Soy Foods Research Articles

Effect of the Intake of Isoflavones on Risk Factors of Breast Cancer-A Systematic Review of Randomized Controlled Intervention Studies.

Epidemiological studies suggest that high intake of soy isoflavones may protect against breast cancer, but causal relationships can only be established by experimental trials. Thus, we aimed to provide a systematic review of randomized controlled trials (RCTs) on the effect of an isoflavone intake on risk factors of breast cancer in healthy subjects. After a systematic literature search in PubMed, 18 different RCTs with pre- and/or postmenopausal women were included and investigated for details according to the PRISMA guideline. In these studies, isoflavones were provided by soy food or supplements in amounts between 36.5–235 mg/d for a period of 1–36 months. Breast density, estrogens including precursors, metabolites, estrogen response such as length of menstrual cycle, and markers of proliferation and inflammation were considered. However, in most studies, differences were not detectable between isoflavone and control/placebo treatment despite a good adherence to isoflavone treatment, irrespective of the kind of intervention, the dose of isoflavones used, and the duration of isoflavone treatment. However, the lack of significant changes in most studies does not prove the lack of effects as a sample size calculation was often missing. Taking into account the risk of bias and methodological limitations, there is little evidence that isoflavone treatment modulates risk factors of breast cancer in pre- and postmenopausal women. Future studies should calculate the sample size to detect possible effects and consider methodological details to improve the study quality.

Food sources of dietary fibre and risk of total knee replacement related to severe osteoarthritis, the Singapore Chinese Health Study

ObjectivesWe aimed to evaluate the association between fibre intake and its food sources, and the risk of total knee replacement (TKR) due to severe knee osteoarthritis (KOA).MethodsWe used data from...

Natto and miso: an overview on their preparation, bioactive components and health-promoting effects

Natto and miso are two major traditional fermented soy foods in Japan. Natto is prepared by fermenting cooked soybeans with Bacillus subtilis natto. The beans of natto have a sticky outlook, slippery texture, sour aroma and nutty flavour. Bioactive components of natto are nattokinase, bacillopeptidase F, vitamin K2, dipicolinic acid and γ-polyglutamic acid. Miso is a fermented soybean paste widely used to make miso soup. The paste is produced by fermenting cooked soybeans with koji (steamed rice inoculated with Aspergillus oryzae). Bioactive compounds of miso include isoflavones and phenolic acids. In this review, the preparation, bioactive components, and health-promoting properties of natto and miso are highlighted. Sources of information referred were from Google Scholar, J-Stage, Science Direct, PubMed, PubMed Central and PubChem

Legume Consumption and Gut Microbiome in Elderly Chinese Men and Women.

Legumes, important components of a healthy diet, may exert their health benefits through the influence of the gut microbiome. However, this hypothesis has not been well investigated. This study aimed to examine the associations between long-term legume consumption and the gut microbiome among elderly Chinese. The gut microbiome was profiled by 16S ribosomal RNA sequencing in 2302 Chinese adults enrolled in 2 large cohort studies, the Shanghai Women's Health Study and Shanghai Men's Health Study. Legume consumption, including peanuts, soy foods, and other beans, was assessed by food-frequency questionnaires prior to the stool collection. The associations of legume consumption with microbiome diversity and taxa abundance were evaluated by linear or negative binomial hurdle models, adjusting for sociodemographics, lifestyle factors, and BMI. False discovery rate (FDR)-corrected P values (PFDR) < 0.1 were considered significant. Respectively, 52% and 48% of study participants were male and female. The mean age at stool collection was 68.03 y for females and 70.28 y for males. Total legume consumption was not associated with gut microbiome ɑ-diversity; however, male peanut consumers had a higher Chao1 index (β = 22.52, P=0.01), whereas peanut consumption was associated with decreased Shannon (β = -0.03, P=0.02) and Simpson (β = -0.002, P=0.04) indexes among females. In female and male combined analyses, total legume consumption was associated with increased Enterobacteriales (β = 0.30, PFDR=0.06). Within this order, an unclassified genus in the family Enterobacteriaceae was positively associated with total legume (β = 0.46, PFDR=0.03) and peanut (β = 0.59, PFDR=0.01) consumption. Stratified analyses showed significant associations were primarily confined to females and participants without metabolic conditions. Legume consumption was associated with gut microbiome diversity and abundance of some bacteria in elderly Chinese. Associations were significant only among 1 sex group. Further research, including large-scale prospective studies and feeding trials, is needed to fully understand the role of the gut microbiome in legume-health associations.

Longer-Term Soy Nut Consumption Improves Vascular Function and Cardiometabolic Risk Markers in Older Adults: Results of a Randomized, Controlled Cross-Over Trial

Abstract Objectives Soy foods may contribute to the beneficial effects of plant-based diets on cardiovascular disease (CVD) risk. However, their effects on vascular function have hardly been investigated. The objective was to investigate if longer-term soy nut consumption improves vascular function and cardiometabolic health in older adults. Methods Twenty-three apparently healthy participants (60–70 years; BMI between 20–30 kg/m2) participated in a randomized, controlled, single-blinded cross-over trial with an intervention (67 g of soy nuts daily providing 25.5 g soy protein) and control period (no nuts) of 16 weeks, separated by eight weeks wash-out. Volunteers followed the Dutch food-based dietary guidelines. At baseline and at 8 and 16 weeks anthropometric measurements and fasting blood samples were collected. Markers of vascular function (i.e., endothelial function, arterial stiffness, and microvascular structure) were assessed at week 16. Results No serious adverse events were reported and the soy nut regime was well tolerated. Body weight remained stable. Serum isoflavone concentrations, a marker of compliance, increased after the intervention period (daidzein: 128.3 ng/mL; 95% CI: 72.6–183.9 ng/mL; P &amp;lt; 0.001 and genistein: 439.8 ng/mL 95% CI: 246.7–632.9 ng/mL; P &amp;lt; 0.001). The brachial artery flow-mediated vasodilation (FMD) response increased by 1.49 pp (95% CI: 0.03–2.95 pp; P = 0.046) following the soy intervention, but no effect was found on the carotid artery reactivity (CAR) response. Arterial stiffness, assessed by carotid-to-femoral pulse wave velocity (PWVc-f), was unchanged. Retinal arteriolar calibers (CRAE), a measure for microvascular structure, tended to improve by 1.42 mm (95% CI: −0.05–2.90 mm; P = 0.059). Soy consumption also lowered serum LDL-cholesterol concentrations by 0.17 mmol/L (95% CI: 0.02–0.32 mmol/L; P = 0.027). HDL-cholesterol and triacylglycerol (TAG) did not change. Finally, office SBP and DBP decreased by 4 mmHg (95% CI: 0–8 mmHg; P = 0.034) and 2 mmHg (95% CI: 1–4 mmHg; P = 0.005), respectively. Conclusions A longer-term daily intake of soy nuts improved endothelial function, office blood pressure, and serum LDL-cholesterol concentrations, suggesting mechanisms by which an increased soy food intake beneficially affects CVD risk in older adults. Funding Sources This study was supported by a grant from the Alpro Foundation.

New-onset vegetarian diet shows differences in fatty acid metabolites in European American and African American women

Background and aimsThe type of fat consumed in animal-based western diets, typically rich in the saturated fat palmitate, has been implicated in cardiometabolic disease risk. In contrast, the most abundant mono- and polyunsaturated fats, more typical in a vegetarian or plant-based diet, potentiate less deleterious effects. This study determined differences in plasma and urine metabolites when switching from omnivorous to vegetarian diet, including metabolites involved in fatty acid utilization. Methods and resultsA prospective cohort of 38 European (EA) and African American (AA) omnivorous females were matched by age (25.7 ± 5.3y) and BMI (22.4 ± 1.9 kg/m2). Pre-intervention samples were collected while subjects consumed habitual animal-based diet. Changes in metabolites were assessed by ultra-high-performance liquid chromatography-tandem mass spectroscopy (Metabolon, Inc.) upon completing four days of novel vegetarian diet provided by the Vanderbilt Metabolic Kitchen. Changes in several diet-derived metabolites were observed, including increases in compounds derived from soy food metabolism along with decreases in metabolites of xanthine and histidine. Significant changes occurred in metabolites of saturated, monounsaturated and polyunsaturated fatty acids along with significant differences between EA and AA women in changes in plasma concentrations of acylcarnitines, which reflect the completeness of fatty acid oxidation (versus storage). ConclusionThese data suggest improvements in fatty acid metabolism (oxidation vs storage), a key factor in energy homeostasis, may be promoted rapidly by adoption of a vegetarian (plant-based) diet. Mechanistic differences in response to diet interventions must be understood to effectively provide protection against the widespread development of obesity and cardiometabolic disease in population subgroups, such as AA women.

Optimization of the Bioactivation of Isoflavones in Soymilk by Lactic Acid Bacteria

Soybeans and soy-based products contain isoflavones which can be used for nutraceutical and medical applications. In soybeans and in unfermented soy foods, isoflavones are normally present as glycosides. Isoflavone glycosides can be enzymatically converted to isoflavone aglycones, thus releasing the sugar molecule. The effective absorption of isoflavones in humans requires the bioconversion of isoflavone glycosides to isoflavone aglycones through the activity of the enzyme β-glucosidase. The objective was to assess the capacity of 42 bacterial strains (belonging to Lactobacillus, Streptococcus and Enterococcus) to produce β-glucosidase activity. The strain that showed the highest β-glucosidase activity (Lactobacillus plantarum 128/2) was then used for the optimization of the bioconversion of genistin and daidzin present in commercial soymilk to their aglycone forms genistein and daidzein. The contribution of process parameters (temperature, inoculum size, time) to the efficiency of such bioactivation was tested. Lactobacillus plantarum 128/2 was able to completely bioactivate soymilk isoflavones under the following conditions: 25 °C temperature, 2% inoculum size and 48 h process time. These results confirm the suitability of lactic acid bacteria for the bioactivation of isoflavones present in soymilk and provide an interesting candidate (L. plantarum 182/2) for food industries to perform this transformation.

Selar (Selar crumenophthalmus) Fish Protein Hydrolysate Has Antidiabetic Properties Possibly through GLP-1

Background : Enzymatic hydrolysis of fish protein using protease or fish protein hydrolysate can form bioactive peptides that have antidiabetic activity. One potential mechanism of fish protein hydrolysate is reducing blood glucose through increased endogenous glucagon like peptide (GLP)-1 production. Tempeh is soy fermented food that has protease which is potential biocatalyst in producing fish protein hydrolysate. Objective: To evaluate the antidiabetic properties of Selar (Selar crumenophthalmus) fish protein hydrolysate using tempeh protease as biocatalyst and duodenal gene expression of GLP-1. Methods: Selar fish protein isolate was digested for 8 hours at 37°C using crude tempeh protease. Diabetes mellitus was induced in rats by intraperitoneal injection of streptozotosin (65 mg/kg bw) and nicotinamide (230 mg/kg bw). Fish protein isolate and hydrolysate in dose of 300 mg/bw and 500 mg/ bw were orally administered daily for 4 weeks. Blood was drawn for fasting serum glucose and lipid profile analysis. Total RNAs were isolated from duodenum and quantitative real time PCR was performed to quantify mRNA expression of GLP-1. Data were analyzed using one way ANOVA and gene expression analysis were performed using Livak. Results and Discussion: There is a significant difference on fasting serum glucose, total cholesterol, triglyceride, LDL-cholesterol, HDL-cholesterol and duodenal GLP-1 mRNA expression level between groups (p&lt;0.05). The duodenal GLP-1 mRNA expression was the highest in rats who received hydrolyzed fish protein 500 mg/ bw. Conclusion: Hydrolysis of selar fish protein using tempeh protease has anti-diabetic properties possibly through GLP-1 production.

A Review based study on Soymilk: Focuses on production technology, Prospects and Progress Scenario in last Decade

Soy food has been consumed for more than a thousand years, but only in the last 15 years they have made way for Western cultures and diets. Soymilk is a cheap, decent protein source that does not contain lactose. It replaces bovine milk as well. Though, soy milk protein is less digestible and more anti-nutrient than milk protein, it resolves the lactose intolerance problem and acts as a vegan milk supply. Soy milk is typically divided into two categories: fermented and unfermented. In comparison with unfermented one, fermented soy milk is less favorable. But there are also some inconveniences, such as low stability, shorter shelf-life and anti-nutritional causes. Different technology should overcome all these disadvantages such as Ultra high temperature, Microwave processing, Ultra-high pressure homogenization, Pulsed electric field and High pressure processing. Besides both of these soy milk, bioactive compounds like isoflavones, genistein, daidzein, and glycitein can also be minimized by thermal processing. A brief description of the importance, production technology, nutritional properties and development concerns over the decade has been discussed in this article.

English

Soybean is a food crop with a growing interest in Benin. This study aims to provide insight about the main quality characteristics of the grain preferred by small-scale soy processors and the main socio-economic factors which drive their preferences. 116 small-scale processors related to three main soy food products - &ldquo;Soy Amon&rdquo; (soy cheese), &ldquo;Soy Afitin&rdquo; (soya fermented condiment) and &ldquo;soymilk&rdquo; - were asked to express their preferences about important soybean grain properties regarding their activity. Collected data were processed using a conjoint based preference analysis. &ldquo;Density of the grain&rdquo; appears to be an important quality criterion for the processors, whatever the soybean food produced. Less important attributes are &ldquo;use of inoculant&rdquo;, &ldquo;use of fertilizer&rdquo;, &ldquo;soybean production origin&rdquo;, &ldquo;soybean provider&rdquo;, depending on the soy food produced. Moreover, soy Afitin producers dislike soy grain distributed by &ldquo;individual farmers&rdquo; and prefer &ldquo;support organization&quot; as providers, in contrast to soy cheese and soymilk producers. Regarding the social and economic factors influencing the processors&rsquo; preferences for grain provided by farmers, processors whose main activity is &ldquo;merchant&rdquo; are probably not favorable to soy sold by farmers and the higher the purchase frequency is, the more the processor is likely to buy soy from farmers. Key words: Soybean, grain, small-scale processing, preferences, criteria, conjoint analysis.

Association between Soy Food and Dietary Soy Isoflavone Intake and the Risk of Cardiovascular Disease in Women: A Prospective Cohort Study in Korea.

The association between soy food and soy isoflavone intake and cardiovascular disease (CVD) risk is uncertain, especially in women. We aimed to investigate this association in Korean women. We analyzed data from the Korean Genome and Epidemiology Study, including 4713 Korean women aged 40–69 years with no CVD or cancer at baseline. Dietary information was obtained using a validated semi-quantitative food frequency questionnaire, and the incidence of CVD was assessed using biennial self-reported questionnaires on medical history. The mean follow-up time was 7.4 years, during which 82 premenopausal and 200 postmenopausal women reported CVD incidence. The highest tofu, total soy foods, and dietary soy isoflavone intake groups were significantly associated with a decreased CVD risk in premenopausal women (tofu: hazard ratio (HR) 0.39; 95% confidence interval (CI), 0.19–0.80; total soy food: HR 0.36; 95% CI, 0.18–0.70; dietary soy isoflavones: HR 0.44; 95% CI, 0.22–0.89), whereas no association was observed in postmenopausal women. Other soy foods showed no association with CVD incidence. Dietary soy isoflavones and total soy foods are associated with a decreased CVD risk in premenopausal women. Among soy foods, only tofu showed significant health benefits.

Utilization of Isoflavones in Soybeans for Women with Menopausal Syndrome: An Overview.

Based on their nutrient composition, soybeans and related foods have been considered to be nutritious and healthy for humans. Particularly, the biological activity and subsequent benefits of soy products may be associated with the presence of isoflavone in soybeans. As an alternative treatment for menopause-related symptoms, isoflavone has gained much popularity for postmenopausal women who have concerns related to undergoing hormone replacement therapy. However, current research has still not reached a consensus on the effects of isoflavone on humans. This overview is a summary of the current literature about the processing of soybeans and isoflavone types (daidzein, genistein, and S-equol) and supplements and their extraction and analysis as well as information about the utilization of isoflavones in soybeans. The processes of preparation (cleaning, drying, crushing and dehulling) and extraction of soybeans are implemented to produce refined soy oil, soy lecithin, free fatty acids, glycerol and soybean meal. The remaining components consist of inorganic constituents (minerals) and the minor components of biologically interesting small molecules. Regarding the preventive effects on diseases or cancers, a higher intake of isoflavones is associated with a moderately lower risk of developing coronary heart disease. It may also reduce the risks of breast and colorectal cancer as well as the incidence of breast cancer recurrence. Consumption of isoflavones or soy foods is associated with reduced risks of endometrial and bladder cancer. Regarding the therapeutic effects on menopausal syndrome or other diseases, isoflavones have been found to alleviate vasomotor syndromes even after considering placebo effects, reduce bone loss in the spine and ameliorate hypertension and in vitro glycemic control. They may also alleviate depressive symptoms during pregnancy. On the other hand, isoflavones have not shown definitive effects regarding improving cognition and urogenital symptoms. Because of lacking standardization in the study designs, such as the ingredients and doses of isoflavones and the durations and outcomes of trials, it currently remains difficult to draw overall conclusions for all aspects of isoflavones. These limitations warrant further investigations of isoflavone use for women’s health.

Fermented Soy Products: Beneficial Potential in Neurodegenerative Diseases

Fermented soybean products, such as cheonggukjang (Japanese natto), doenjang (soy paste), ganjang (soy sauce), and douchi, are widely consumed in East Asian countries and are major sources of bioactive compounds. The fermentation of cooked soybean with bacteria (Bacillus spp.) and fungi (Aspergillus spp. and Rhizopus spp.) produces a variety of novel compounds, most of which possess health benefits. This review is focused on the preventive and ameliorative potential of fermented soy foods and their components to manage neurodegenerative diseases, including Alzheimer’s and Parkinson’s diseases.

Assessment of the Physicochemical and Conformational Changes of Ultrasound-Driven Proteins Extracted from Soybean Okara Byproduct.

This study was aimed at the valorization of the okara byproduct deriving form soy food manufacturing, by using ultrasound at different temperatures for extracting the residual proteins. The physicochemical and conformational changes of the extracted proteins were investigated in order to optimize the procedure. Increasing the temperature from 20 up to 80 °C greatly enhanced the yields and the protein solubility without affecting the viscosity. The protein secondary and tertiary structures were also gradually modified in a significant way. After the ultrasonication at the highest temperature, a significant morphological transition from well-defined single round structures to highly aggregated ones was observed, which was confirmed by measuring the water contact angles and wettability. After the ultrasound process, the improvement of peptides generation and the different amino acid exposition within the protein led to an increase of the antioxidant properties. The integrated strategy applied in this study allows to foster the okara protein obtained after ultrasound extraction as valuable materials for new applications.

Impact of Lactobacillus cultures on production of B-vitamins, organic acids and biotransformation of soy isoflavones

AbstractIn the study, four potent Lactobacillus cultures of L. rhamnosus K4E, L. plantarum RD7, L. fermentum K7, and L. fermentum K16 were considered for the production of B-vitamins, organic acids and biotransformation of soy isoflavones. L. plantarum RD7 showed the highest B2 production (0.84 μg mL−1) after 36 h, while L. fermentum K16 exhibited maximum B12 production (0.084 μg mL−1) after 12 h. L. rhamnosus K4E produced 0.24 μg mL−1 of folate after 12 h. Highest production of lactate (16.43 μg mL−1) and acetate (5.86 μg mL−1) was reported by L. rhamnosus K4E. L. plantarum RD7 showed maximum butyrate (0.253 μg mL−1) production compared to the other cultures. The highest bioconversion of soy aglycones was reported by L. rhamnosus K4E with 55.43% for daidzein and 72.30% for genistein, during soymilk fermentation. These potent cultures have a potential to be used as functional starter cultures for the production of functional fermented soy foods.

Synthesis and structural elucidation of a series of isoflavones-based on FPR antagonists

Synthesis and structural elucidation of a series of isoflavones-based on FPR antagonists

A Non-Probiotic Fermented Soy Product Reduces Total and LDL Cholesterol: A Randomized Controlled Crossover Trial.

Traditional Asian fermented soy food products are associated with reduced cardiovascular disease risk in prospective studies, but few randomized controlled trials have been conducted in at-risk populations. The aim of this study was to investigate the effect of a commercial non-probiotic fermented soy product on blood lipids in adults with cardiovascular risk biomarkers. In a randomized, crossover, intervention study, 27 men and women (aged 29–75 y) exhibiting at least two risk factors, consumed two packets (12.5 g each) daily of a fermented powdered soy product, or an isoenergic control powder made from germinated brown rice for 12 weeks each. The consumption of the fermented soy product resulted in a significantly greater mean change from baseline (compared to the germinated rice, all p < 0.05) in total cholesterol of −0.23 mmol/L (CI: −0.40, −0.06) compared with 0.14 mmol/L (CI: −0.03, 0.31), respectively; and low density lipoprotein (LDL) cholesterol −0.18 mmol/L (CI: −0.32, −0.04) compared with 0.04 mmol/L (CI: −0.01, 0.018) respectively. This was accompanied by an increase in high density lipoprotein (HDL) cholesterol in the germinated rice group, a decrease in apolipoprotein B (ApoB) in the fermented soy group, and a between-treatment effect in apolipoprotein A1 (ApoA1); however, the ratio of the LDL:HDL and of Apo B:ApoA1 did not differ between the groups. The ratio of total cholesterol:LDL decreased in men in the fermented soy group (p < 0.001). Twenty-four-hour urine collection at the end of each treatment period resulted in an increased excretion expressed as a ratio in μmol/d between treatments of 10.93 (CI: 5.07, 23.54) for daidzein; 1.24 (CI: 1.14, 4.43) for genistein; and, 8.48 (CI: 4.28, 16.80) for glycitein, all p < 0.05. The fermented soy powder consumed by participants in this study without implementing other changes in their typical diets, decreased the total and LDL cholesterol, and may serve as a dietary strategy to manage blood lipids. The trial was registered at ClinicalTrials.gov as NCT03429920.

γ-PGA-Rich Chungkookjang, Short-Term Fermented Soybeans: Prevents Memory Impairment by Modulating Brain Insulin Sensitivity, Neuro-Inflammation, and the Gut-Microbiome-Brain Axis.

Fermented soybean paste is an indigenous food for use in cooking in East and Southeast Asia. Korea developed and used its traditional fermented foods two thousand years ago. Chungkookjang has unique characteristics such as short-term fermentation (24–72 h) without salt, and fermentation mostly with Bacilli. Traditionally fermented chungkookjang (TFC) is whole cooked soybeans that are fermented predominantly by Bacillus species. However, Bacillus species are different in the environment according to the regions and seasons due to the specific bacteria. Bacillus species differently contribute to the bioactive components of chungkookjang, resulting in different functionalities. In this review, we evaluated the production process of poly-γ-glutamic acid (γ-PGA)-rich chungkookjang fermented with specific Bacillus species and their effects on memory function through the modulation of brain insulin resistance, neuroinflammation, and the gut–microbiome–brain axis. Bacillus species were isolated from the TFC made in Sunchang, Korea, and they included Bacillus (B.) subtilis, B. licheniformis, and B. amyloliquefaciens. Chungkookjang contains isoflavone aglycans, peptides, dietary fiber, γ-PGA, and Bacillus species. Chungkookjangs made with B. licheniformis and B. amyloliquefaciens have higher contents of γ-PGA, and they are more effective for improving glucose metabolism and memory function. Chungkookjang has better efficacy for reducing inflammation and oxidative stress than other fermented soy foods. Insulin sensitivity is improved, not only in systemic organs such as the liver and adipose tissues, but also in the brain. Chungkookjang intake prevents and alleviates memory impairment induced by Alzheimer’s disease and cerebral ischemia. This review suggests that the intake of chungkookjang (20–30 g/day) rich in γ-PGA acts as a synbiotic in humans and promotes memory function by suppressing brain insulin resistance and neuroinflammation and by modulating the gut–microbiome–brain axis.

An high-throughput sequencing approach to the preliminary analysis of bacterial communities associated with changes in amino acid nitrogen, organic acid and reducing sugar contents during soy sauce fermentation

Soy sauce is a traditional fermented soy food for enhancing the umami taste in Asian cuisines. In this study, 16S rRNA gene throughput sequencing analysis showed the bacterial communities and the changes in soy sauce during fermentation. Weissella, Bacillus and Lactococcus were the most abundant at genus level. The uncultured bacterium Weissella and Lactococcus had relatively high abundance at species level. Alpha diversity analysis indicated the bacterial community diversity increased at fermentation initiation, while decreased as fermentation progressed. Based on beta-diversity analysis, four clusters including cluster I (time point A-F), cluster II (G,H), cluster III (I,J) and cluster IV(K) were distinctly separated, indicating the fermentation time significantly affected bacterial community diversity. Also, close associations were found between the bacterial communities in soy sauce and its amino acid nitrogen, organic acid and reducing sugar contents during fermentation. Therefore, it will provide important information for optimization of the soy sauce production process.

Linkage and association study discovered loci and candidate genes for glycinin and β-conglycinin in soybean (Glycine max L. Merr.).

Linkage mapping and GWAS identified 67 QTLs related to soybean glycinin, β-conglycinin and relevant traits. Polymorphisms of the candidate gene Gy1 promoter were associated with the glycinin content in soybean. The major components of storage proteins in soybean seeds are glycinin and β-conglycinin, which play important roles in determining protein nutrition and soy food processing properties. Increasing the protein content while improving the ratio of glycinin to β-conglycinin is substantially important for soybean protein improvement. To investigate the genetic mechanism of storage protein subunits, 184 recombinant inbred lines (RILs) derived from a cross of Kefeng No. 1 and Nannong 1138-2 and 211 diverse soybean cultivars were used to detect loci related to glycinin (11S), β-conglycinin (7S), the sum of glycinin and β-conglycinin (SGC), and the ratio of glycinin to β-conglycinin (RGC). Sixty-seven QTLs and 11 hot genomic regions were identified as affecting the four traits. One genetic region (q10-1) on chromosome 10 was associated with multiple traits by both linkage and association analysis. Eight genes in 11 hot genomic regions might be related to soybean protein subunit. The candidate gene analysis showed that polymorphisms in Gy1 promoters were significantly correlated with the 11S content. The QTLs and candidate genes identified in the present study allow for further understanding the genetic basis of 11S and 7S regulation and provide useful information for marker-assisted selection (MAS) in soybean quality improvement.