysteine in 100S and 90S; and methionine in 100S and 90SBS. A 3.2% increase in sum of total amino acids was observed in 75SBS at 72 h, while decreases up to 7.4% in 100SBS at 48 and 72 h, 6.8% in 100S at 48 h and 4.7% in 75S at 72 h were observed. Increases in free amino acids throughout fermentation were observed in glutamate (NFP and 75SBS), GABA and alanine (LFP). Lactic acid was 2.5- to 3.5-fold higher in LFP than in NFP, and other organic acids detected were acetate and succinate. Maltose levels were the highest among the reducing sugars and were two to four times higher in LFP than in NFP at the beginning of the fermentation, but at 72 h, only fructose levels were significantly (P < 0.05) higher in LFP than in NFP. Enzyme activities were higher in LFP at 0 h, but at 72 h, the enzyme activities were higher in NFP. Both fermentation processes improved nutritional quality through increased protein and amino acid solubility and degradation of phytic acid (85% in NFP and 49% in LFP by 72 h).

Novel development and characterisation of dietary fibre from yellow soybean hulls

Dietary fibres (DFs) from yellow soybean hulls (Glycine max) were developed by mimicking pH in the human digestive system. Using both traditional AOAC991.43 and newly developed AOAC2011.25 methods, DFs were quantified, and their physicochemical properties were characterised by determining colour, particle size, water absorption and solubility capacity. Viscoelastic properties of the fibres with whole wheat flours were evaluated using dynamic rheological measurements. The results showed that colour of lightness (L value) was significantly improved (p<0.05). The levels of soluble, insoluble, and total dietary fibres determined by 2011.25 were 2.6±0.7%, 85.9±0.4%, and 88.5±0.8% (as is), respectively. There was an approximately 50% increase of total dietary fibre in the treatment, which reached 98.6±0.8% (dry basis). The results clearly indicated that acid-base hydrolysis and autoclaving processes in yellow soybean hulls could significantly boost total dietary fibre content, which has potential application in snacks.

Seed maturity differentially mediates metabolic responses in black soybean

The soybean seed is placed in the middle of the morphological and developmental alterations, such as changes in seed size, weight, and colour, and alteration of the composition and contents of metabolites during maturation. In this study, we used black soybean seeds to investigate the effect of maturity on metabolite levels at different maturity stages. Seeds were sorted into five maturity categories, from M1 to M5, based on seed size and external pigmentation. Maturity stages M1, M3, and M5 are equivalent to R6, R7, and R8 on the soybean reproductive growth stage scale, indicating full seed, beginning maturity, and full maturity, respectively. As seed maturation progressed, the seed size decreased and the water soluble extract changed, indicating that a change of seed pigmentation occurred. At the same time, numerous metabolites responded differentially to seed maturation. The partial least squares (PLS) scores plot indicated that the metabolic alteration during maturation was clearly visible. Furthermore, isoflavones were highly associated with seed maturity on the PLS loading plot while fatty acids, glucose, fructose, and sucrose were less linked with seed maturity, indicating that those metabolites responded less to seed maturation. Overall, the results indicate that each category of metabolites is mediated differentially during maturation in black soybean seeds.

ACE-Inhibitory Peptide Isolated from Fermented Soybean Meal as Functional Food

Biologically active peptides as components in functional foods exhibit diverse activities and exert health effects in humans, just as the angiotensin I-converting enzyme (ACE)-inhibitory peptide exerts an antihypertensive effect. The solid-state fermentation of soybean meal was conducted using Bacillus subtilis natto at an appropriate temperature to accelerate proteolytic hydrolysis, and the crude extract containing ACE-inhibitory peptides was sequentially purified by ultrafiltration, gel chromatography and reverse phase-HPLC. A novel ACE-inhibitory peptide was obtained and its ACE-inhibitory activity was 84.1% with an IC50 value of 0.022 mg/ml. The results suggest that these ACE-inhibitory peptides obtained from the solid-state fermentation of soybean meal using B. subtilis natto have good potential for application in the management of hypertension and the fermented soybean meal has good potential for application in the production of a novel physiologically functional food.

Effect of fermentation and dynamic high pressure microfluidization on dietary fibre of soybean residue

Soybean residue is the main by-product of making soybean milk and tofu, and there is considerable interest in its recovery, recycling and upgrading. This work was to study the effect of fermentation with lactic acid bacteria and dynamic high pressure microfluidization (DHPM) on fibre fractions, fibre composition, surface topography and X-ray diffraction of dietary fibre in soybean residue. The results show that both fermentation and DHPM increased soluble dietary fibre (6.4-9.7 g/100 g and 6.4-14.0 g/100 g, respectively) and decreased the insoluble:soluble ratio (11.6-7.8 and 11.6-4.5, respectively). The minimum insoluble:soluble ratio (2.5) was obtained in samples with combined fermented and DHPM-treated at 200 MPa. The loss of hemicellulose was observed after fermentation and DHPM, while the cellulose content did not show significant differences. Microstructural and crystal structure analysis indicated that fermentation resulted in the modification of the fibrous structure with reduced crystallinity and DHPM damaged the structure to form rugged surface.

Physicochemical characteristics and functional properties of vitabosa (mucuna deeringiana) and soybean (glycine max)

Physicochemical characteristics and functional properties of vitabosa flour (Mucuna deeringiana) and soybean flour (Glycine max) were determined. Oil absorption capacity was higher in vitabosa. Water absorption capacity was higher in soy and it was affected by the change in the ionic strength of the medium. Emulsifying Activity (EA) decreased with increasing concentration of flour, while Emulsifying Stability (ES) showed an increased. EA and ES of flours have more ionic strength in the range between 0.0 and 0.4 M, but it is reduced afterwards with the higher concentration of NaCl. Foaming stability varied with the concentration of flour solution reaching maximum values of 39 and 33% for vitabosa and soybean, respectively at 10% flour concentration.Vitabosa had the best foaming capacity (56% to 0.6 M) compared with soybeans (47% to 0.4 M). Maximum capacity of gelation was observed in vitabosa at 10% flour concentration. Increases in ionic strength of the flour solution, at low salt concentrations (<0.4 M), improved the gelation of flours.

Hydroponic cultivation improves the nutritional quality of soybean and its products

Hydroponic cultivation allows the control of environmental conditions, saves irrigation water, increases productivity, and prevents plant infections. The use of this technique for large commodities such as soybean is not a relevant issue on fertile soils, but hydroponic soybean cultivation could provide proteins and oil in adverse environmental conditions. In this paper, the compositions of four cultivars of soybean seeds and their derivates, soy milk and okara, grown hydroponically were compared to that of the same cultivar obtained from soil cultivation in an open field. Besides proximal composition, the concentrations of phytic acid and isoflavones were monitored in the seeds, soy milk, and okara. Results demonstrated that, independent from the cultivar, hydroponic compared to soil cultivation promoted the accumulation of fats (from 17.37 to 21.94 g/100 g dry matter) and total dietary fiber (from 21.67 to 28.46 g/100 g dry matter) and reduced isoflavones concentration (from 17.04 to 7.66 mg/kg dry matter), whereas protein concentration was unaffected. The differences found in seed composition were confirmed in the respective okara products, but the effect of cultivation system was not significant looking at the soy milk composition. Data showed that hydroponic cultivation improved the nutritional quality of soybean seeds with regard to fats and dietary fiber. They also suggest that specific cultivars should be selected to obtain the desired nutritional features of the soybean raw material depending on its final destination.

Protective effects of polysaccharides from soybean meal against X-ray radiation induced damage in mouse spleen lymphocytes

The aim of this study was to investigate radioprotective effect of the polysaccharides from soybean meal (SMP) against X-ray radiation-induced damage in mouse spleen lymphocytes. MTT and comet assay were performed to evaluate SMP's ability to prevent cell death and DNA damage induced by radiation. The results show that, X-ray radiation (30 KV, 10 mA, 8 min (4 Gy)) can significantly increase cell death and DNA fragmentation of mouse spleen lymphocytes. Pretreatment with SMP for 2 h before radiation could increase cell viability, moreover, the SMP can reduce X-ray radiation-induced DNA damage. The percentage of tail DNA and the tail moment of the SMP groups were significantly lower than those of the radiation alone group (p < 0.05). These results suggest SMP may be a good candidate as a radioprotective agent.