Soy Foods Research Articles

Association of Soy Foods With Gastric Cancer Considering Helicobacter pylori: A Multi-Center Case-Control Study.

This study aims to explore the relationship between soy food consumption and gastric cancer (GC) risk, accounting for Helicobacter pylori infection status. We analyzed data from patients with GC and healthy individuals prospectively enrolled by 6 hospitals between 2016 and 2018. Dietary intake was evaluated using questionnaires that categorized seven dietary habits and 19 food groups. Multivariate logistic regression models were applied to examine associations. Model I adjusted for various epidemiological factors, while Model II included further adjustments for H. pylori infection. Primary exposures examined were consumption frequencies of nonfermented, unsalted soy foods (soybean/tofu) and fermented, salty soy foods (soybean paste stew). A total of 5,535 participants were included, with 1,629 diagnosed with GC. In Model I, the frequency of soybean/tofu consumption was inversely related to GC risk; adjusted odd ratios (aORs) were 0.62 (95% confidence interval [CI], 0.48-0.8), 0.38 (95% CI, 0.3-0.49), 0.42 (95% CI, 0.33-0.53), and 0.33 (95% CI, 0.27-0.42) for 1 time/week, 2 times/week, 3 times/week, and ≥4 times/week. Consumption of 2 servings/week of soybean paste stew showed the lowest GC association, forming a V-shaped curve. Both low (aOR, 4.03; 95% CI, 3.09-5.26) and high serving frequencies of soybean paste stew (aOR, 2.23; 95% CI, 1.76-2.82) were associated with GC. The association between soy foods and GC in Model II was similar to that in Model I. The soy food-GC associations were consistent across sexes in Model I. Nonetheless, the positive correlation between frequent consumption of soybean paste stew (≥5 times/week) and GC was more pronounced in women (aOR, 7.58; 95% CI, 3.20-17.99) compared to men (aOR, 3.03; 95% CI, 1.61-5.88) in Model II. Subgroup analyses by H. pylori status and salty diet revealed a consistent inverse relationship between soybean/tofu and GC risk. In contrast, soybean paste stew showed a V-shaped relationship in H. pylori-positive or salty diet groups and no significant association in the H. pylori-negative group. Soybean/tofu intake is consistently associated with a decreased risk of GC. However, the relationship between soybean paste stew consumption and GC risk varies, depending on H. pylori infection status and dietary salt intake. ClinicalTrials.gov Identifier: NCT03046745.

TEMPORARY REMOVAL: Effect of soy isoflavones on measures of estrogenicity: A systematic review and meta-analysis of randomized controlled trials

BackgroundDespite recommendations to increase plant food consumption for public and planetary health and the role that soy foods can play in plant-predominant diets, controversies around the effects of soy foods and especially soy isoflavones, are a barrier to their intake. Given their cardioprotective effects and ability to alleviate menopausal symptoms, addressing these concerns is particularly relevant to women. ObjectiveThis systematic review and meta-analysis of randomized controlled trials aimed to determine the effect of soy isoflavones on measures of estrogenicity in postmenopausal women. MethodsMEDLINE, Embase, and Cochrane Library were searched through August 2024 for randomized trials 3-months investigating soy isoflavones versus non-isoflavone controls in postmenopausal women. Outcomes included endometrial thickness (ET), vaginal maturation index (VMI), follicle-stimulating hormone (FSH), and estradiol. Independent authors extracted data and assessed risk of bias. GRADE (grading of recommendations assessment, development, and evaluation) was used to assess certainty of evidence. ResultsWe included 40 trials (52 trial comparisons, n=3285) assessing the effect of a median reported dose of 75mg/day of soy isoflavones in substitution for non-isoflavone controls over a median of 24 weeks. Soy isoflavones had no statistically significant effect on any measure of estrogenicity; ET (mean difference, -0.22mm [95% confidence interval, -0.45, 0.01mm], PMD=0.059), VMI (2.31 [-2.14, 6.75], PMD=0.310), FSH (-0.02IU/L [-2.39, 2.35IU/L], PMD=0.987), and estradiol (1.61pmol/L [-1.17, 4.38pmol/L], PMD=0.256). The certainty of evidence was high-to-moderate for all outcomes. ConclusionsCurrent evidence suggests that soy isoflavones do not exhibit estrogenic effects compared to non-isoflavone controls on 4 measures of estrogenicity in postmenopausal women. This synthesis supports that soy isoflavones likely act as selective estrogen receptor modulators, differing clinically from the hormone estrogen. Addressing public health concerns may promote soy foods as high-quality plant protein sources with low environmental impact and cost, particularly benefiting postmenopausal women, and aligning with sustainable dietary patterns and guidelines. RegistrationPROSPERO (CRD42023439239)

Mechanism governing textural changes of low-moisture tofu induced by NaCl addition in soymilk

This study aimed to investigate the impact of NaCl (0 – 1 g/100 mL) on the textural properties of calcium-coagulated low-moisture tofu (LM-tofu) and explore the underlying mechanism governing the NaCl-induced changes of relevant properties. Increasing the NaCl level in soymilk led to higher yield (134.2 – 192.2 g/100 g soybean) of LM-tofu with higher water content (69.2 – 76.7%), reduced protein (11.3 – 16.3%) and lipid (6.87 – 9.22%) levels, and enhanced water binding capacity (WBC, 4.26 – 6.78 g H2O/g protein) and water holding capacity (WHC, 3.63 – 5.49 g H2O/g protein) of soy proteins. Although NaCl had a minor effect on the interactions between proteins and mobilized water or tightly bound water, it significantly improved the proteins' ability to bind loosely bound water due to electrostatic interactions between the charged groups of proteins and hydrated Cl- and Na+ ions. Moreover, the amounts of loosely bound water were highly correlated with both WBC and WHC of proteins (correlation coefficient: 0.999 and 0.995, respectively). The enhanced water binding capacity of proteins for loosely bound water due to an increased salt level resulted in LM-tofu with a less dense protein network structure, weaker strength and reduced deformation ability. This study provides insights for the development of high-calcium, soy protein-based foods to meet the growing demands for healthy and convenient plant-based snacks or meals.

Proteomic Analysis of the Characteristic Flavor Components in Bacillus subtilis BSNK-5-Fermented Soymilk.

Fermentation with Bacillus subtilis significantly enhances the physiological activity and bioavailability of soymilk, but the resulting characteristic flavor seriously affects its industrial promotion. The objective of this study was to identify key proteins associated with characteristic flavors in B. subtilis BSNK-5-fermented soymilk using tandem mass tag (TMT) proteomics. The results showed that a total of 765 differentially expressed proteins were identified. Seventy differentially expressed proteins related to characteristic flavor were screened through Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis. After integrating metabolomics data, fifteen key proteases of characteristic flavor components in BSNK-5-fermented soymilk were further identified, and free ammonia was added. In addition, there were five main formation mechanisms, including the decomposition of urea to produce ammonia; the degradation of glutamate by glutamate dehydrogenase to produce ammonia; the degradation of threonine and non-enzymatic changes to form the derivative 2,5-dimethylpyrazine; the degradation of valine, leucine, and isoleucine to synthesize isovalerate and 2-methylbutyrate; and the metabolism of pyruvate and lactate to synthesize acetate. These results provide a theoretical foundation for the improvement of undesirable flavor in B. subtilis BSNK-5-fermented soy foods.

Dietary and circulating branched chain amino acids are unfavorably associated with body fat measures among Chinese adults

Animal studies showed a detrimental effect of dietary branched chain amino acids (BCAAs) on metabolic health, while epidemiological evidence on dietary BCAAs and obesity is limited and inconclusive. We hypothesized that high dietary and circulating BCAAs are unfavorably associated with obesity in community-dwelling adults. We evaluated the 1-year longitudinal associations of dietary BCAA intake and circulating BCAAs with body fat measures. Body weight, height, and circumferences of the waist (WC) and hip (HC) were measured at baseline and again after 1-year. Body composition and liver fat [indicated by controlled attenuation parameter (CAP)] were also assessed after 1-year. Serum BCAA concentrations at baseline were quantified by liquid chromatography mass spectrometry. Diet was collected using 4 quarterly 3-day recalls during the 1-year. The correlation coefficients between dietary and serum BCAAs were 0.12 (P = .035) for total dietary BCAAs, and ranged from -0.02 (soy foods, P = .749) to 0.18 (poultry, P = .001). Total dietary BCAA intake was associated with increase in body weight (β = 0.044, P = .022) and body mass index (BMI, β = 0.047, P = .043). BCAAs from animal foods were associated with increase in HC, while BCAAs from soy foods were associated with weight gain and higher CAP (all P < .05). Serum BCAAs were associated with higher WC, HC, BMI, body fat mass, visceral fat level, and CAP (all P < .05). These results support that dietary and circulating BCAAs are positively associated with the risk of obesity. More cohort studies with validated dietary assessment tools and long-term follow-up among diverse populations are needed to confirm our findings.

Effects of Salinity on Physicochemical Properties, Flavor Compounds, and Bacterial Communities in Broad Bean Paste-Meju Fermentation.

Broad bean paste (BBP) is a traditional fermented soy food, and its high salt content not only prolongs the fermentation time but also threatens human health. In this study, three BBP-meju with different salt concentrations were prepared, and the effects of varying salinity on fermentation were comprehensively compared. The results showed that salt-reduced fermentation contributed to the accumulation of amino acid nitrogen, reducing sugars, free amino acids, and organic acids. Alcohols, esters, aldehydes, and acids were the main volatile flavor compounds in BBP-meju, and the highest total volatile flavor compounds were found in medium-salt meju. Bacillus, Staphylococcus, Aspergillus, and Mortierella were the dominant microbial communities during fermentation, and there were also three opportunistic pathogens, Enterobacter, Pantoea, and Brevundimonas, respectively. According to Spearman correlation analysis, Wickerhamomyces, Bacillus, Staphylococcus, and Mortierella all showed highly significant positive correlations with ≥3 key flavor compounds, which may be the core functional flora. Furthermore, the dominant microbial genera worked synergistically to promote the formation of high-quality flavor compounds and inhibit the production of off-flavors during salt-reduced fermentation. This study provides a theoretical reference for the quality and safety control of low-salt fermented soy foods.

Recommended Diet Therapy of Mediterranean Diet (MD) and Low Carbohydrate Diet (LCD)

To maintain health and achieve longevity, an adequate diet is crucial, such as the Mediterranean diet (MD) and the low-carbohydrate diet (LCD). The MD is characterized by whole grains, fruits, vegetables, less red meat, more fish, and four eggs per week. The MD may reduce the risk of heart disease, stroke, dementia, and depression. The LCD shows remarkable weight reduction in a short period, but there may be a probable rebound effect within six months. In Japanese cuisine, the intake of fermented soy foods such as natto and miso can lower the risk of death. As a recommendation, the LCD can be started first, followed by the MD for the long term.

Soy Foods Consumption and Lipid Abnormalities in Korean Adults: Results From the KoGES-HEXA Study

Soy Foods Consumption and Lipid Abnormalities in Korean Adults: Results From the KoGES-HEXA Study

Effects of Soy Foods on Childhood Physical and Cognitive Health: The Plants Optimizing Development Study (PODS) Protocol

Effects of Soy Foods on Childhood Physical and Cognitive Health: The Plants Optimizing Development Study (PODS) Protocol

Antibiofilm activity of d-limonene against spoilage Bacillus amyloliquefaciens

This study aimed to determine the efficacy of d-limonene in preventing biofilm formation by Bacillus amyloliquefaciens, a soy food spoilage bacterium. The minimal biofilm inhibitory concentrations (MBICs) of d-limonene against two strains of B. amyloliquefaciens were determined using a twofold dilution method. Furthermore, the ability of d-limonene to eradicate preformed biofilms was evaluated using the TTC reduction method. Subsequent analyses investigated the effects of d-limonene on biofilm morphology, cell motility, cell surface characteristics, and the composition of the biofilm matrix. The MBICs of d-limonene for B. amyloliquefaciens strains DY1a and DY1b were determined to be 24 and 36 μL/mL, respectively. At 2 MBIC, d-limonene eradicated 63.67% of the DY1a biofilms and 52.63% of the DY1b biofilms. Significantly, d-limonene markedly reduced swimming and swarming motility at concentrations ranging from 1/2 to 1 MBIC. In particular, at 1/2 MBIC, d-limonene decreased swimming and swarming abilities by 85.88% and 37.84%, respectively, for strain DY1a and by 75.00% and 95.07%, respectively, for strain DY1b. Furthermore, d-limonene suppressed the biosynthesis of polysaccharides and proteins in the extracellular biofilm matrix and reduced cell surface hydrophobicity, surface charge, and autoaggregation. These findings suggest that d-limonene could be an effective antibiofilm agent for the control of B. amyloliquefaciens in the soybean food industry.

Consumption of soya isoflavones improved polycystic ovary syndrome-associated metabolic disorders in a rat model.

Polycystic ovary syndrome is associated with increased risks for certain metabolic disorders such as insulin resistance, non-alcoholic fatty liver disease and suppressed ovarian follicular development. This study aimed to examine whether soya isoflavones (ISF) mitigate these polycystic ovary syndrome-associated metabolic disorders in a rat model. Weanling Sprague-Dawley female rats were randomly divided into six groups and were treated with either 0 or 83 µg/d dihydrotestosterone (DHT) to induce polycystic ovary syndrome and fed diets containing 0, 0·5, or 1 g ISF/kg diet for 8 weeks. DHT treatment increased food intake, body weight gain (P < 0·001), percentage of primordial follicles (60 % v. 50·9 %, P < 0·05) and accumulation of lipid droplets in the livers. It also elevated serum total cholesterol, free cholesterol, TAG, NEFA and leptin and hepatic total cholesterol and NEFA. Additionally, DHT treatment reduced the percentage of primary follicles (13·8 % v. 30·2 %, P < 0·05), ovary weight and length (P < 0·001), as well as insulin sensitivity (P < 0·01) compared with the Control. ISF intake at 1 g/kg reduced body weight gain, serum total cholesterol, free cholesterol, NEFA, leptin and hepatic TAG and DHT-induced insulin resistance (P < 0·01). ISF intake at both levels decreased DHT-induced lipid droplet accumulation in the livers and changes in the percentages of primordial and primary follicles. Dietary soya ISF alleviated DHT-induced body weight gain, insulin resistance and hepatic lipid droplet accumulation, as well as suppressed ovarian follicular development. This suggests that the consumption of soya foods or ISF supplements may be beneficial for individuals with polycystic ovary syndrome, mitigating the associated metabolic disorders such as diabetes and non-alcoholic fatty liver disease.

Daidzein and Equol: Ex Vivo and In Silico Approaches Targeting COX-2, iNOS, and the Canonical Inflammasome Signaling Pathway.

The inflammasome is a cytosolic multiprotein complex associated with multiple autoimmune diseases. Phytochemical compounds in soy (Glycine max) foods, such as isoflavones, have been reported for their anti-inflammatory properties. the anti-inflammatory activity of DZ (daidzein) and EQ (equol) were investigated in an ex vivo model of LPS-stimulated murine peritoneal macrophages and by molecular docking correlation. Cells were pre-treated with DZ (25, 50, and 100 µM) or EQ (5, 10, and 25 µM), followed by LPS stimulation. The levels of PGE2, NO, TNF-α, IL-6, and IL-1β were analyzed by ELISA, whereas the expressions of COX-2, iNOS, NLRP3, ASC, caspase 1, and IL-18 were measured by Western blotting. Also, the potential for transcriptional modulation by targeting NF-κB, COX-2, iNOS, NLRP3, ASC, and caspase 1 was investigated by molecular docking. The anti-inflammatory responses observed may be due to the modulation of NF-κB due to the binding of DZ or EQ, which is translated into decreased TNF-α, COX-2, iNOS, NLRP3, and ASC levels. This study establishes that DZ and EQ inhibit LPS-induced inflammatory responses in peritoneal murine macrophages via down-regulation of NO and PGE2 generation, as well as the inhibition of the canonical inflammasome pathway, regulating NLRP3, and consequently decreasing IL-1β and IL-18 activation.

Traditional and Domestic Cooking Dramatically Reduce Estrogenic Isoflavones in Soy Foods.

Soybean is a pulse which has considerable nutritional value due to its high protein, fibers and polyunsaturated fatty acid (PUFA) contents. It also contains phytoestrogenic compounds that definitely hinder its recommendation for general consumption. Contrary to ancient times, when soybeans were boiled, modern commercial soy foods can contain up to 150 mg/100g of estrogenic isoflavones. Interestingly, current estimations of isoflavone intake in the literature do not distinguish between the origins of soy food, i.e., whether it is homemade or commercial. As a result, the isoflavone exposure in Asian countries may well be overestimated. This study aims to demonstrate, based on step-by-step monitoring of isoflavones, that traditional and domestic treatments, leveraging isoflavones water-solubility, can indeed significantly reduce their content in soy foods. Indeed, when compared to commercial foods, the isoflavone content was found to be 20, 2.6, 4.5 and 9.8 times lower in "homemade" soy juice, tofu, tempeh and miso, respectively. Additionally, water soaking was found to reduce the isoflavones levels in soy-textured proteins by more than 70%. Hence, this simple process has the potential to help drastically reduce overall xenoestrogens exposure. This study could serve as a basis for establishing the isoflavones Reference Dose and issuing food safety guidelines.

Screening and Optimization of α-Glucosidase Inhibitor Production by Potent Strain of Bacillus subtilis Isolated from Peruyaan, Fermented Soy-Food of Northeast India

Background. Fermented soy foods exhibit the capability to inhibit the α-glucosidase enzyme. The bacteria isolated from these fermented soy foods may contribute to the production of a higher quantity of α-glucosidase inhibitor (α-GI) in optimized condition. Aim. The present study aims to isolate α-glucosidase inhibitor producing bacterial strain from peruyaan, a traditional fermented soy food of Arunachal Pradesh, optimize the production of α-GI for maximum yield, and assess the compounds. Result. Bacillus subtilis PM NEIST_4 (identified by 16S rRNA gene sequencing) was isolated as a potential strain that exhibit maximum α-glucosidase inhibition. This strain showed maximum α-GI productivity in Mueller Hinton Broth (MHB). The cultivation parameters for fermentation of MHB were optimized in order to maximize the yield of α-GIs. The α-GI productivity of 1616.613 ± 84.54 U/mL was observed before optimization, which increased by almost three times after optimization (4808.324 ± 13 U/mL). In vitro assays against α-glucosidase enzyme revealed a significant IC50 value of 596.532 ± 44.80 μg/mL after the optimized study compared to that before optimization (IC50 1705.617 ± 43.95 ug/mL). Besides, α-glucosidase enzyme inhibitory property of fermented MHB (FMHB) was found to be unaffected at varied range of pH and temperature. Oral gavaging of FMHB in sucrose-loaded Wistar rat exhibited maximum reduction in postprandial blood glucose at 400 mg/kg body weight. Furthermore, FMHB was fractionated using solvents of increasing polarity including n-hexane, ethyl acetate, and n-butanol. Ethyl acetate fraction that exhibited the strongest inhibitory action against the α-glucosidase enzyme (IC50 value of 251.55 ± 19.65 μg/mL), showed the presence of pyrrolopyrazine derivatives through GC-MS and LC-MS analyses. Conclusion. The present study demonstrated the isolation of a potent α-GI producing bacterial strain from traditional fermented soy food, and the optimization of the bacterial fermentation process was achieved to maximize the yield of α-GI. These findings underscore promising industrial potential of B. subtilis PM NEIST_4, advocating the use of indigenous microbial resources for the production of α-GI.

Perspective: Observational Studies Involving Low-Soy Intake Populations Have Limited Ability for Providing Insight into the Health Effects of Soybean Isoflavones

Isoflavones are naturally occurring plant compounds found in uniquely high amounts in soybeans and foods made from this legume. These soybean constituents have been proposed to exert several health benefits and as such they have been the subject of an enormous amount of research. This research includes randomized controlled trials (RCTs) and epidemiologic investigations. Although statistically significant associations between isoflavone intake and a wide range of health outcomes have been identified in cohorts involving low-isoflavone intake populations, we suggest that these associations are unlikely to have a causal basis because exposure is too low for isoflavones to exert physiologic effects. In cohorts involving predominantly non-Asian, non-vegetarian populations, the highest isoflavone intake category is typically ≤3 mg/d, an amount of isoflavones provided by ∼30 mL (2 tablespoons) of soymilk made from whole soybeans. In comparison, mean isoflavone intake in the upper intake categories in observational studies involving high-isoflavone intake populations is typically ≥50 mg/d. In RCTs, intervention doses of isoflavones typically range between 40 and 100 mg/d. Health professionals advising patients and clients about soy food and isoflavone intake need to be aware of the limitations of epidemiologic research involving low-isoflavone intake populations. Intake recommendations are best based on the results of RCTs using clinically relevant doses of isoflavones and epidemiologic studies involving populations for whom soy foods are a habitual part of the diet.

Identification of Quantitative Trait Loci (QTL) for Sucrose and Protein Content in Soybean Seed.

Protein and sugar content are important seed quality traits in soybean because they improve the value and sustainability of soy food and feed products. Thus, identifying Quantitative Trait Loci (QTL) for soybean seed protein and sugar content can benefit plant breeders and the soybean market by accelerating the breeding process via marker-assisted selection. For this study, a population of recombinant inbred lines (RILs) was developed from a cross between R08-3221 (high protein and low sucrose) and R07-2000 (high sucrose and low protein). Phenotypic data for protein content were taken from the F2:4 and F2:5 generations. The DA7250 NIR analyzer and HPLC instruments were used to analyze total seed protein and sucrose content. Genotypic data were generated using analysis via the SoySNP6k chip. A total of four QTLs were identified in this study. Two QTLs for protein content were located on chromosomes 11 and 20, and two QTLs associated with sucrose content were located on chromosomes 14 and. 11, the latter of which co-localized with detected QTLs for protein, explaining 10% of the phenotypic variation for protein and sucrose content in soybean seed within the study population. Soybean breeding programs can use the results to improve soybean seed quality.

A Systematic Comparative Study on the Physicochemical Properties, Volatile Compounds, and Biological Activity of Typical Fermented Soy Foods

Fermented soy foods can effectively improve the unpleasant odor of soybean and reduce its anti-nutritional factors while forming aromatic and bioactive compounds. However, a differential analysis of characteristic flavor and function among different fermented soy foods has yet to be conducted. In this study, a systematic comparison of different fermented soy foods was performed using E-nose, HS-SMPE-GC×GC-MS, bioactivity validation, and correlation analysis. The results showed that soy sauce and natto flavor profiles significantly differed from other products. Esters and alcohols were the main volatile substances in furu, broad bean paste, douchi, doujiang, and soy sauce, while pyrazine substances were mainly present in natto. Phenylacetaldehyde contributed to the sweet aroma of furu, while 1-octene-3-ol played a crucial role in the flavor formation of broad bean paste. 2,3-Butanediol and ethyl phenylacetate contributed fruity and honey-like aromas to douchi, doujiang, and soy sauce, respectively, while benzaldehyde played a vital role in the flavor synthesis of douchi. All six fermented soy foods demonstrated favorable antioxidative and antibacterial activities, although their efficacy varied significantly. This study lays the foundation for elucidating the mechanisms of flavor and functionality formation in fermented soy foods, which will help in the targeted development and optimization of these products.

Mental health and diet quality after primary treatment for ovarian cancer.

To investigate anxiety and depression after primary treatment for ovarian cancer in relation to diet quality and intake. In a cohort of women with ovarian cancer in Australia, levels of anxiety and depression (normal, subclinical, and clinical) were assessed using the Hospital Anxiety and Depression Scale at 9 months post-diagnosis. Dietary intake was assessed using a validated food frequency questionnaire at 12 months post-diagnosis and scored using the Healthy Eating Index 2015. Multinomial logistic regression and bivariate analyses were used to investigate relationships between levels of anxiety and depression and subsequent diet quality and intake of food groups. Of 595 women, anxiety and depression were identified among 128 (21%) and 80 (13%) women, respectively. Compared to women without anxiety or depression, women with subclinical anxiety (odds ratio = 0.49, 95% confidence interval: 0.25-0.98) and those with clinical depression (odds ratio = 0.25, 95% confidence interval: 0.07-0.93) were less likely to score in the highest quartile for diet quality. Separate adjustment for age, education, employment, disease stage, body mass index, and smoking status did not attenuate these associations. In bivariate analyses, women with subclinical anxiety were more likely to report higher intakes of sweet foods. Those with clinical depression were more likely to report lower intakes of orange vegetables and wholegrains, higher intakes of sweetened beverages, and not consume alcohol or soya foods. Anxiety or depression after primary treatment for ovarian cancer may be associated with poorer diet quality. Efforts to improve diet quality post-treatment should consider support for mental health.

In vitro DIAAS of Swiss soybean cultivars using the INFOGEST model: Increase in protein quality from soybean to soymilk and tofu

To support the transition towards more sustainable and healthy diets, viable alternatives to foods of animal origin need to be identified. Many plant-based protein sources are currently marketed with claims of minimal environmental impact, but very limited consideration has been given to their protein quality and bioavailable mineral content considering the fact that animal-based foods are typically the primary source of both in Western diets. In this study, traditionally consumed soy foods (cooked soybeans, soymilk, tofu) from different Swiss soybean cultivars were nutritionally characterized and the in vitro digestibility of individual amino acids and total protein were assessed using an in vitro model based on the static INFOGEST protocol; the protein quality was evaluated using the in vitro digestible indispensable amino acid score (DIAAS). The results reveal an increase in total protein in vitro digestibility across the traditional soy food production value chain: 52.1–62.7% for cooked soybeans, 84.1–90.6% for soymilk, and 94.9–98.4% for tofu. Protein quality, determined using the recommended amino acid pattern for 0.5–3 years old, was “low” (no claim) for cooked soybeans (DIAAS < 60), while soymilk (DIAAS = 78–88) and tofu products (DIAAS = 79–91) were of similar “good” protein quality, with considerably higher DIAAS values than those of cooked soybeans (P < 0.001). The iron and zinc contents in soy foods were substantial, but high molar ratios of phytic acid (PA) to iron (PA/Fe; >8) and PA to zinc (PA/Zn; >15) indicate a possible strong inhibition of iron and zinc bioavailability. Based on the DIAAS results, soymilk and tofu would be suitable plant-based alternatives to animal-based foods, while future efforts should focus on optimizing soybean preparation to overcome the negative effects of the plant tissue matrix as well as processing steps to reduce mineral absorption inhibiting substances.

Developing a machine for peeling, fracturing, and separating dry soybean skins with electric blower technology to boost the production of soy-based materials

Soybean is a commodity that plays an important role in the sustainable food and agriculture sector. As a result, various businesses are involved in the processing of soy foods. The problem in the soybean processing business is that the process of peeling, cracking, and separating the soybean epidermis is usually done by hand or using a simple machine. The aim of this study was to develop a machine for peeling, breaking and separating dry soybean husk based on electric blower technology and having the following specifications: (a) dimensions 850 x 700 x 1200 mm; (b) production capacity of 250 kg/hour; (c) roller wheel clearance mechanism; (d) the mechanism for removing raw materials from the grinding chamber; (5) The separating mechanism in the Formula is used to calculate the capacity of the testing machine, the success rate of stripping, and the efficiency of testing the epidermis with a blower. The findings obtained in the evaluation of the performance production capacity of the machine with an average yield of 213.048 kg/hour and testing the efficiency of the blower on the epidermis got an average value of 83.84% and testing the success rate of stripping using a machine got an average value of 74.03%.