Isoflavone composition, phenol content, and antioxidant activity of soybean seeds from India and Bulgaria

A review of conventional and rapid analytical techniques coupled with multivariate analysis for origin traceability of soybean

Soybean has developed a reputation as a superfood due to its nutrient profile, health benefits, and versatility. Since 1960, its demand has increased dramatically, going from a mere 17 MMT to almost 358 MMT in the production year 2021/22. These extremely high production rates have led to lower-than-expected product quality, adulteration, illegal trade, deforestation, and other concerns. This necessitates the development of an effective technology to confirm soybean's provenance. This is the first review that investigates current analytical techniques coupled with multivariate analysis for origin traceability of soybeans. The fundamentals of several analytical techniques are presented, assessed, compared, and discussed in terms of their operating specifics, advantages, and shortcomings. Additionally, significance of multivariate analysis in analyzing complex data has also been discussed.

Geographic distributions and the regionalization of soybean seed compositions across China

As one of major food crops, soybean is grown over a broad ecological region in China with considerable variations in environmental conditions, and the seed compositions of soybeans are diverse among different regions. To clarify the spatial patterns of soybean seed compositions, crude oil, protein, and 11 categories of functional components were quantified in 1792 soybean samples collected from a vast range of soybean planting regions across China spanning from 2010 to 2017. The Kriging interpolation maps presented a clear north-to-south (high latitude to low latitude) increasing trend in contents of crude protein and dietary fiber and decreasing trend in contents of crude oil, phospholipids, saponins, and carotenoids. Soybeans with high-level of total oligosaccharide were concentrated in the central region. Based on the geographical distribution of soybean nutritional components, weather conditions, and cultivation systems, the soybean production areas in China were divided into three regions and 10 subregions. This study highlights the geographic distribution of soybean nutritional compositions and provides scientific evidence for guiding the construction of high-quality edible soybean production bases in China.

Comparative investigation on variations of nutritional components in whole seeds and seed coats of Korean black soybeans for different crop years and screening of their antioxidant and anti-aging properties

This research was conducted to demonstrate the comparisons of nutritional constituents (isoflavone; anthocyanin; protein; fatty acid; oil) and biological properties (antioxidant, anti-aging) in whole seeds and seed coats of black soybeans for crop years. Isoflavones and anthocyanins showed considerable differences in cultivars and growth years with the ranges of 794.9-4195.3 μg/g and 2.3-14.4 mg/g, while other components exhibited slight variations. In particular, malonylgenistin and cyanidin-3-O-glucoside were observed the most abundant phenolics, comprising approximately 35.5 (778.0 μg/g) and 76.7% (4.6 mg/g) of total average contents (isoflavone: 2197.8 μg/g; anthocyanin: 6.0 mg/g). Moreover, the whole seeds and seed coats displayed excellent activities in antioxidant (radical; DNA protectant), tyrosinase inhibition, and elastase inhibition. Their effects significantly occurred with dose-dependent patterns as follows: elastase (150 μg/mL) > tyrosinase (600 μg/mL) > ABTS (1500 μg/mL) > DPPH (1500 μg/mL) with higher abilities of seed coats than whole seeds. The DNA protection exhibited higher rates in seed coats with > 90% at 200 μg/mL. Natably, Socheong (isoflavone; 4182.4 μg/g) and Geomjeong 2 (anthocyanin: 10.3 mg/g) cultivars may be recommended as potential sources to the development of functional agents and new cultivars owing to their high average phenolic contents.

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.

Origin and seed coat color differently affect the concentrations of metabolites and antioxidant activities in soybean (Glycine max (L.) Merrill) seeds

In this study, 54 soybean germplasms of different seed coat colors originated from America, China, Japan, and Korea were cultivated in Korea and analyzed for the contents of total oil, total protein, total phenolic, five fatty acids, and five isoflavones, and antioxidant activities using three assays. The soybeans showed significant variations (p < 0.05) of metabolite contents and antioxidant activities. Origin and seed coat color exhibited a slight or insignificant effect on total protein and total oil contents. In contrast, origin and seed coat color significantly affected the concentration of individual and total isoflavones, and total phenolics, with few exceptions. Whereas fatty acids were significantly affected by origin, seed coat color provided better information regarding the variations in antioxidant capacities. Together, multivariate and correlation analyses revealed important associations between biosynthetically-related metabolites. In general, origin and seed coat color differently influenced the concentration of different classes of metabolites and antioxidant activities.

Comparative Study of Natural Antioxidants from Glycine max, Anethum graveolensand Pimpinella anisum Seed and Sprout Extracts Obtained by Ultrasound-Assisted Extraction

The study aimed to evaluate the antioxidant potential of sprout and seed extracts from three species of plants, namely Glycine max (GMsp-sprouts, GMsd-seeds), Anethum graveolens (AGsp-sprouts, AGsd-seeds) and Pimpinella anisum (PAsp-sprouts, PAsd-seeds), which are widely accepted by consumers and have various applications in food flavoring, and also in natural medical treatments in the pharmaceutical industries. These plants are rich in valuable compounds that show a remarkable antioxidant power and are associated with many health benefits. Ethanol extracts were obtained by ultrasound-assisted extraction and they were comparatively evaluated for their in vitro antioxidant properties. The extracts were characterized by HPTLC, HPLC-DAD, total phenol content (TPC), total flavonoid content (TFC) analysis and antioxidant activities with different assays, such as total antioxidant capacity (TAC), 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assay (ABTS), 1,1-diphenyl 1-2-picryl-hydrazyl (DPPH) and iron binding ability of chelators. Our results showed that the sprout and seed extracts of the studied plants exhibited a high content of phytochemicals and promising antioxidant properties. The highest polyphenols content was detected for AGsd (53.02 ± 0.57 mg/g DW), PAsd (48.75 ± 0.34 mg/g DW) and the highest flavonoids content for PAsp (26.84 ± 0.57 mg/g DW). Moreover, the presence of valuable compounds was demonstrated by using HPTLC, FT-IR and HPLC-DAD techniques. In order to have a better understanding of the relationship between the biological properties and the electronic structure, a molecular modelling study of genistein was also conducted. Our approach to the comparative assessment of these three plant species was based on a priori knowledge from literature data; however, this study demonstrated that these plant extracts of seeds and also sprouts are excellent sources of natural antioxidants. Significant additional differences that were found in the phytochemical composition could be exploited in future research for pharmaceutical purposes.

Powerful Antioxidants and Cytotoxic Activities of the Methanol Extracts from Eight Soybean Cultivars

In the present study, the chemical composition and total phenolic (TPC) and total flavonoid contents (TFC) of eight soybean cultivars (Giza 21, Giza 22, Giza 35, Giza 111, Giza 82, Giza 83, Crawford, and Holliday) were estimated. Moreover, antioxidant activity and in vitro cytotoxic activities against HepG-2 and MCF-7 were evaluated. Giza 21, Giza 111, and Crawford cultivars recorded higher than 40% crude protein. The analysis revealed that TPC values in seed extracts ranged from 10.5 mg GAE/g extract in Giza 35 to 6.4 mg GAE/g extract in Giza 22. TFC varied from 1.20 mg QE/g extract in Giza 111 to 0.55 mg QE/g extract in Crawford. Giza 35 exhibited the highest content of genistein and daidzein and the highest free radical scavenging activity (61.833%). The results of the MTT assay demonstrated that the soybean methanolic extracts inhibited the proliferation of HepG-2 and MCF-7 cells in a dose-dependent manner. Giza 35 exhibited the highest cytotoxic activity. In conclusion, Giza 35 cultivar recorded the highest TPC and TFC values and antioxidant and cytotoxic activities. Therefore, this cultivar can be used as a source for the production of pharmaceutical and medicinal products rather than as a nutritional source of protein.

Metabonomics analysis of flavonoids in seeds and sprouts of two Chinese soybean cultivars

A popular food in China, soybean seeds and sprouts contained many biologically active substances which are beneficial to the human body, such as flavonoids. Northeast of China is the main producing area of soybean. The experimental materials came from the main soybean producing areas in Northeast China, this study compared flavonoids of two China cultivars of soybeans, Heinong52(HN52) and Heinong71(HN71). Here, we also considered the effects of germination on the chemical profile of flavonoids. Using a LC-ESI-MS/MS system, 114 differential flavonoid metabolites were identified. A total of 18 metabolites were significantly different between the two soybean varieties before germination, of which 14 were up-regulated and 4 were down-regulated. After germination, 33 significantly different metabolites were found in the two soybean sprouts, of which 19 were up-regulated and 14 were down-regulated. These experimental results revealed significant up-regulation of metabolites in soybean sprouts compared with soybean seeds, thus suggesting that soybean germination may increase content of flavonoid metabolites. There are six main pathways for the synthesis of flavonoids: isoflavonoid biosynthesis, flavonoid biosynthesis, flavone and flavonol biosynthesis, biosynthesis of secondary metabolites, and biosynthesis of phenylpropanoids. Soybean seeds lack flavone and flavanol biosynthesis and develop the capacity for this biosynthetic pathway after germination as sprouts. Isoflavonoid biosynthesis is the most abundantly utilized pathway.

Ultrasonic-assisted extraction of bioactive chlorogenic acid from heilong48 soybean variety: Parametric optimization and evaluation of physicochemical and bioactive properties

Chlorogenic acid (CA), especially that found in soybeans, is a rich bioactive compound but has received very little attention in research settings in past decades. Ultrasonic‐assisted extraction (UAE) could be an efficient method to increase CA release from soybeans. Hence, this study aimed to optimize UAE parameters for CA extraction from heilong48 soybean (HS) variety and evaluate the physicochemical and bioactive properties of the soybean. Optimization of ultrasound parameters with a Box–Behnken design found a frequency of 20.0 kHz, a power density of 30.0 W/L), a temperature of 37.9°C, and a time of 28.0 min to be the best conditions, which gave a CA yield of 5.007 ± 0.033 mg/g and 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical scavenging activity of 93.197 ± 0.213 μmol of AA eq/g dry sample; these were higher than those of a non–ultrasound‐treated (raw) HS sample (CA yield of 1.627 ± 0.528 mg/g and DPPH radical scavenging activity of 10.760 ± 0.207 μmol of AA eq/g dry sample). A satisfactory model was obtained. Scanning electron microscopy results confirmed the structural changes of the HS variety caused by the optimized UAE parameters. High total polyphenol contents (TPCs; 4.726 ± 0.002 mg GAE/g) and total phenolic acids (1.883 ± 0.005 mg GAE/g) and low total flavonoid contents (0.040 ± 0.008 mg RE/g) were obtained. A positive linear correlation between antioxidant activity and TPC was established. A protein–phenolic interaction in the HS variety was observed. The results established that polyphenols should be considered a significant component of the HS variety. Likewise, the HS variety could be used for CA extraction.

Single-frequency ultrasonic extraction of bioactive chlorogenic acid from heilong48 soybean variety: Parametric optimization and comprehensive evaluation of physicochemical and bioactive properties

Chlorogenic acid (CA), especially that found in soybean, is a rich bioactive compound but has received very little attention in research settings in past decades. Ultrasonic-assisted extraction (UAE) could be an efficient method to increase CA release from soybean. Hence, this study aimed to optimize UAE parameters for CA extraction from heilong48 soybean (HS) variety with comprehensive physicochemical and bioactive properties evaluation. Optimization of ultrasound parameters with Box-Behnken design (BBD) found frequency (20.0 kHz), power density (30.0 W/L), temperature (37.9℃), and time (28.0 min) as the significant optimized parameters, which gave CA yield of 5.007 ± 0.033 mg/g and DPPH of 93.197 ± 0.213 μmol AA eq/g dry sample and were higher than that of nonultrasound-treated (raw) HS sample (CA yield, 1.627 ± 0.528 mg/g, and DPPH, 10.760 ± 0.207 μmol AA eq/g dry sample). A satisfactory model was obtained. SEM results confirmed the structural alterations of HS variety caused by the optimized UAE parameters. High TPC (4.726 ± 0.002 mg GAE/g), TPA (1.883 ± 0.005 mg GAE/g), and low TFC (0.040 ± 0.008 mg RE/g) were obtained. A positive linear correlation between antioxidant activity and TPC was established. Protein-phenolic interaction in HS variety was observed. The results proposed that polyphenols should be considered as a significant component of HS variety. Likewise, HS variety could be utilized for CA extraction.

Isoflavone Changes in Immature and Mature Soybeans by Thermal Processing

The isoflavone changes occurring in mature soybeans during food processing have been well studied, but less information is available on the changes in immature soybeans during thermal processing. This study aimed to determine the effect of thermal processing by dry- or wet-heating on the changes in the isoflavone profiles of immature and mature soybeans. In the malonylglycoside forms of isoflavone, their deglycosylation was more severe after wet-heating than after dry-heating regardless of the soybean maturity. The malonyl forms of isoflavones in the immature seeds were drastically degraded after a short wet-heating process. In the acetylglycoside forms of isoflavone, dry-heating produced relatively low amounts of the acetyl types in the immature soybeans compared with those in the mature soybeans. These results were explained by the content of acetyldaidzin being relatively less changed after dry-heating immature soybeans but increasing four to five times in the mature soybeans. More of the other types of acetylglycoside were produced by dry-heating soybeans regardless of their maturity. Acetylgenistin in wet-heating was a key molecule because its content was unchanged in the immature soybeans during processing but increased in the mature soybeans. This determined the total acetylglycoside content after wet-heating. In contrast, most of the acetyl forms of isoflavone were produced after 90 to 120 min of dry-heating regardless of the seed maturity. It can be suggested that the pattern of isoflavone conversion was significantly affected by the innate water content of the seeds, with a lower water content in the mature soybeans leading to the greater production of acetyl isoflavones regardless of the processing method even if only applied for a relatively short time. The results suggested that the isoflavone conversion in the immature soybeans mainly follows the wet-heating process and can be promoted in the application of stronger processing.

Valorization of Glycine max (Soybean) Seed Waste: Optimization of the Microwave-Assisted Extraction (MAE) and Characterization of Polyphenols from Soybean Meal Using Response Surface Methodology (RSM)

The present study aimed at determining the optimal conditions for extraction of total phenolic compounds from soybean (Glycine max) meal, a by-product of the soybean seeds industry, using a green protocol with microwave-assisted extraction (MAE). A face-centered composite design (FCCD) was used for optimization. Based on a screening aimed to determine the factors that significantly influenced the responses, a 50% hydro-ethanolic solution was used with solvent/dry matter ratio (60/1–110/1), power (120–270 W), and time (0–10 min) as factors, while the responses studied were total phenolic and flavonoid contents. FTIR, TLC, DPPH, and FRAP anti-oxidants tests were used to characterize the extracts obtained with optimum conditions. The factors that significantly influenced both responses were the individual effect of all factors, the interaction between solvent/dry matter ratio and extraction time, the quadratic effect of solvent/dry matter ratio, and power for total phenolic content, while only the quadratic effect of power significantly influenced the flavonoid content. The highest contents of phenols (13.09 mg GAE/g) and flavonoid (7.39 mg CE/g) were obtained at 120 W for 0.16 min with a solvent/dry matter ratio of 60/1. ATR-FTIR spectra indicated the presence of polyphenolic compounds in the extract, namely flavonoids. TLC indicated the presence of at least nine compounds in the extract, among which catechin and quercetin were identified with respective Rf of 0.98 and 0.93. DPPH assay showed the anti-oxidant capacity for the extract with an IC50 of 194.98 µg/ml. RSM permitted us to develop a green protocol for maximum extraction of polyphenols from soybean seeds waste using less solvent, low power, and a reduced time in MAE.

Potential therapeutic interventions of plant-derived isoflavones against acute lung injury

Acute lung injury (ALI) is a life-threatening syndrome that possibly leads to high morbidity and mortality as no therapy exists. Several natural ingredients with negligible adverse effects have recently been investigated to possibly inhibit the inflammatory pathways associated with ALI at the molecular level. Isoflavones, as phytoestrogenic compounds, are naturally occurring bioactive compounds that represent the most abundant category of plant polyphenols (Leguminosae family). A broad range of therapeutic activities of isoflavones, including antioxidants, chemopreventive, anti-inflammatory, antiallergic and antibacterial potentials, have been extensively documented in the literature. Our review exclusively focuses on the possible anti-inflammatory, antioxidant role of botanicals'-derived isoflavones against ALI and their immunomodulatory effect in experimentally induced ALI. Despite the limited scope covering their molecular mechanisms, isoflavones substantially contributed to protecting from ALI via inhibiting toll-like receptor 4 (TLR4)/Myd88/NF-κB pathway and subsequent cytokines, chemokines, and adherent proteins. Nonetheless, future research is suggested to fill the gap in elucidating the protective roles of isoflavones to alleviate ALI concerning antioxidant potentials, inhibition of the inflammatory pathways, and associated molecular mechanisms.

Effects of Charcoal Rot on Soybean Seed Composition in Soybean Genotypes That Differ in Charcoal Rot Resistance under Irrigated and Non-Irrigated Conditions

Charcoal rot is a major disease of soybean (Glycine max) caused by Macrophomina phaseolina and results in significant loss in yield and seed quality. The effects of charcoal rot on seed composition (seed protein, oil, and fatty acids), a component of seed quality, is not well understood. Therefore, the objective of this research was to investigate the impact of charcoal rot on seed protein, oil, and fatty acids in different soybean genotypes differing in their charcoal rot susceptibility under irrigated and non-irrigated conditions. Two field experiments were conducted in 2012 and 2013 in Jackson, TN, USA. Thirteen genotypes differing in charcoal rot resistance (moderately resistant and susceptible) were evaluated. Under non-irrigated conditions, moderately resistant genotypes showed either no change or increased protein and oleic acid but had lower linolenic acid. Under non-irrigated conditions, most of the susceptible genotypes showed lower protein and linolenic acid but higher oleic acid. Most of the moderately resistant genotypes had higher protein than susceptible genotypes under irrigated and non-irrigated conditions but lower oil than susceptible genotypes. The different responses among genotypes for protein, oil, oleic acid, and linolenic acid observed in each year may be due to both genotype tolerance to drought and environmental conditions, especially heat differences in each year (2012 was warmer than 2013). This research showed that the increases in protein and oleic acid and the decrease in linolenic acid may be a possible physiological mechanism underlying the plant's responses to the charcoal rot infection. This research further helps scientists understand the impact of irrigated and non-irrigated conditions on seed nutrition changes, using resistant and susceptible genotypes.

Isoflavones derived from plant raw materials: bioavailability, anti-cancer, anti-aging potentials, and microbiome modulation

Isoflavones are secondary metabolites that represent the most abundant category of plant polyphenols. Dietary soy, kudzu, and red clover contain primarily genistein, daidzein, glycitein, puerarin, formononetin, and biochanin A. The structural similarity of these compounds to β-estradiol has demonstrated protection against age-related and hormone-dependent diseases in both genders. Demonstrative shreds of evidence confirmed the fundamental health benefits of the consumption of these isoflavones. These relevant activities are complex and largely driven by the source, active ingredients, dose, and administration period of the bioactive compounds. However, the preclinical and clinical studies of these compounds are greatly variable, controversial, and still with no consensus due to the non-standardized research protocols. In addition, absorption, distribution, metabolism, and excretion studies, and the safety profile of isoflavones have been far limited. This highlights a major gap in understanding the potentially critical role of these isoflavones as prospective replacement therapy. Our general review exclusively focuses attention on the crucial role of isoflavones derived from these plant materials and critically highlights their bioavailability, possible anticancer, antiaging potentials, and microbiome modulation. Despite their fundamental health benefits, plant isoflavones reveal prospective therapeutic effects that worth further standardized analysis.

Isoflavone profiles and antioxidant properties in different parts of soybean sprout

Sprouting is one of the processing methods to enhance bioavailability of some nutrients of agricultural products. Soybeans were germinated for 6 days and soybean (SB), soybean sprout (SBS), cotyledon of soybean sprout (CSS), and hypocotyl and root of soybean sprout (HRSS) were collected. Isoflavone profiles and in vitro antioxidant activities of 80% ethanol extracts of samples were analyzed. In addition, oxidative stability of the extract was evaluated in corn oils heated at 100 °C. The hypocotyl and root part of soybean sprout contained significantly (P < 0.05) higher content of isoflavone aglycones than the cotyledon part of soybean sprout. Diphenyl-1-picrylhydrazyl radial and 2,2'-azinobis(3-ethylbenzothiazoline-6-sul-fonic acid cation radical scavenging activities of SBS were 1.6 and 1.3 times higher than those of SB, respectively (P < 0.05), whereas those of CSS were 1.1 and 1.8 times higher than those of HRSS, respectively (P < 0.05). CSS had higher ORAC and FRAP values than others. High correlations between contents of total flavonoids and antioxidant activities were observed in all in vitro antioxidant assays. SBS, CSS, and HRSS had significantly higher oxidative stability than SB in 100 °C heated corn oil after 9 hr treatment (P < 0.05). Generally, 80% ethanol extract of CSS had high in vitro antioxidant properties whereas HRSS had high aglycone forms of isoflavones. Isoflavone aglycones may not be major ingredients providing antioxidant activities of soybean sprout. PRACTICAL APPLICATION: Soybeans are important crops for the preparation of tofu, soymilk, and protein sources. Soybean sprout prepared by germinating soybean and growing for several days is one of important food materials used as daily diet in some countries. In this study, antioxidant activities of different parts of soybean sprouts were evaluated using in vitro methods and bulk oil model systems. In addition, isoflavone profiles of soybean sprouts were determined. Enhanced antioxidant activities of soybean sprouts may help consumers choose healthier foods and extend business areas of the soybean food industry.

Effect of biotic and abiotic elicitors on isoflavone biosynthesis during seed development and in suspension cultures of soybean (Glycine max L.)

The present investigation aimed to look at the effects of biotic and abiotic elicitors during Soybean seed development and cell suspension culture in isoflavones accumulation. The expression levels of four major genes viz., CHS7, CHS8, IFS2, and IFS1 involved on isoflavones biosynthesis during seed developmental stages from R5L-R7 was seen in both MAUS-2 and JS-335 Soybean varieties. The R7 stage showed 1.24-fold upregulation of IFS1transcript level and considered as the control for Soybean seed development. Both varieties during R6-R8 stages responded differently to the foliar application of 10 µM SA, 10 µM MJ and 0.1% Aspergillus niger. The IFS2 transcripts were upregulated by SA at the R7 stage with 5.21- and 4.68-fold in JS-335 and MAUS-2, respectively. IFS1 expression was significantly increased by A. niger treatment at R7 stage with 3.98- and 3.21-fold in MAUS-2 and JS-335, respectively. The expression of CHS7 and CHS8 by 10 μM SA at R7 level revealed maximum up-regulation of 0.51- and 1.01-fold in MAUS-2; 0.37- and 0.82-fold in JS-335, respectively. In the soybean callus suspension culture, biosynthetic genes were used to validate the effects of elicitor on isoflavones. Both biotic and abiotic treatments contribute to the upregulation of IFS1 and IFS2 expression, that in turn, leads to the accumulation of isoflavone in seed development as well as in suspension cultures. These data further suggested that the IFS2 is the key gene responsible for the isoflavone accumulation during elicitor treatment.

Equivalence Test between the Physicochemical Properties of Transgenic and Non-Transgenic Soy Flour

Soybeans are a source of plant-based protein with a fairly complete composition of essential amino acids. Most of the soybean raw material in Indonesia originates from the United States of America where around 75% of the soybeans are transgenic soybeans (Roundup Ready GMO). One of the easily produced and practical soybean products is soy flour. The purpose of this study was to compare the physicochemical properties of flour made from three types of soybeans: local soybeans, imported transgenic soybeans, and imported non-transgenic soybeans. The study was conducted in two phases: the preliminary study, where the physicochemical properties of the three varieties of soybeans were assessed, and the main study which involved the production of soy flour and the analysis of their physicochemical properties. The results of the preliminary analysis revealed that the local soybeans had greater length and width dimensions, volume, bulk density, 100-seed weight, and protein content than transgenic and imported non-transgenic soybeans. The statistical analysis demonstrated that soybean variety had a significant effect on the physicochemical properties of the flour produced, namely the yield, color, water activity, bulk density, repose angle, moisture, ash, protein, fat, and mineral content, and the antioxidant capacity parameters. On the other hand, soybean variety did not have a significant effect on the carbohydrate and total phenolic content. Based on the physicochemical properties, local soy flour had a number of properties that were equivalent to those of imported soy flour and was even superior in its protein content and antioxidant capacity.

Plant growth promoting rhizobacterium Stenotrophomonas maltophilia BJ01 augments endurance against N2 starvation by modulating physiology and biochemical activities of Arachis hypogea

Arachis hypogea (Peanut) is one of the most important crops, and it is harvested and used for food and oil production. Being a legume crop, the fixation of atmospheric nitrogen is achieved through symbiotic association. Nitrogen deficiency is one of the major constrains for loss of crop productivity. The bacterium Stenotrophomonas maltophilia is known for interactions with plants. In this study, characteristics that promote plant growth were explored for their ability to enhance the growth of peanut plants under N2 deficit condition. In the presence of S. maltophilia, it was observed that fatty acid composition of peanut plants was influenced and increased contents of omega-7 monounsaturated fatty acid and omega-6 fatty acid (γ-Linolenic acid) were detected. Plant growth was increased in plants co-cultivated with PGPR (Plant Growth Promoting Rhizobacteria) under normal and stress (nitrogen deficient) condition. Electrolyte leakage, lipid peroxidation, and H2O2 content reduced in plants, co-cultivated with PGPR under normal (grown in a media supplemented with N2 source; C+) or stress (nitrogen deficient N+) conditions compared to the corresponding control plants (i.e. not co-cultivated with PGPR; C-or N-). The growth hormone auxin, osmoprotectants (proline, total soluble sugars and total amino acids), total phenolic-compounds and total flavonoid content were enhanced in plants co-cultivated with PGPR. Additionally, antioxidant and free radical scavenging (DPPH, hydroxyl and H2O2) activities were increased in plants that were treated with PGPR under both normal and N2 deficit condition. Overall, these results indicate that plants co-cultivated with PGPR, S. maltophilia, increase plant growth, antioxidant levels, scavenging, and stress tolerance under N2 deficit condition. The beneficial use of bacterium S. maltophilia could be explored further as an efficient PGPR for growing agricultural crops under N2 deficit conditions. However, a detail agronomic study would be prerequisite to confirm its commercial role.

Consumption of Decorticated Pulses Ensures the Optimum Intake of Isoflavones by the Urban Indian Population

Sample urban population was assessed for consumption of legumes. Genistein and daidzein content of commonly consumed legumes was evaluated to estimate the isoflavone intake through the consumption of these legumes by selected population. Total genistein content of all legumes considered for analysis was found to be in the range of 0.60 to 8.65 mg per 100 g whereas total daidzein content was found to be in the range of 1.10 to 30.37 mg per 100 g in selected legumes. Chickpea, kabuli, whole (Cicer arietinum), pigeon pea, split, decorticated (Cajanus cajan), chickpea, split, decorticated (Cicer arietinum) showed a high amount of genistein and daidzein among selected legumes. Average isoflavone consumption by selected population was found to be 18.22 mg/d through the consumption of legumes. Consumption of pigeon pea (split, decorticated) and chickpea (split, decorticated) was found to be highest at 371.6 g/month and 329.7 g/month, and hence were found to contribute 18% and 14% to total isoflavone intake, respectively. The comparatively high content of isoflavones and inclusion as a staple in the diet have resulted in making the split, decorticated pulses (chickpea, pigeon pea, lentil, green gram, black gram) a chief isoflavone source for selected population irrespective of their demographic differences.

LC-ESI-MS based characterisation of isoflavones in soybean (Glycine max (L.) Merr.) from India

A total of twenty-one soybean varieties were screened for their morphological characteristics followed by isoflavone content analysis by HPLC. The total isoflavone (TI) content was found within a wide range of 140.9-1048.6 μg/g of soy in different varieties. The highest isoflavone content was found in MAUS-2 followed by DS_2613 and lowest in Karunae (140.9 μg/g of soy). Various isoflavone forms were identified by LC-ESI⁺ MS. Significant differences in the isoflavone content were observed for all the aglycones and their glucoside conjugates as well as total daidzein, total genistein, total glycitein, and TI. A positive correlation between TI content and growth stages was found during the progression of seed development. An increase of 5.4-fold and 5.3-fold of TI concentration was observed for JS 335 and MAUS-2 respectively, from early to green mature (R5-R8) stage of bean development.

Rapid characterization of metabolites in soybean using ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) and screening for α-glucosidase inhibitory and antioxidant properties through different solvent systems

This work was the first to investigate on the simultaneous characterization of metabolite profiles in soybean using UPLC-ESI-Q-TOF-MS/MS. Twenty two compositions were observed within 14 min from the methanol extract and confirmed as twelve isoflavones of three types and ten soyasaponins (Ab, Af, I-III, αg, βg, βa, γg, and γa). Moreover, the patterns of two chemicals showed considerable differences in seven solvent systems by HPLC analysis and their optimal extraction was achieved by 70% methanol (isoflavone: 4102.69 μg/g; soyasaponin: ten peaks). The second abundant isoflavones were detected in 50% methanol (4054.39 μg/g), followed by 30% methanol, 100% methanol, 10% methanol, CH2Cl2, and acetone extracts with 3134.03, 2979.49, 1681.33, 366.19, and 119.00 μg/g, respectively. Soyasaponins exhibited similar tendencies as those of isoflavones. The highest total phenolic was found as 2.10 ± 0.05 mg GAE/g in 70% methanol with remarkable differences by comparing other extracts. Specifically, this extract showed potent α-glucosidase inhibitory (81%) and antioxidant capacities (DPPH: 93% and ABTS: 95%) at a concentration of 1.0 mg/mL. Our results may be contributed to enhancing the value to functional foods and evaluating the secondary metabolites concern to antioxidant properties using solvent system in soybean.

Simultaneous Determination of Soyasaponins and Isoflavones in Soy (Glycine max L.) Products by HPTLC-densitometry-Multiple Detection

A new high-throughput method was developed for the simultaneous analysis of isoflavones and soyasaponnins in Soy (Glycine max L.) products by high-performance thin-layer chromatography with densitometry and multiple detection. Silica gel was used as the stationary phase and ethyl acetate:methanol:water:acetic acid (100:20:16:1, v/v/v/v) as the mobile phase. After chromatographic development, multi-wavelength scanning was carried out by: (i) UV-absorbance measurement at 265 nm for genistin, daidzin and glycitin, (ii) Vis-absorbance measurement at 650 nm for Soyasaponins I and III, after post-chromatographic derivatization with anisaldehyde/sulfuric acid reagent. Validation of the developed method was found to meet the acceptance criteria delineated by ICH guidelines with respect to linearity, accuracy, precision, specificity and robustness. Calibrations were linear with correlation coefficients of >0.994. Intra-day precisions relative standard deviation (RSD)% of all substances in matrix were determined to be between 0.7 and 0.9%, while inter-day precisions (RSD%) ranged between 1.2 and 1.8%. The validated method was successfully applied for determination of the studied analytes in soy-based infant formula and soybean products. The new method compares favorably to other reported methods in being as accurate and precise and in the same time more feasible and cost-effective.

Seed Nutrition and Quality, Seed Coat Boron and Lignin Are Influenced by Delayed Harvest in Exotically-Derived Soybean Breeding Lines under High Heat

The timing of harvest is a major factor affecting seed quality in soybean, particularly in Midsouthern USA, when rain during harvest period is not uncommon. The objective of this research was to evaluate the effects of time of harvest on soybean seed quality (seed composition, germination, seed coat boron, and lignin) in high germinability (HG) breeding lines (50% exotic) developed under high heat. The hypothesis was that seeds of HG lines possess physiological and genetic traits for a better seed quality at harvest maturity and delayed harvest. A 2-year field experiment was conducted under irrigated conditions. Results showed that, at harvest maturity, the exotic HG lines had higher seed protein, oleic acid, sugars, seed coat boron, and seed coat lignin, but lower seed oil compared with the non-exotic checks (Control), confirming our hypothesis. At 28 days after harvest maturity (delayed harvest), the content of seed protein, oleic acid, sugars, seed coat boron, and seed coat lignin were higher in some of the HG lines compared with the checks, indicating a possible involvement of these seed constituents, especially seed coat boron and seed coat lignin, in maintaining seed coat integrity and protecting seed coat against physical damage. Highly significant positive correlations were found between germination and seed protein, oleic acid, sugars, and seed coat boron and seed coat lignin. Highly significant negative correlation was found between germination and oil, linoleic acid, seed coat wrinkling, shattering, and hard seed. Yields of some HG lines were competitive with checks. This research demonstrated that time of harvesting is an important factor influencing seed protein and oil production. Also, since high oleic acid is desirable for oxidative stability, shelf-life and biodiesel properties, using HG lines could positively influence these important traits. This result should suggest to breeders of some of the advantages of selecting for high seed coat boron and lignin, and inform growers of the importance of timely harvest for maintaining high seed quality.

Comparison of nutritional components (isoflavone, protein, oil, and fatty acid) and antioxidant properties at the growth stage of different parts of soybean [Glycine max (L.) Merrill]

This is the first study to investigate antioxidant capacities of isoflavones prepared using microwave-assisted hydrolysis method from different parts (seeds, leaves, leafstalks, pods, stems and roots) of soybean at growth stages. In addition, the fluctuations in the isoflavone, protein, fatty acid, and oil contents in R6-R8 (R6: beginning; R7: beginning maturity; R8: full maturity) seeds were confirmed. The R7 seeds exhibited the most predominant contents of isoflavones (1218.1±7.3 μg/g) in the following order: daidzein (48%)>genistein (35%)>glycitein (17%). The second highest isoflavone content was found in the leaves (1052.1±10.4 μg/g), followed by R8 seeds>roots>R6 seeds>leafstalks> pods; the stems exhibited the lowest isoflavone content (57.2±1.7 μg/g). Interestingly, daidzein showed the highest individual isoflavone content with remarkable variations (57.2-766.8 μg/g), representing 46-100% of the total isoflavone content. R8 exhibited higher protein, fatty acid, and oil contents than R6 or R7. Moreover, the antioxidant capacities against two radicals in different parts of soybean plant showed considerable differences depending upon the isoflavone content. Our results suggested that soybean leaves and seeds might be useful materials for functional foods.

Laser light and magnetic field stimulation effect on biochemical, enzymes activities and chlorophyll contents in soybean seeds and seedlings during early growth stages

Laser and magnetic field bio-stimulation attracted the keen interest of scientific community in view of their potential to enhance seed germination, seedling growth, physiological, biochemical and yield attributes of plants, cereal crops and vegetables. Present study was conducted to appraise the laser and magnetic field pre-sowing seed treatment effects on soybean sugar, protein, nitrogen, hydrogen peroxide (H2O2) ascorbic acid (AsA), proline, phenolic and malondialdehyde (MDA) along with chlorophyll contents (Chl "a" "b" and total chlorophyll contents). Specific activities of enzymes such as protease (PRT), amylase (AMY), catalyst (CAT), superoxide dismutase (SOD) and peroxides (POD) were also assayed. The specific activity of enzymes (during germination and early growth), biochemical and chlorophyll contents were enhanced significantly under the effect of both laser and magnetic pre-sowing treatments. Magnetic field treatment effect was slightly higher than laser treatment except PRT, AMY and ascorbic acid contents. However, both treatments (laser and magnetic field) effects were significantly higher versus control (un-treated seeds). Results revealed that laser and magnetic field pre-sowing seed treatments have potential to enhance soybean biological moieties, chlorophyll contents and metabolically important enzymes (degrade stored food and scavenge reactive oxygen species). Future study should be focused on growth characteristics at later stages and yield attributes.

Phytochemical profiling of underexploited Fabaceae species: Insights on the ontogenic and phylogenetic effects over isoflavone levels

There is an increasing trend towards finding alternative sources of valued phytochemicals due to their diverse potentialities in food industry and pharmaceutical applications. Phenolic compounds, in particular, have been the focus of several profiling reports, but isoflavones characterization has been studied in fewer cases and in a very limited group of plant species. Despite their acknowledged bioactivity, there's actually a strict number of plants validated for their isoflavones contents. In a previous report, we have identified nine Leguminosae species (from genera Biserrula, Lotus, Ornithopus and Scorpiurus) as potential alternative sources of these phenolic compounds. However, the isoflavone profiles are highly modulated by the ontogenic stage. Therefore, the present study was conducted in the same Leguminosae species, but harvested at three sequential vegetative development stages: vegetative elongation, late bud and late flowering, with the main purpose of assessing the evolution of isoflavones content throughout the plant development. In general, the plant species from Biserrula and Lotus genera showed the highest potential as new natural sources of isoflavones, especially owing their high levels of biochanin A. Independently of the plant species, it was possible to identify the phenologic stages where each of the quantified isoflavones is maximized. These findings are useful to predict isoflavone yields according to harvesting time, validating the potential use of the studied plants in innovative food formulations.

Antioxidant and antimicrobial activity of natural phenolic extract from defatted soybean flour by-product for stone fruit postharvest application

BACKGROUND

Fresh fruit is highly perishable during storage and transport, so there has been growing interest in finding safe and natural antimicrobial compounds as a control tool. Phenolic compounds are secondary metabolites naturally present in vegetable material and have been associated with antimicrobial and antioxidant properties. Therefore, the aim of this study was to investigate the antioxidant capacity and potential antimicrobial effect of phenolic extract obtained from defatted soybean flour against selected pathogenic bacteria and microorganisms responsible of fruit decay.

RESULTS

Analysis of phenolic composition by HPLC-MS showed the presence of a wide range of compounds, with isoflavones and phenolic acids the main polyphenols identified. Furthermore, the phenolic extract had important antioxidant activity by two different assays. Related to antimicrobial activity, in vitro experiments demonstrated that phenolic extract displayed a high activity against the main foodborne pathogens, while a moderate inhibition was found against five spoilage yeasts and Monilia laxa and a scarce effect for Penicillium glabrum, Cladosporium uredinicola and Botrytis cinerea. Interestingly these compounds considerably inhibited the mycelial growth of Monilia laxa, in both in vitro and in vivo experiments.

CONCLUSION

The results of the present study revealed that defatted soybean flour is an important source of phenolic compounds with remarkable antimicrobial and antioxidant activity, suggesting the possibility of using them as natural additives in postharvest treatments to extend the shelf life of fruit.

Isoflavone Augmentation in Soybean Cell Cultures Is Optimized Using Response Surface Methodology

Glycine max contains potential therapeutic isoflavones, and its productivity in plants is considerably influenced worldwide by several biotic and abiotic factors. Optimization of soybean cell suspension cultures (Indian variety, JS 335) to maximize the cell growth and isoflavone production in the present study was performed using response surface methodology (RSM) with three independent variables of plant growth regulators, 2,4-dichlorophenoxyacetic acid (2,4-D), 1-naphthalene acetic acid (α-NAA), and kinetin (Kn). The maximum biomass achieved was 70.62 g/L dry weight (dw) using the optimized medium of 2.10 mg/L 2,4-D, 5.52 mg/L α-NAA, and 0.35 mg/L Kn supplemented in the Murashige and Skoog (MS) basal medium. The total isoflavone content of 38.59 mg/g of dw was obtained in the medium with optimized conditions of 1.33 mg/L 2,4-D, 1.76 mg/L α-NAA, and 0.15 mg/L Kn. In comparison to field-grown soybean seeds, the cell suspension cultures profoundly augmented isoflavone concentrations. The optimized conditions for both biomass and total isoflavone content were evaluated by superimposing the contour plots. The results suggested that the optimized medium of cell suspension cultures possibly be used for scale-up studies in bioreactors to offer a high content of bioactive isoflavones.

Inoculation with Bradyrhizobium japonicum enhances the organic and fatty acids content of soybean (Glycine max (L.) Merrill) seeds

Soybean (Glycine max (L.) Merrill) is one of the most important food crops for human and animal consumption, providing oil and protein at relatively low cost. The least expensive source of nitrogen for soybean is the biological fixation of atmospheric nitrogen by the symbiotic association with soil bacteria, belonging mainly to the genus Bradyrhizobium. This study was conducted to assess the effect of the inoculation of G. max with Bradyrhizobium japonicum on the metabolite profile and antioxidant potential of its seeds. Phenolic compounds, sterols, triterpenes, organic acids, fatty acids and volatiles profiles were characterised by different chromatographic techniques. The antioxidant activity was evaluated against DPPH, superoxide and nitric oxide radicals. Inoculation with B. japonicum induced changes in the profiles of primary and secondary metabolites of G. max seeds, without affecting their antioxidant capacity. The increase of organic and fatty acids and volatiles suggest a positive effect of the inoculation process. These findings indicate that the inoculation with nodulating B. japonicum is a beneficial agricultural practice, increasing the content of bioactive metabolites in G. max seeds owing to the establishment of symbiosis between plant and microorganism, with direct effects on seed quality.

Changes in L-phenylalanine ammonia-lyase activity and isoflavone phytoalexins accumulation in soybean seedlings infected with Sclerotinia sclerotiorum

Soybean [Glycine max (L.) Merr.] cultivars (Meli, Alisa, Sava and 1511/99) were grown up to V1 phase (first trifoliate and one node above unifoliate) and then inoculated with Sclerotinia sclerotiorum (Lib.) de Bary under controlled conditions. Changes in L-phenylalanine ammonia-lyase (PAL) activity and isoflavone phytoalexins were recorded 12, 24, 48 and 72 h after the inoculation. Results showed an increase in PAL activity in all four examined soybean cultivars 48 h after the inoculation, being the highest in Alisa (2-fold higher). Different contents of total daidzein, genistein, glycitein and coumestrol were detected in all samples. Alisa and Sava increased their total isoflavone content (33.9% and 6.2% higher than control, respectively) as well as 1511/99, although 48 h after the inoculation its content decreased significantly. Meli exhibited the highest rate of coumestrol biosynthesis (72 h after the inoculation) and PAL activity (48 h after the inoculation). All investigated cultivars are invariably susceptible to this pathogen. Recorded changes could point to possible differences in mechanisms of tolerance among them.

Comparison of isoflavones and anthocyanins in soybean [Glycine max (L.) Merrill] seeds of different planting dates

The concentrations of isoflavones and anthocyanins in five soybean seed cultivars of three different planting dates were determined in this study. Among the seeds of three different planting dates, the highest concentration of average total isoflavones (4098 μg g(-1)) was measured in those from early July, whereas the lowest concentration of average total isoflavones (3238 μg g(-1)) was measured in those from late May. Anthocyanin compounds were detected only in the Cheongjakong 3 cultivar. Among the three different planting dates, late-planted Cheongjakong 3 accumulated the highest concentration of total anthocyanins (10103 μg g(-1)), whereas the variety at an earlier planting date exhibited the lowest concentration of average total anthocyanins (7115 μg g(-1)). On the basis of these results, it was concluded that environmental factors such as temperature and precipitation may change the isoflavone and anthocyanin contents of soybean, altering the nutritional values of soy products.

Chip-based nanoflow high performance liquid chromatography coupled to mass spectrometry for profiling of soybean flavonoids

In this work a chip-based nano HPLC coupled MS (HPLC-chip/MS) method with a simple sample preparation procedure was developed for the flavonoid profiling of soybean. The analytical properties of the method including the linearity (R(2) , 0.992-0.995), reproducibility (RSD, 1.50-7.66%), intraday precision (RSD, 1.41-5.14%) and interday precision (RSD, 2.76-16.90%) were satisfactory. Compared with the conventional HPLC/MS method, a fast extraction and analysis procedure was applied and more flavonoids were detected in a single run. Additionally, 13 flavonoids in soybean seed were identified for the first time. The method was then applied to the profiling of six varieties of soybean sowed at the same place. A clear discrimination was observed among different cultivars, three isoflavones, accounting for nearly 80% of total flavonoid contents, were found increased in the spring soybeans compared with the summer cultivars.