Traditional Soybean Research Articles

Reduction of aflatoxins and ochratoxin A by addition of commercial Koji during fermentation of the Korean traditional soybean paste, Doenjang

Contamination by aflatoxins and ochratoxin A of traditional Korean fermented soybean paste (Doenjang) is a serious food safety issue. In this study, we investigated the inhibitory effects of commercial Koji, a microbial starter culture used for fermentation, on mycotoxin contamination during Doenjang production at in vitro and scaled-up fermentation levels. A commercial Koji dominated by Aspergillus oryzae JI-4 exhibited strong antifungal and antimycotoxigenic activities against aflatoxigenic Aspergillus flavus and ochratoxigenic Penicillium verrucosum both in vitro and in situ. Furthermore, co-inoculation with Koji JI and mycotoxigenic fungi in the early stage of Doenjang fermentation significantly suppressed aflatoxins and ochratoxin A production by more than 93% (p < 0.05) and improved the nutritional properties and sensory qualities of the final product. These results suggest that the addition of commercial Koji could be an effective and practical approach to reduce aflatoxins and ochratoxin A contamination during the fermentation of soybean paste.

Ultrasound-induced yield increase of yuba (protein-lipid film from soybean milk) and changes in structural, physicochemical, and digestive properties during film-peeling process

Yuba, as a traditional soybean food, is protein-lipid film from soybean milk. This study proposed a novel ultrasound-assisted yuba preparation strategy and investigated the structural, physicochemical, and digestive properties of yuba during the film-peeling process. The process parameters of yuba preparation were optimized using response surface method and Box-Behnken design. The results showed that total yield of 5 yuba films was 39.8 ± 0.3% under the optimum conditions (315 W ultrasound power, 8 min ultrasound time, and 1:9 solid-to-liquid ratio) with an increase rate of 12.6%, compared with that of the control group. With the increasing yuba film-peeling times, protein and lipid contents in yuba decreased, whereas carbohydrate content displayed an increasing trend. The analyses of mechanical properties, protein secondary structure, X-ray diffraction, disulfide bond, and microstructure showed that the protein network structure of yuba films became looser with film-peeling progression. Furthermore, in vitro simulated digestion experiments indicated that yuba obtained in the early film-peeling stage (the first four films) exhibited better protein degradation performance and higher degree of lipid hydrolysis. This study provides technical references for the process innovations of yuba and theoretical basis for systematically evaluating yuba quality and better utilizing its nutritional value.

Novel misos shape distinct microbial ecologies: opportunities for flavourful sustainable food innovation

Fermentation is resurgent around the world as people seek healthier, more sustainable, and tasty food options. This study explores the microbial ecology of miso, a traditional Japanese fermented paste, made with novel regional substrates to develop new plant-based foods. Eight novel miso varieties were developed using different protein-rich substrates: yellow peas, Gotland lentils, and fava beans (each with two treatments: standard and nixtamalisation), as well as rye bread and soybeans. The misos were produced at Noma, a restaurant in Copenhagen, Denmark. Samples were analysed with biological and technical triplicates at the beginning and end of fermentation. We also incorporated in this study six samples of novel misos produced following the same recipe at Inua, a former affiliate restaurant of Noma in Tokyo, Japan. To analyse microbial community structure and diversity, metabarcoding (16S and ITS) and shotgun metagenomic analyses were performed. The misos contain a greater range of microbes than is currently described for miso in the literature. The composition of the novel yellow pea misos was notably similar to the traditional soybean ones, suggesting they are a good alternative, which supports our culinary collaborators’ sensory conclusions. For bacteria, we found that overall substrate had the strongest effect, followed by time, treatment (nixtamalisation), and geography. For fungi, there was a slightly stronger effect of geography and a mild effect of substrate, and no significant effects for treatment or time. Based on an analysis of metagenome-assembled genomes (MAGs), strains of Staphylococccus epidermidis differentiated according to substrate. Carotenoid biosynthesis genes in these MAGs appeared in strains from Japan but not from Denmark, suggesting a possible gene-level geographical effect. The benign and possibly functional presence of S. epidermidis in these misos, a species typically associated with the human skin microbiome, suggests possible adaptation to the miso niche, and the flow of microbes between bodies and foods in certain fermentation as more common than is currently recognised. This study improves our understanding of miso ecology, highlights the potential for developing novel misos using diverse local ingredients, and suggests how fermentation innovation can contribute to studies of microbial ecology and evolution.

Correlation between monosaccharide, oligosaccharide, and microbial community profile changes in traditional soybean brick (meju) fermentation

Meju is essential for making diverse traditional fermented soybean foods in Korea. To understand the changes in carbohydrates during fermentation, we aimed to identify autochthonous microorganisms from spontaneously fermented meju and compare the alterations in monosaccharides and oligosaccharides throughout the fermentation process. Microbial diversity was determined using a metabarcoding approach, and monosaccharide and oligosaccharide profiles were obtained by HPLC-Q-TOF MS and HPLC-MS/MS analyses, respectively. The dominant bacterial genera were Weissella, Lactobacillus, and Leuconostoc, while Mucor was highly abundant in the fungal community. The total monosaccharide content increased from Day 0 to Day 50, with the highest amount being 4.37 mg/g. Oligosaccharide profiling revealed the degradation of soybean dietary fiber during fermentation, and novel oligosaccharide structures were also discovered. Correlation analysis revealed that the fungus Mucor was positively related to pentose-containing oligosaccharides, galactose, and galacturonic acid, indicating that Mucor may degrade soybean dietary fibers such as xylogalacturonan, arabinogalactan, and rhamnogalacturonan. The negative relationships between the abundances of Weissella and oligo- and monosaccharides suggested that the bacteria may utilize saccharides for fermentation. These findings provide insights into the mechanisms underlying carbohydrate degradation and utilization; the key components involved in saccharide transformation that contribute to the characteristics of traditional meju were subsequently identified.

Extensive analysis of monosaccharide diversity in fermented soybean paste using LC-MS/MS

Doenjang, a widely consumed fermented soybean paste in Korea, contains abundant carbohydrates. However, the composition of various monosaccharides present in fermented foods has not been thoroughly investigated. Thus, we used a rapid and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to simultaneously analyze monosaccharides in the soybean paste. The method exhibited excellent linearity, sensitivity, and accuracy as confirmed by spiking experiments. In the soybean paste, we identified 11 monosaccharides, with galactose, glucose, and arabinose being predominant, alongside galacturonic acid, N-acetylglucosamine, and glucuronic acid. Analyzing 8 modified and 9 traditional soybean paste samples from different regions, we found a significant correlation between manufacturing method and monosaccharide profiles, with traditional soybean paste exhibiting greater monosaccharide diversity. This method is adaptable for rapid and efficient analysis of monosaccharides in various fermented foods.

Microbial communities in the fermentation of Meju, a Korean traditional soybean brick.

Meju is a traditional Korean soybean brick characterized by diverse microbial communities. The microbial communities in Meju were identified at the phylum and genus levels using high-throughput sequencing. During Meju fermentation, diverse factors such as total bacterial cell numbers, moisture content, salinity, pH, enzyme activities, and free amino acids were monitored. After 30days of fermentation, microbial adaptation and increased protease activity resulted in significant changes, including an increase in pH and alterations in free amino acid content by day 70. Bacterial community analysis revealed significant changes in Bacillus, Lactococcus, and Enterococcus levels as fermentation progressed. The decrease in pH during fermentation was influenced by lactic acid bacteria, which affected bacterial dynamics. At the end of fermentation, the fungal community was dominated by Monascus, Aspergillus, and Scopulariopsis, which affected the free amino acid levels. These results indicate that pH and moisture content may be significant factors in determining microbial communities.

Mathematical modeling of optimal coagulant dosage for tofu preparation using MgCl2

To explore the association between the optimal coagulant for tofu and the components of soybeans,30 different kinds of soybeans were selected, and tested for their optimal coagulant MgCl2 content. The optimal amount of coagulant was taken as the dependent variable, and the soybean Composition were taken as independent variables for the correlation analysis. The results showed that there was a positive correlation between the optimal coagulant content and the content of histidine, 7S β-conglycinin, B1aB1bB2B3B4 of 11 s glycincin, and α'-subunit of 7S β-conglycinin, negative correlation with lysine. The regression formula is y = -1.186 + 3.457*B1aB1bB2B3B4 + 2.304*7S + 0.351*histidine − 0.084*lysine + 4.696*α', and the model is validated to be within 10 % of the error value and has a high degree of confidence. This study provides theoretical support for realizing the green production of traditional soybean products.

Traditional soybean fermentation of Meitei of Manipur

Traditional soybean fermentation of Meitei of Manipur

Effect of Peony (Paeonia ostii) Seed Meal Supplement on Enzyme Activities and Flavor Compounds of Chinese Traditional Soybean Paste during Fermentation.

Peony seed meal (PSM) is the by-product obtained from peony seeds after oil extraction. In this study, PSM was incorporated into traditional koji-making, and its impacts on koji enzyme activities and flavor compounds in final products were investigated. In the process of koji fermentation, the optimal addition ratio of PSM to soybean was determined as 7:3. Under this ratio, the maximum enzyme activities of neutral protease, amylase, and glucoamylase were 1177.85, 686.58, and 1564.36 U/g, respectively, and the koji obtained was subjected to maturation. During post-fermentation, changes in the fermentation characteristics of the paste samples were monitored, and it was found that compared to the soybean paste without PSM, the enzyme activities maintained at a relatively good level. The PSM soybean paste contained a total of 80 flavor compounds and 11 key flavor compounds (OAV ≥ 1), including ethyl isovalerate, isovaleric acid, hexanal, phenylacetaldehyde, 3-Methyl-1-butanol 4-heptanone, 2-pentylfuran, methanethiol ester caproate, isoamyl acetate, 3-methyl-4-heptanone, and isovaleraldehyde. These findings could be used to improve the quality of traditional fermented paste, enrich its flavor, and simultaneously promote PSM as a valuable resource for fermented foods.

Screening lactic acid bacteria and yeast strains for soybean paste fermentation in northeast of China.

Soybean paste was a traditional fermented product in northeast China, mainly fermented by molds, yeast, Bacillus, and lactic acid bacteria. In this study, the safety and fermentation ability of lactic acid bacteria and yeast strains isolated from traditional soybean paste in northeast China were evaluated, and the dynamic changes of biogenic amines, aflatoxin, total acids, amino acid nitrogen, and volatile compounds were investigated during the fermentation of the traditional soybean paste. Among the tested strains, Lactiplantibacillus plantarum DPUL-J8 could decompose putrescine by 100%, and no biogenic amine was produced by Pichia kudriavzevii DPUY-J8. Lactiplantibacillus plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 with strong biogenic amine degrading capacities were inoculated into the soybean paste. After 30 days of fermentation, the content of biogenic amines and aflatoxin in the fermented soybean paste declined by more than 60% and 50%, respectively. At the same time, compared with the control group without inoculation, the contents of total acid (1.29 ± 0.05 g/100 g), amino acid nitrogen (0.82 ± 0.01 g/100 g), and volatile compounds in soybean paste fermented by L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 were significantly increased, which had a good flavor. These results indicated that the use of L. plantarum DPUL-J8 and P. kudriavzevii DPUY-J8 as starter cultures for soybean paste might be a good strategy to improve the safety and flavor of traditional Chinese soybean paste.

Comparative Analysis of Microbial and Mycotoxin Contamination in Korean Traditional Soybean Paste and Soy Sauce Production with and without Starter

Doenjang and ganjang are traditional, Korean fermented foods. They are manufactured by fermenting jangs, either through the traditional natural fermentation, using straw, or the commercial inoculating starter cultures. However, both Bacillus cereus and aflatoxins have been detected in jangs, compromising their safety. Aflatoxins have been detected on numerous occasions. However, studies are yet to be conducted on whether these safety issues differ depending on the manufacturing method. In this study, we evaluated whether the manufacturing methods of doenjang and ganjang alter their safety. Samples of traditional and commercial doenjang and ganjang were analyzed for aflatoxin and B. cereus contamination. Microbiome taxonomic profiling was performed to assess microbial composition. The experimental methodology involved sample collection from various stages of production, including the use of starter cultures and natural fermentation processes. Aflatoxin levels were determined using regulatory limits, and B. cereus content was evaluated against specific thresholds. Aflatoxins were detected in both traditional and commercial doenjang and ganjang, with either the total aflatoxin (15 μg/kg) or aflatoxin B1 (10 μg/kg) exceeding the regulatory limits. However, ochratoxin A was not detected in any of the samples. B. cereus was detected in some samples, within the regulatory limit (4 log CFU/g), and was not influenced by the manufacturing method. Analysis at the production stage showed that aflatoxin increased alongside the fermentation time in traditional doenjang. However, in ganjang, no significant differences were associated with the fermentation period. When using starter cultures, the fermentation period did not affect the toxin level in both foods. Both methods showed lower aflatoxin content in the initial doenjang and ganjang samples than in meju. B. cereus was not detected in either method, as its content decreased over the fermentation period. Microbiome taxonomic profiling confirmed that even when using starter cultures, B. cereus was not a dominant species and was considerably affected by the environment. Staphylococcus aureus and Pseudomonas, pathogenic in nature, were detected in products manufactured using the traditional method; hence, the potential risk of this method was higher than that of the commercial method. The experimental methodology employed in this study contributes to understanding the microbial composition and toxin contamination levels in doenjang and ganjang, contributing to the overall knowledge of their safety and quality control.

Ecological assessment of soil contamination with heavy metals due to the application of mineral fertilisers

The article presents the results of monitoring the aftereffect of the use of excessive zonal doses of mineral fertilisers on soil contamination with heavy metals (HM). With traditional soybean cultivation technology, the level of soil contamination when applying excessive doses (N 60P 180K 90) of fertilisers is quite high and indicates violations of the ecological balance of the agroecosystem. By the nature of the accumulation of heavy metals in meadow-chestnut soil, depending on the application of the studied doses (P 60K 30, N 30P 60K 30, N 60P 180K 90) of fertiliser, the content of HM (Pb, Zn, Cd) increases. The greatest contamination of the soil with Cu was revealed, the content of which increases to 3.2 mg∙kg –1 of soil, which is higher than the threshold of the maximum permissible concentration (MPC) – 3.0 mg∙kg–1. According to the level of contamination of the soil with copper, it belongs to the highly dangerous classes. In a comparative assessment of the level of soil contamination with HM, optimal norms of mineral fertilisers have been established, namely, against the background of effective resource-saving technology for growing soybeans. The application of fertilisers at a dose of P 60K 30 and N 30P 60K 30 does not significantly affect the level of soil contamination with HM, optimises the ecological state and nutrient regime of the soil, preserves and restores soil fertility indicators, and increases soybean productivity. This resource-saving technology provides a safe environment for soybean cultivation and a significant increase of 34.5–38.6% in crop productivity (0.53–0.76 Mg∙ha –1) and yield (2.57 Mg∙ha –1).

Trends in Quality Characteristics Changes of Traditional Soybean Fermented Foods by Supplementary Ingredients Addition

Trends in Quality Characteristics Changes of Traditional Soybean Fermented Foods by Supplementary Ingredients Addition

Multiresponse optimization of biodiesel obtained from a mixture of soybean oil, beef tallow, and waste cooking oil

Biodiesel is considered an alternative fuel that offers socio-environmental advantages over regular diesel from fossil origin. Several feedstocks can produce biodiesel, but animal fat and waste cooking oil (WCO) have become attractive due to their low cost and easy availability. These feedstocks can be mixed with traditional soybean oil to improve biodiesel’s properties, such as oxidation stability and cloud point, which would help comply with the quality parameters required by law. This work aimed to optimize pure biodiesel (B100) production from the mixture of soybean oil, beef tallow, and WCO by the methyl route and homogeneous (basic) catalysis. The simplex-centroid mixture experimental design was used to optimize yield, Induction Period (IP), and Cold Filter Plugging Point (CFPP). The results indicated that the optimum formulation was a mixture containing 50% soybean oil, 33% beef tallow, and 17% WCO. The quality parameters evaluated are within limits established by international legislation; IP of 7.11 h and CFPP of 0 °C. The real values of the R2, p-values, or t-values validate the obtained models.

Characterization of Nonaflatoxigenic Aspergillus flavus/oryzae Strains Isolated from Korean Traditional Soybean Meju

Filamentous fungi that could be classified into Aspergillus flavus/oryzae were isolated from traditionally fermented meju commercially available in Korea. The samples were analyzed for aflatoxin B1 and ochratoxin A contamination by HPLC; however, no toxin was detected. In addition, fungal and bacterial metagenomic sequencing were performed to analyze the microbial distribution in the samples. The results revealed that the distribution and abundance of fungi and bacteria differed considerably depending on the production regions and fermentation conditions of the meju samples. Through morphological analysis, ITS region sequencing, and assessment of the aflatoxin-producing ability, a total of 32 A. flavus/oryzae strains were identified. PCR analysis of six regions with a high mutation frequency in the aflatoxin gene cluster (AGC) revealed a total of six types of AGC breaking point patterns. The A. flavus/oryzae strains did not exhibit the high amylase activity detected in the commercial yellow koji strain (starter mold). However, their peptidase and lipase activities were generally higher than that of the koji isolates. We verified the safety of the traditionally fermented meju samples by analyzing the AGC breaking point pattern and the enzyme activities of A. flavus/oryzae strains isolated from the samples. The isolated strains could possibly be used as starter molds for soybean fermentation.

Mapping of Alternative Oilseeds from the Brazilian Caatinga and Assessment of Catalytic Pathways toward Biofuels Production

Biofuels are increasingly important renewable resources in the world’s energy matrix that have challenged the scientific community as well as small and large farmers to develop alternatives to fossil fuels in order to achieve the aims of energy transition. In particular, Brazil’s proven competitiveness in agribusiness together with its rich biodiversity put the country in a key position in the biofuels market. The semiarid Caatinga of northeastern Brazil, an exclusive biome rich in many oilseed species suitable for potential energy purposes, is of particular interest in this field. Nowadays, soybeans are the main feedstock used for the production of biodiesel, but, due to the increasing demand for biofuels, the search for alternative sources of oil from tropical flora with high productivity is crucial. Under this premise, this systematic review focuses on mapping Caatinga’s vegetable oil crops that could be used as alternative raw materials for biofuels’ production in Brazil, in addition to traditional soybeans and sugarcane. To gain more detailed insight into these matrices, their main properties, including oil content, fatty acid profile and physicochemical properties, are discussed. Moreover, an overview is provided of processes to synthesize different types of biofuels, particularly biodiesel and aviation biokerosene, including the routes employing homogeneous, enzymatic and mainly heterogeneous catalysts. Finally, future prospects and challenges for renewable biofuels and the Caatinga biome are addressed.

Research on intelligent storage technology of agricultural products -- taking soybean as an example

As an important cash crop, soybeans are often used to squeeze oil and as high-quality livestock feed, providing residents with high-quality vegetable oil and meat supplies, and play an important role in improving the health of the national diet. At present, the yield of soybeans in China is low, and many demand loopholes rely on high-quality soybeans imported from abroad to fill, so safe storage is particularly important. Based on this, this paper excavates and analyzes the problems existing in the traditional soybean storage method, and takes targeted measures according to the problems exposed by the traditional soybean storage, and constructs a real-time monitoring system for the soybean storage environment in the warehouse by using a variety of new storage technology means to improve the safe storage capacity and national living standards of soybeans in China.

Effect of the changs of microbial community on flavor components of traditional soybean paste during storage period

Soybean paste is a tradition of fermented soybean paste products under natural conditions. This study used high-throughput sequencing and headspace-solid phase microextraction combined with gas chromatography-mass spectrometry to determine soybean paste's microbial communities and volatile components at different storage periods. Data analysis determined the key flora and their effects on flavor substances. The results showed that acids, phenols and pyrazines contributed the most to the flavor of soybean sauce in different storage periods. Mucor, Bacillus, Lactobacillus, Candida, Kroppenstedtia and Clostridium_sensu_stricto_12 played a vital role in the key flavor components. This study revealed a significant relationship between soybean paste flavour and colonies in different storage periods.

Synthesis and Properties of Supramolecular Crops Based on PNZST Antiferroelectric Film

With the rapid development of ecological agriculture and the continuous changes of the ecological environment, crops are facing tremendous challenges. At the same time, people’s demand for the number and variety of crops is gradually increasing, so the synthesis and performance improvement of crops is imminent. The emergence of supramolecular crops has brought about huge changes in the yield of crops. In this paper, for the purpose of reducing the cost of crops and enhancing the ability of crops to adapt to the environment, PNZST antiferroelectric film materials are used to study the synthesis of supramolecular crops. Among them, rice, corn, and soybeans are used as reference objects for synthetic crops. Experiments were carried out in four aspects: growth rate, growth cycle, and yield. The growth status of the three crops in the past four years was monitored and recorded and analyzed. The survival rate of traditional rice was 86.3%–89.5%, the growth cycle was 86–90 days, and the yield was 69–77 kg/ha; the survival rate of traditional corn was 85.6%–89%, the growth cycle was 105–114 days, and the yield was 38–43 kg/ha; the survival rate of traditional soybean was 85.6%–89%, the growth cycle was 85–90 days, and the output was 14–16 kg/ha. The survival rate of synthetic rice was 95.5%–96.9%, the growth cycle was 63–66 days, and the yield was 83–86 kg/ha; the survival rate of synthetic corn was 97.3%–98.7%, the growth cycle was 85–95 days, and the yield was 53–56 kg/ha; the survival rate of synthetic soybeans was 96.3%–98.3%, the growth cycle was 59–68 days, and the yield was 29–33 kg/ha.

Comparative Effects of Traditional Versus Genetically Modified Soybean Oils on Colon Tumorigenesis in Mice.

Soybean oil, which has high abundance of linoleic acid (LA, 18:2ω-6), is the most commonly consumed edible oil. Recent studies support that a high dietary intake of LA is linked with increased risks of developing colonic inflammation and colon cancer. Here we studied the effects of the genetically modified Plenish® soybean oil, which has low abundance of LA as well as α-linolenic acid (ALA, 18:3ω-3), on development of azoxymethane (AOM)/dextran sulfate sodium (DSS)-induced colon tumorigenesis in mice. Compared with a diet rich in traditional soybean oil, administration of a diet enriched with the Plenish oil has little impact on AOM/DSS-induced colon tumorigenesis, colonic infiltration of immune cells, expressions of inflammatory genes, and tumor markers. These results suggest that the traditional and the Plenish soybean oils have similar effects on development of AOM/DSS-induced colon cancer in mice.