Comparisons of nutritional constituents in soybeans during solid state fermentation times and screening for their glucosidase enzymes and antioxidant properties

Extraction of polysaccharides from Camellia oleifera leaves by dual enzymes combined with deep eutectic solvents screened by ANN and COSMO-RS

Camellia oleifera leaves were byproduct of the C. oleifera industry which was rich in polysaccharides. Deep eutectic solvent-dual enzyme system (DES-dEAE) was established to achieve the simultaneous hydrolysis reaction of dual enzymes and DES extraction. Currently, there was a lack of research methods that simultaneously deal with the relationship between DES and enzymes and the effect of DES on the polysaccharide extraction rate. In the study, artificial neural network (ANN) and conductor-like screening model for real solvents (COSMO-RS) were used to screen the most suitable DES by predicting the pH and activity coefficient of DESs. Choline chloride and sorbitol constituted the best DES and were used to optimize the process conditions of DES-dEAE by response surface method (RSM). The polysaccharide yield was verified to be 21.46 mg/g with the optimal process conditions: liquid-solid ratio of 33:1, enzyme ratio of 3:1, extraction time of 15 min and water content of 40 %. The C. oleifera polysaccharides obtained by water, DES, and DES-dEAE extractions were observed by scanning electron microscopy and cell wall damage effect of DES-dEAE was confirmed microscopically. The study optimized the complex polysaccharide extraction system using bioinformatics methods, contributing new ideas to the development of simulated extraction.

Process optimization of co-fermentation natto with Lactobacillus bulgaricus and characteristic analysis

Natto is a functional food, but it produces an unpleasant smell during the fermentation process. To eliminate the unacceptable smell, Lactobacillus bulgaricus and Bacillus subtilis were used to co-ferment soybeans in this study. The optimal conditions of co-fermentation anaerobic fermentation were: fermentation time 20 h, temperature 35 °C, strain ratio 1:1, and inoculum amount 4%. After optimization, fibrinolytic activity, antioxidant activity, polyphenol content, and γ-polyglutamic acid (γ-PGA) yield of Natto were increased by 15.2%, 10.9%, 29.1%, and 72.3%. It also introduced a wealth of probiotics with lactic acid bacteria up to 1.45 X 1010cfu/g. The co-fermented natto had unique fruity and lactic flavor, and high sensory score based on the flavor and sensory analysis. The activity and value of natto have been increased through co-fermentation, making it possible to improve natto.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-024-06062-5.

Exploring the effect of soybean fermentation broth (S-FB) on gut microbes of lipopolysaccharide (LPS)-infected loach (Misgurnus anguillicaudatus) using 16S rRNA sequencing

The fermentation products of soybean are rich in beneficial bacteria, which play Shenghui Chu a significant role in maintaining the balance of intestinal microbiota and improving intestinal health. To investigate the immunomodulatory effects of soybean fermentation broth (S-FB) on loach (Misgurnus anguillicaudatus) with lipopolysaccharide (LPS)-induced enteritis, 16S rDNA high-throughput sequencing technology was employed to analyze the composition and structure of intestinal microbiota in two groups: the LPS-treated group (fed with soybean broth) and the control group (normal feeding conditions). The results revealed that the relative abundance of beneficial bacteria, such as Lactobacillus and Muribaculaceae, significantly increased in the treatment group, while the relative abundance of harmful bacteria, including Aeromonas and Shewanella, decreased. These findings suggest that soybean fermentation broth can repair intestinal damage and maintain intestinal health by enhancing the abundance of beneficial bacteria and reducing the pathogenic effects of harmful bacteria on the host. Functional prediction studies of microbial communities also showed that treatment groups primarily affected metabolic and genetic information processing. The research results analyzed the changes in the structure and distribution of intestinal microflora in different groups of loach, providing new insights into the possible role of soybean fermentation liquid in intestinal inflammation.

Enhancing the Phytochemicals and Antioxidant Abilities of Isoflavone-Enriched Soybean Leaves Through Inoculation with Lacticaseibacillus paracasei LAB47 and Levilactobacillus brevis WCP02

In this study, Lacticaseibacillus paracasei LAB47 (LAB47) and Levilactobacillus brevis WCP02 (WCP02) were selected for the fermentation of isoflavone-enriched soybean leaves (IESLs) according to their survival capability under artificial gastric acid, β-glucosidase activity, γ-aminobutyric acid (GABA) production ability, and isoflavone contents. The strain ratio and fermentation duration with LAB47 and WCP02 for IESLs were 1:1 (per 2.5%, v/v) with a fermentation time of 72 h. Finally, the fermented IESLs (FIESLs) were compared with the raw and steamed IESLs (RIESLs and SIESLs, respectively) to determine the fatty acids, free amino acids, isoflavones, antioxidant activities, digestive inhibitory activities, and DNA protection capacity. The contents of total fatty acids (1295.67 mg/100 g), GABAs (101.39 mg/100 g), total phenolics (33.73 gallic acid equivalents mg/g), total flavonoids (13.93 rutin equivalents mg/g), and isoflavone aglycones (2588.85 μg/g) were higher in FIESLs than in RIESLs and SIESLs. In addition, the IC50 inhibition of glucosidase (2.85 mg/mL) and pancreatic lipase (4.38 mg/mL) and DNA damage protection activities were superior in FIESLs than in RIESLs and SIESLs. Therefore, FIESLs with LAB47 and WCP02 increased the phytochemical and antioxidant activities of IESLs and may be used as functional foods.

Comparison of primary and secondary metabolites and antioxidant activities by solid-state fermentation of Apios americana Medikus with different fungi

This study compared the nutritional components, isoflavones, and antioxidant activities by solid-sate fermentation of Apios americana Medikus (AAM) with seven different fungi. The total fatty acid contents increased from 120.5 mg/100 g (unfermented AAM, UFAAM) to 242.0 to 3167.5 mg/100 g (fermented AAM, FAAM) with all fungi. In particular, the values of total fatty acids were highest (26.3-fold increase) in the FAAM with Monascus purpureus. The amount of total free amino acids increased from 591.69 mg/100 g (UFAAM) to 664.38 to 1603.07 mg/100 g after fermentation except for Monascus pilosus and Lentinula edodes. The total mineral contents increased evidently after fermentation with M. purpureus, F. velutipes, and Tricholoma matsutake (347.36 → 588.29, 576.59, and 453.32 mg/100 g, respectively). The UFAAM predominated isoflavone glycosides, whereas glycoside forms were converted into aglycone forms after fermentation by fungi. The bioconversion rates of glycoside to aglycone were excellent in the FAAM with M. pilosus, M. purpureus, F. velutipes, and T. matsutake (0.01 → 0.69, 0.50, 0.27, and 0.31 mg/g, respectively). Furthermore, the total phenolic contents, total flavonoid contents, and antioxidant activities by the abovementioned FAAM were high except for L.edodes. This FAAM can be used as a potential food and pharmaceutical materials.

Dynamic changes on sensory property, nutritional quality and metabolic profiles of green kernel black beans during Eurotium cristatum-based solid-state fermentation

Eurotium cristatum, a unique probiotic in Fu brick tea, is widely used in food processing to enhance added values. Here, green kernel black beans (GKBBs) were solid-fermented with E. cristatum and dynamic changes in flavour, chemical composition and metabolites during fermentation were investigated. As results, E. cristatum fermentation altered aroma profiles and sensory attributes of GKBBs, especially reduced sourness. After fermentation, total polyphenolic and flavonoid contents in GKBBs were elevated, while polysaccharides, soluble proteins and short-chain fatty acids contents were decreased. E. cristatum fermentation also induced biotransformation of glycosidic isoflavones into sapogenic isoflavones. During fermentation, dynamic changes in levels of 17 amino acids were observed, in which 3 branched-chain amino acids were increased. Non-targeted metabolomics identified 51 differential compounds and 10 related metabolic pathways involved in E. cristatum fermentation of GKBBs. This study lays foundation for the development of green kernel black bean-based functional food products with E. cristatum fermentation.

Characterization and discrimination of volatile organic compounds and α-glucosidase inhibitory activity of soybeans (Glycine max L.) during solid-state fermentation with Eurotium cristatum YL-1

In this study, the influence of solid-state fermentation (SSF) using probiotic Eurotium cristatum on the change of volatile organic compounds (VOCs) and α-glucosidase inhibition activity of soybeans was investigated. A total of 46 VOCs were characterized via headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS), the majority of which were aldehydes (17), alcohols (10), and ketones (7). SSF by E. cristatum drastically affected the flavor characteristics of soybeans, and the levels of unpleasant beany flavor components, such as hexanal-D, 1-octen-3-ol, 1-hexanol-D, 1-hexanol-M, heptanal-M, 1-pentanol, heptanal-D, and 2-pentyl furan were all substantially decreased by 50% after 15 days of SSF, while volatiles with floral, caramel, and desirable flavors such as pentanal-D, methylpropanal, 2-propanol, and propyl acetate drastically (p < 0.05) increased by 1.1-, 19.2-, 3.6-, and 2.6-fold, respectively. Key aroma-active compounds analysis revealed that 18 VOCs (ROAV, relative odor activity value ≥ 1) play a great role in shaping the flavor characteristics of the soybean samples. After 15 days of SSF, the ROAV values of methylpropanal, 2-propanol, and propyl acetate drastically (p < 0.05) increased to 8.48, 63.88, and 11.29, respectively, which greatly contributed to the desirable flavor characteristics of fermented soybeans. Furthermore, E. cristatum greatly improved the α-glucosidase inhibitory activity of soybean by 22.4% after 15 days fermentation, which was closely correlated with the accumulated phenolic compounds during SSF. Molecular docking showed that genistein and daidzein have high binding affinity for α-glucosidase active sites, primarily driven by hydrogen bonds and hydrophobic interactions. These results demonstrated that soybeans fermented with E. cristatum substantially improved the flavor characteristics and α-glucosidase inhibitory effect, and were greatly helpful to promote the application of soybeans in food products.

Emerging production techniques and potential health promoting properties of plant and animal protein-derived bioactive peptides

Bioactive peptides (BPs) are short amino acid sequences that that are known to exhibit physiological characteristics such as antioxidant, antimicrobial, antihypertensive and antidiabetic properties, suggesting that they could be exploited as functional foods in the nutraceutical industry. These BPs can be derived from a variety of food sources, including milk, meat, marine, and plant proteins. In the past decade, various methods including in silico, in vitro, and in vivo techniques have been explored to unravel underlying mechanisms of BPs. To forecast interactions between peptides and their targets, in silico methods such as BIOPEP, molecular docking and Quantitative Structure-Activity Relationship modeling have been employed. Additionally, in vitro research has examined how BPs affect enzyme activities, protein expressions, and cell cultures. In vivo studies on the contrary have appraised the impact of BPs on animal models and human subjects. Hence, in the light of recent literature, this review examines the multifaceted aspects of BPs production from milk, meat, marine, and plant proteins and their potential bioactivities. We envisage that the various concepts discussed will contribute to a better understanding of the food derived BP production, which could pave a way for their potential applications in the nutraceutical industry.

Synchronous reducing anti-nutritional factors and enhancing biological activity of soybean by the fermentation of edible fungus Auricularia auricula

Auricularia auricula fermentation was performed to reduce anti-nutritional factors, improve nutritional components, and enhance biological activity of soybean. Results showed that the contents of raffinose, stachyose, and trypsin inhibitor were significantly decreased from initial 1.65 g L-1, 1.60 g L-1, and 284.67 μg g-1 to 0.14 g L-1, 0.35 g L-1, and 4.52 μg g-1 after 144 h of fermentation, respectively. Simultaneously, the contents of polysaccharide, total phenolics, and total flavonoids were increased, and melanin was secreted. The isoflavone glycosides were converted to their aglycones, and the contents of glyctin and genistin were decreased from initial 1107.99 μg g-1 and 2852.26 μg g-1 to non-detection after 72 h of fermentation, respectively. After 96 h of fermentation, the IC50 values of samples against DPPH and ABTS radicals scavenging were decreased from 17.61 mg mL-1 and 3.43 mg mL-1 to 4.63 mg mL-1 and 0.89 mg mL-1, and those of samples inhibiting α-glucosidase and angiotensin I-converting enzyme were decreased from 53.89 mg mL-1 and 11.27 mg mL-1 to 18.24 mg mL-1 and 6.78 mg mL-1, respectively, indicating the significant increase in these bioactivities. These results suggested A. auricula fermentation can enhance the nutritional quality and biological activity of soybean, and the fermented soybean products have the potential to be processed into health foods/food additives.

Comparison of microbial diversity and metabolites on household and commercial doenjang

In this study, the microbial diversity, free amino acid (FAA), and biological activities of household doenjang (HDJ) from four different regions and commercial doenjang (CDJ) four manufacturers were analyzed. And volatile flavor compound (VFC) and isoflavone profiles were analyzed using gas chromatograph-mass spectrometer (GC-MS) and high performance liquid chromatography (HPLC), respectively. The major bacterial genus in 1HDJ and 2HDJ was Bacillus (97.5%), while in 3HDJ and 4HDJ, it was Enterobacter (47.5%) and Pseudomonas (80%), respectively. Tetragenococcus was the main bacterial genus of CDJ. The Zygosaccharomyces genus among yeast was comparatively high in all samples. In all samples, glutamic acid predominated among the FAAs, and the 3-methyl butanal, benzeneacetaldehyde, and diallyl disulphide were major VFCs. CDJ contained higher levels of isoflavone-glycoside and total phenolics. Except for 3HDJ and 4CDJ, the isoflavone-aglycone and total flavonoid contents were higher in HDJ. The correlation between bacterial genus and metabolited of doenjang showed that Tetragenococcus was closely related to glutamic acid, Bacillus was related to aglycones and ammonia, and Pseudomonas was highly related to isovaleric acid. While, correlation between yeast genus and metabolited of doenjang confirmed that Candida, Hanseniaspora, and Saccharomyces were related with furfural, benzeneacetaldehyde, and 3-methyl butanal, respectively. The results of this study can be utilized as basic data for the industrialization and development of doenjang.

Enhancing the functionality of plant-based Yogurt: Integration of lycopene through dual-stage fermentation of soymilk

Well-defined compositional assemblies of plant-based yogurt are of fast-growing awareness for world population concerning environmental sustainability, economic burdens and health risks. Soybean is an attractive candidate for plant yogurt, suffering from poor flavor, limited nutrition, and undesired allergens to offer healthy-functional segments. Herein, we deciphered a novel lycopene-soy yogurt by efficient two-stage fermentation of engineered B. subtilis and LAB. The fortified sogurt was ensured with redundant lycopene of 22.67 ± 2.95 mg/g DCW by engineered B. subtilis and enriched soy isoflavone from synergistic effects of engineered B. subtilis and LAB, possessing strong antioxidant capacity for upgrading functionality. Moreover, the desired pH, accelerated protein hydrolysis, enhanced amino acid availability, and expected sensory attributes cooperatively conferred lycopene-soy yogurt as healthy functional food. High potential is firstly ascribed to sequential dual culture of engineered B. subtilis and LAB in lycopene-soy yogurt, in which flavorful, hypoallergenic and antioxidative ingredients enabled functionalities for plant-based yogurt.

Fermentation of soybeans with Pleurotus cornucopiae and Pleurotus ostreatus increases isoflavone aglycones, total polyphenol content and antioxidant activity

Edible basidiomycetes are highly active in the oxidative decomposition and polymerisation of polyphenols, and soybeans contain large amounts of isoflavones, which are polyphenol glycosides. Isoflavone aglycones exhibit weak estrogenic activities. In this study, we investigated the isoflavone content, polyphenol production, antioxidant activity and ergothioneine (EGT) content of soybeans fermented by Pleurotus cornucopiae and Pleurotus ostreatus. Isoflavone glycosides, which were abundant in unfermented soybeans, decreased, and aglycones increased on day 10 of culture in both edible basidiomycete-fermented soybeans. The total maximum polyphenol content in soybeans fermented by both mushrooms were approximately 4 times higher on day 30 to 40 of culture, than that of unfermented soybeans. P. cornucopiae-fermented soybeans showed maximum antioxidant activity on day 20 of culture, and this was approximately 6.1 times higher than that of unfermented soybeans. EGT was not detected in unfermented soybeans, whereas both fermented soybeans showed a maximum EGT content on day 20 of culture, which was especially high in P. cornucopiae-fermented soybeans. The antioxidant activity and EGT of P. cornucopiae-fermented soybeans were higher than those of P. ostreatus, suggesting that EGT was responsible for the increase in the antioxidant activity of P. cornucopiae-fermented soybeans.

The Effect of Germination and Fermentation on the Physicochemical, Nutritional, and Functional Quality Attributes of Samh Seeds

This study investigated the effects of fermentation and germination on the physicochemical, nutritional, functional, and bioactive quality attributes of samh seeds. Regardless of the processing treatment, samh seeds were found to be a rich source of phenolic compounds, namely gallic acid (79.6-96.36 mg/100 g DW), catechol (56.34-77.34 mg/100 g DW), and catechin (49.15-84.93 mg/100 g DW), and they possessed high DPPH antiradical activity (65.27-78.39%). They also contained high protein content (19.29-20.41%), essential amino acids content (39.07-44.16% of total amino acids), and unsaturated fatty acid content (81.95-83.46% of total fatty acids) and a low glycemic index (39.61-41.43). Fermentation and germination increased L*, b*, foaming capacity, oil absorption capacity (OAC), water absorption capacity (WAC), swelling power, microbial counts, antioxidant activity, total flavonoid content (TFC), total phenolic content (TPC), in vitro protein digestibility, protein efficiency ratio, and total essential amino acids and reduced water solubility, emulsion stability, tannin, and phytate contents compared to raw samh seeds (p < 0.05). The highest levels of pH, ash, carbohydrate, fiber, and glycemic index were observed in raw samh seeds, and both germination and fermentation processes reduced these attributes to various degrees (p < 0.05). Germination increased the redness (a*), moisture content, essential and non-essential amino acids, potassium, zinc, phosphorous, stearic acid, and oleic and unsaturated fatty acids and reduced total solids, fat content, iron, zinc, calcium, magnesium, sodium, palmitic acid, and total saturated fatty acids of the samh seeds compared to the raw ones. Fermentation increased the total solid, acidity, fat, protein, calcium, magnesium, sodium, phosphorous, iron, zinc, palmitic acid, and total saturated fatty acids and reduced the a* value, moisture, non-essential amino acids, and total unsaturated fatty acids of the samh seeds compared to the raw ones. In conclusion, samh seeds are a rich source of nutrients that could generally be enhanced by germination and fermentation processes. The reported information facilitates strategies towards the application of these underutilized seeds in foods.

Changes in Nutrient Components and Digestive Enzymatic Inhibition Activities in Soy Leaves by Ethephon Treatment

In this study, the high isoflavone-enriched soy leaves (IESLs) were manufactured by treating with the chemical inducer ethephon, a plant growth regulator, to confirm changes in the properties of soy leaves (SLs), which are underutilized. Ethephon treatment concentrations consisted of 0 (SL1), 150 (SL2), and 300 (SL3) μg/mL. The composition analysis and physiological activity were conducted according to the ethephon treatment concentration of SLs. There was no significant difference in the proximate composition and fatty acids, except for an increase with increasing ethephon treatment concentrations. Depending on the ethephon treatment concentration, free amino acids increased to 1413.0, 1569.8, and 2100.4 mg/100 g, and water-soluble vitamins increased to 246.7, 244.7, and 501.6 mg/100 g. In particular, the functional substance isoflavone increased significantly to 1430.11, 7806.42, and 14,968.00 μg/g. Through this study, it was confirmed that the nutritional components and isoflavones of SLs increased according to the ethephon treatment concentration, a chemical inducer treatment agent. This can be used as a high-value-added biosubstance for raw materials for functional foods, cosmetics, and for natural drugs.

Effects of Polygonatum sibiricum on Physicochemical Properties, Biological Compounds, and Functionality of Fermented Soymilk

The purpose of this study was to investigate the effects of Polygonatum sibiricum (P. sibiricum) on microbial fermentation, physicochemical properties, and functional properties of fermented soymilk. Three types of fermented soymilk were prepared. The first type was fermented directly from regular soymilk (fermented soymilk, FSM), and the other two were fermented after adding P. sibiricum (P. sibiricum fermented soymilk, P-FSM) or P. sibiricum polysaccharides (P. sibiricum polysaccharides fermented soymilk, PP-FSM). The differences in physical and chemical indexes such as pH value, acidity, and water-holding capacity were mainly compared, and the differences in the contents of functional components such as total phenols, total flavonoids, soy isoflavones, γ-aminobutyric acid, and organic acids were compared. The functionalities of the three samples in terms of antioxidant activity were evaluated, and the relevance of each active substance was explored. Compared with the FSM group, the addition of P. sibiricum and P. sibiricum polysaccharides could not only significantly promote the fermentation of Lactobacillus but also significantly improve the stability of the finished products during storage and prolong the shelf life of the finished product. The conversion rates of glycoside soybean isoflavones in the PP-FSM and P-FSM groups were 73% and 69%, respectively, which were significantly higher than those in the FSM group (64%). At the end of fermentation, the γ-aminobutyric acid contents of the PP-FSM and P-FSM groups were 383.66 ± 1.41 mg/L and 386.27 ± 3.43 mg/L, respectively, while that of the FSM group was only 288.66 ± 3.94 mg/L. There were also great differences in the content and types of organic acids among the three samples, especially lactic acid and acetic acid. By comparing the antioxidant capacity of DPPH (1,1-Diphenyl-2-picrylhydrazyl free radical), AB-TS (2,2'-Azinobis-3-ethylbenzthiazoline-6-sulphonate), and iron chelation, it was found that both PP-FSM and P-FSM were superior to FSM, and the antioxidant capacity had a certain correlation with the contents of total phenols and total flavonoids.

Comparisons of Physicochemical Properties, Bacterial Diversities, Isoflavone Profiles and Antioxidant Activities on Household and Commercial doenjang

In this study, the physicochemical properties (pH, acidity, salinity, and soluble protein), bacterial diversities, isoflavone contents, and antioxidant activities of doenjang (fermented soy paste), household doenjang (HDJ), and commercial doenjang (CDJ), were assessed and compared. The values of pH 5.14-5.94 and acidity 1.36-3.03%, indicated a similar level in all doenjang. The salinity was high in CDJ at 12.8-14.6%, and the protein contents (25.69-37.54 mg/g) were generally high in HDJ. Forty-three species were identified from the HDJ and CDJ. The main species were verified to be Bacillus amyloliquefaciens (B. amyloliquefaciens), B. amyloliquefaciens subsp. plantarum, Bacillus licheniformis, Bacillus sp. and Bacillus subtilis. Comparing the ratios of isoflavone types, the HDJ has an aglycone ratio of >80%, and 3HDJ indicates a ratio of isoflavone to aglycone of 100%. In the CDJ, except 4CDJ, glycosides account for a high proportion of more than 50%. The results of antioxidant activities and DNA protection effects were variedly confirmed regardless of HDJs and CDJs. Through these results, it is judged that HDJs have a variety of bacterial species compared to CDJs, and these are biologically active and converted from glycoside to aglycone. Bacterial distribution and isoflavone contents could be used as basic data.

Effects of characteristics of douchi during rapid fermentation and antioxidant activity using different starter cultures

BACKGROUND

As a traditional Chinese condiment, douchi has attracted attention in Asian and European countries because of its high nutrient content and unique flavors. Douchi is currently produced mostly by natural fermentation. The quality of douchi produced in this way is affected by microbial species, temperature, humidity, and season, so the physical and chemical properties of the product, the content of flavor substances, and its safety vary. In this study, four safe strains with high protease activity, screened previously, namely Bacillus velezensis, Bacillus amyloliquefaciens, Lichtheimia ramosa, and Lichtheimia corymbifera, were used as starter cultures for douchi fermentation.

RESULTS

After 35 days, the results showed that the pH, titratable acids, free amino-type nitrogen, amino acids, the total number of colonies, and neutral protease activity of all samples had reached an average level. Through gas chromatography-mass spectrometry (GC-MS), the content of key aroma substances aldehydes and esters was higher than in commercial douchi and the free amino acid content of douchi fermented by the four strains was three to five times that of commercial douchi. Douchi fermented by Bacillus amyloliquefaciens had more flavor substances and the highest 2, 2-diphenyl-1-(2, 4, 6-trinitrophenyl) hydrazyl (DPPH) free radical scavenging rates of 92.4%. Four samples yielded total phenolic content and soy isoflavones in the range of 0.98-1.93 g kg^-1 and 0.58-0.89 g kg^-1 , respectively.

CONCLUSION

These findings indicate that the use of a high-protease activity starter to produce douchi can improve the quality of douchi to a certain extent. The douchi obtained using Bacillus amyloliquefaciens not only has a good flavor but also has a high level of antioxidant activity. © 2023 Society of Chemical Industry.

A novel Stauntonia leucantha fruits arabinogalactan: and structural characterization

Polysaccharides were the key ingredients of many herbal medicines, and were responsible for multiple pharmacological activities. In this study, a novel polysaccharide fraction, named SLP-2, was isolated from Stauntonia leucantha fruits, and purified by DEAE-52 and Sephadex G-100 column chromatography. Furthermore, SLP-2 was identified by congo red, methylation, partial acid hydrolysis and NMR. The results indicated that the backbone of SLP-2 was composed of →4)-β-D-Galp-(1 → 4)-β-D-Galp-(1→ substituted at C-6 with 1,5-linked arabinan. SLP-2 had good anti-oxidation ability in vitro. Surprisingly, we found that reduction of carboxyl groups and methylation of hydroxyl groups enhanced the ability to scavenge 2,2'-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and inhibit lipid peroxidation, and weakened the activity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reduce ferric iron.

Physicochemical characterization of a fern polysaccharide from Alsophila spinulosa leaf and its anti-aging activity in Caenorhabditis elegans

Alsophila spinulosa , as a rare tree fern with potential medicinal value, has attracted extensive attention. Herein, the physicochemical properties, antioxidant and anti-aging activities of polysaccharide from A. spinulosa leaf (ALP) were investigated. ALP was composed of galactose, arabinose, glucose, rhamnose, galacturonic acid, mannose, and fucose. (1→), (1→6), and (1→2) bond types were the primary glycosidic bond in ALP. Surprisingly, ALP displayed the wonderful activity of antioxidant and anti-aging, including excellent scavenging ability against DPPH and ABTS radicals in vitro ; prolonging the life span, improving activity of antioxidative enzymes (SOD and CAT), and decreasing the level of ROS, MDA in Caenorhabditis elegans . Meanwhile, ALP promoted DAF-16 to move into the nuclear. Overall, our results illustrated that ALP could be further developed as a functional food ingredient.

Enhancing organic selenium content and antioxidant activities of soy sauce using nano-selenium during soybean soaking

Nano-selenium has a greater potential than inorganic selenium in preventing selenium-deficiency diseases due to its higher safety. In this study, spherical nano-selenium particles (53.8 nm) were prepared using sodium selenite, ascorbic acid and chitosan. Selenium-enriched soy sauces were prepared by soaking soybean in nano-selenium and sodium selenite solutions (2–10 mg/L), respectively. Total selenium and organic selenium contents of soy sauces prepared by nano-selenium and sodium selenite were increased by 32–191-fold and 29–173-fold compared to the control (without selenium), and organic selenium accounted for over 90% of total selenium. Soy sauce prepared using 6 mg/L nano-selenium had the strongest antioxidant activities, which were 9.25–28.02% higher than the control. Nano-selenium (6 mg/L) markedly enhanced the koji's enzyme activities (9.76–33.59%), then the latter promoted the release of total phenolics (27.54%), total flavonoids (27.27%) and the formation of free amino acids (16.19%), Maillard reaction products (24.50%), finally the antioxidant activities of selenium-enriched soy sauce were enhanced.

Changes in Chemical Compositions and Antioxidant Activities from Fresh to Fermented Red Mountain-Cultivated Ginseng

This study investigated changes in nutrients (fatty acids, amino acids, and minerals), ginsenosides, and volatile flavors, and antioxidant activities during food processing of mountain-cultivated ginseng (MCG) with the cocktail lactic acid bacteria. Fatty acid content increased, but the free amino acid content decreased, and minerals were practically unaffected during processing. Total phenolic and flavonoid contents and maillard reaction products increased markedly according to processing stage. The total ginsenosides levels increased from 31.25 mg/g (DMCG) to 32.36 mg/g (red MCG, RMCG) and then decreased (27.27 mg/g, at fermented RMCG) during processing. Particularly, the contents of F2 (0.31 → 1.02 → 2.27 mg/g), Rg3 (0.36 → 0.77 → 1.93 mg/g), and compound K (0.5 → 1.68 → 4.13 mg/g) of ginsenosides and β-panasinsene (17.28 → 22.69 → 31.61%), biocycloelemene (0.11 → 0.84 → 0.92%), δ-cadinene (0.39 → 0.5 → 0.94%), and alloaromadendrene (1.64 → 1.39 → 2.6%) of volatile flavor compounds increased during processing, along with to the antioxidant effects (such as DPPH, ABTS, and hydroxyl radical scavenging activities, and FRAP). This study may provide several choices for the use of ginseng in functional foods and functional cosmetics.

Comprehensive Comparison of Chemical Composition and Antioxidant Activity of Panax ginseng Sprouts by Different Cultivation Systems in a Plant Factory

In this study, the primary (such as amino acids, fatty acids, and minerals) and secondary (including ginsenosides, phenolic acids, and flavonols) metabolites and antioxidant effects of Panax ginseng sprouts (PGSs) by different cultivation systems, such as soil–substrate cultivation (SSC) and deep-water cultivation (DWC), in a plant factory has been observed. There was no significant difference in the total fatty acid (FA) contents. Particularly, the major FAs of PGSs were palmitic acid (207.4 mg/100 g) of saturated FAs and linoleic acid (397.6 mg/100 g) and α-linolenic acid (222.6 mg/100 g) of unsaturated FAs in the SSC system. The values of total amino acids were all higher in SSC than in DWC. In the case of ginsenosides, the total protopanaxtriol product was 30.88 mg/g in SSC, while the total protopanaxdiol product was 34.83 mg/g in DWC. In particular, the values of total phenolic acids and total flavonols were 133.36 and 388.19 ug/g, respectively, and SSC had a higher content than DWC. In conclusion, the SSC system was shown to be higher in nutritional constituents and antioxidant activities in soil cultivation, suggesting that PGS with SSC has a positive effect on the quality of PGS in a plant factory.

Daidzin inhibits hepatocellular carcinoma survival by interfering with the glycolytic/gluconeogenic pathway through downregulation of TPI1

Daidzin (DDZ) is a natural brassin-like compound extracted from the soybean, and has been found to have therapeutic potential against tumors in recent years. This study investigates the therapeutic effect of DDZ on hepatocellular carcinoma cells and elucidates the possible mechanisms of action. The viability of HCCLM3 and Hep3B cells was detected by MTT assay. Western blots and qPCR were used to detect the protein and mRNA levels of proliferation and apoptosis related genes. Gas chromatography-mass spectrometry (GC-MS) was used for metabolome analysis. In vivo antitumor effects were assessed in nude mice engrafted with HCC cell lines. Our results show that DDZ treatment dose-dependently inhibited cell viability, migration, and survival. The expressions of CDK1, BCL2, MYC, and survivin were reduced, while the expressions of BAX and PARP were increased in DDZ treated cells. The differentially expressed metabolites detected in DDZ treated cultures are associated with glycolysis/gluconeogenesis pathways. Bioinformatic analysis identified TPI1, a gene in the glycolysis pathway with prognostic value for hepatocellular carcinoma (HCC), and DDZ treatment downregulated this gene. In vivo experiments show that DDZ significantly reduced the tumor volume and weight, and inhibited Ki67 expression within tumors. This study shows that DDZ interfered with the survival and migration of hepatocellular carcinoma cells, likely via TPI1 and the gluconeogenesis pathway.

Occurrence of isoflavones in soybean sprouts and strategies to enhance their content: A review

Sprouting is a common strategy to enhance the nutritional value of seeds. Here, all the reports regarding the occurrence of isoflavones in soybean sprouts have been covered for the first time. Isoflavones were detected with concentrations ranging from 1 × 10-2 to 1 × 101  g/kg in soybean sprouts. Isoflavone concentration depends on the cultivar, germination time, part of the sprout, light, and temperature. Aglycon isoflavones increased during germination, especially in the hypocotyl, while 6″-O-malonyl-7-O-β-glucoside isoflavones decreased in the hypocotyl and increased in the cotyledon and root. Cooking reduced total isoflavone content. Regarding the strategies to enhance isoflavone contents, fermentation with Aspergillus sojae and external irradiation with UV-A or far-infrared were the methods that caused the greatest increases in aglycon, 7-O-β-glucoside, and total isoflavones. However, the largest increases in 6″-O-malonyl-7-O-β-glucoside and 6″-O-acetyl-7-O-β-glucosides isoflavones were detected after treatment with chitohexaose and calcium chloride, respectively. PRACTICAL APPLICATION: Soybean sprouts are widely consumed and provide essential proteins, antioxidants, and minerals. They are rich in isoflavones, which exhibit numerous health benefits, and have been studied as alternative therapies for a range of hormone-dependent conditions, such as cancer, menopausal symptoms, cardiovascular disease, and osteoporosis. Despite numerous reports being published to date regarding the occurrence of isoflavones in soybean sprouts, the publications in this field are highly dispersed, and a review has not yet been published. This review aims to (1) highlight the particular isoflavones that have been detected in soybean sprouts and their concentrations, (2) compared the effects of temperature, light, cooking and soybean cultivar affect the isoflavone levels on the different parts of the sprout, and (3) discuss the efficacy of the methods to enhance isoflavone contents. This review will provide a better understanding of the current state of this field of research by comparing the general trends and the different treatments for soybean sprouts.

Dynamics and correlation of microbial communities and metabolic compounds in doenjang-meju, a Korean traditional soybean brick

To investigate the general fermentation characteristics of doenjang-meju (a Korean traditional soybean brick), they were periodically collected from eight different manufacturers during all fermentation stages, and their microbial communities and metabolic compounds (metabolites and volatile compounds) were analyzed. Bacillus and/or lactic acid bacteria (LAB, mainly Enterococcus) and Aspergillus were abundant during fermentation. Fructose and glucose; glycerol; acetate and lactate; and cadaverine, putrescine, tyramine, and histamine were identified as the major sugars, carbon compound, organic acids, and biogenic amines, respectively. Tetramethylpyrazine, butyric acid, butyl butyrate, butanol, acetic acid, 2-methylbutyrate, acetoin, 2,3-butandiol, and nonadecane were the major volatile compounds. However, the profiles of microbial communities, metabolites, and volatile compounds during fermentation varied significanlty among samples. Principal component analysis revealed that doenjang-meju had two differentiated fermentation features, Bacillus-dominated fermentation and LAB (mainly Enterococcus)-dominated fermentation, each having different metabolite and volatile compound profiles. Particularly, fewer volatile compounds were detected in LAB-dominated doenjang-meju samples. Correlation analysis showed a strong negative correlation between Bacillus and LAB, and bacteria and fungi were less correlated with each other. Enterococcus, LAB, and Bacillus were positively correlated with lactate, flavonoid aglycones, and putrescine, respectively, suggesting that they might be mainly responsible for producing the compounds during fermentation. This study provides insights into the general fermentation characteristics of doenjang-meju.

Modern Methods of Pre-Treatment of Plant Material for the Extraction of Bioactive Compounds

In this review, recent advances in the methods of pre-treatment of plant material for the extraction of secondary metabolites with high biological activity are presented. The correct preparation of the material for extraction is as important as the selection of the extraction method. This step should prevent the degradation of bioactive compounds as well as the development of fungi and bacteria. Currently, the methods of preparation are expected to modify the particles of the plant material in such a way that will contribute to the release of bioactive compounds loosely bonded to cell wall polymers. This review presents a wide range of methods of preparing plant material, including drying, freeze-drying, convection drying, microwave vacuum drying, enzymatic processes, and fermentation. The influence of the particular methods on the structure of plant material particles, the level of preserved bioactive compounds, and the possibility of their release during the extraction were highlighted. The plant material pre-treatment techniques used were discussed with respect to the amount of compounds released during extraction as well their application in various industries interested in products with a high content of biologically active compounds, such as the pharmaceutical, cosmetics, and food industries.

Novel green soybean shuidouchi fermented by Bacillus velezensis with multibioactivities

Soybeans are usually fermented by Bacillus subtilis to produce shuidouchi, which is a traditional fermentation soybean product in China. In the study, green soybeans were fermented by Bacillus velezensis to make a novel green soybean shuidouchi with multibioactivities. The processing conditions were optimized as follows: initial moisture content 75%, inoculum concentration 7 log CFU/g, and incubation time 24 h for prefermentation; water addition 50%, salt addition 6%, temperature 45°C, 3 days for postfermentation. The fermented green soybean shuidouchi (FGSS) showed 234.8 FU/g dry weight (DW) for the fibrinolytic activity and IC50 of 0.33 mg/ml for the anticoagulant activity. FGSS had higher contents of chemical components including 3.6 mg rutin (RE)/g DW of total flavonoids, 8.2 mg gallic acid (GAE)/g DW of total phenolics, 63.7 mg/g DW of reducing sugars, and 163.8 mg/g DW of peptides than the unfermented green soybean shuidouchi (UGSS). Moreover, it exhibited high antioxidant activities of 29.8, 85.1 μmol trolox equivalent (TE)/g DW, and 12.8 μmol Fe2+/g DW through 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt (ABTS), and ferric reducing antioxidant power (FRAP) experiments. Thus, a novel green soybean shuidouchi fermented by B. velezensis owing to multibioactivities can provide a theoretical basis for the further development of functional shuidouchi.

Changes in metabolites with harvest times of seedlings of various Korean oat (Avena sativa L.) cultivars and their neuraminidase inhibitory effects

Oats and their seeds, stems, and leaves are approved for use as safe food ingredients. Oat seedlings are environmentally friendly and are becoming increasingly popular as they provide several health benefits. We used the UPLC-CAD to quantitatively analyze isolated compounds (1-11) between 15 cultivars of oat seedlings and their harvest time. Maximum average amount of total contents of isolated compounds was observed after the harvest time of 5 days (4711.3 mg/100 g), while the minimum was observed after the harvest time of 7 days (4184.8 mg/100 g). We demonstrated that all isolated compounds (1-11) showed neuraminidase inhibitory effects, with 6 and 7 being the most active with IC₅₀ values of 3.7 and 20.5 µM, respectively. High content of compounds 6 and 7 was observed (2306.6 mg/100 g) in the Dahan cultivar at 9 days, indicating potential good cultivars with a high content of active compounds and neuraminidase inhibition activity.

Evaluation of the Antioxidant and Antimicrobial Activities of Ethyl Acetate Extract of Saccharomyces cerevisiae

RESEARCH BACKGROUND

Antioxidants are important compounds present at low concentrations that inhibit oxidation processes. Due to the side effects of synthetic antioxidants, research interest has increased considerably towards finding natural sources of antioxidants that can replace the synthetic ones. The emergence and spread of antibiotic resistance require the development of new drugs or some potential sources of novel medicine. This work aims to extract the secondary metabolites of Saccharomyces cerevisiae using ethyl acetate as a solvent and to determine the antioxidant and antimicrobial activities of these extracted metabolites.

EXPERIMENTAL APPROACH

The antioxidant activity of the secondary metabolites of S. cerevisiae were determined using DPPH, ABTS and FRAP assays. Furthermore, the antimicrobial potential of the ethyl acetate extract of S. cerevisiae against Cutibacterium acnes, Staphylococcus aureus and Staphylococcus epidermidis was assessed.

RESULTS AND CONCLUSION

Five out of 13 of the extracted secondary metabolites were identified as antioxidants. The antioxidant activity of the S. cerevisiae extract exhibited relatively high IC50 of 455.26 and 294.51 μg/mL for DPPH and ABTS respectively, while the obtained FRAP value, expressed as ascorbic acid equivalents, was 44.40 μg/mL. Moreover, the extract had a significant antibacterial activity (p<0.05) against Staphylococcus aureus and Staphylococcus epidermidis at the concentrations of 100 and 200 mg/mL, respectively. However, no inhibitory effect was observed against Cutibacterium acnes as the extract was only effective against the bacterium at the concentrations of 300 and 400 mg/mL (inhibition zones ranging from 9.0±0.0 to 9.3±0.6) respectively (p<0.05). Staphylococcus aureus was highly sensitive to the extract, with a MIC value of 18.75 mg/mL.

NOVELTY AND SCIENTIFIC CONTRIBUTION

This report confirmed the efficacy of the secondary metabolites of S. cerevisiae as a natural source of antioxidants and antimicrobials and suggested the possibility of employing them in drugs for the treatment of infectious diseases caused by the tested microorganisms.

Enhancement of isoflavone aglycone, amino acid, and CLA contents in fermented soybean yogurts using different strains: Screening of antioxidant and digestive enzyme inhibition properties

This study was the first to evaluate changes in isoflavone, amino acid, conjugated linoleic acid (CLA), antioxidant effect, and digestive enzyme inhibition during fermentation of soy-milk to soy-yogurt with L. brevis and L. plantarum. Total average isoflavones were reduced (1318.2 → 971.1 μg/g) with an increase of aglycones (60.2 → 804.9 μg/g, genistein > daidzein > glycitein) in soy powder yogurts (SPYs). Amino acids increased considerably, as did ornithine (average 4.1 → 551.0 mg/g), and CLA showed high variations from not-detected (ND) to 0.5, 0.9 mg/g (cis-9, trans-11) and ND to 0.3, 0.2 mg/g (trans-10, cis-12). Digestive enzyme inhibitions (α-glucosidase, α-amylase, and pancreatic lipase) displayed high activities (average 50.6 → 67.2, 5.2 → 46.4, 10.6 → 51.4%). Moreover, the antioxidant abilities against radicals were elevated as follows: ABTS > DPPH > hydroxyl (average 63.5 → 86.5, 50.2 → 70.3, 39.3 → 55.2%). Specifically, SPY using mixed strains exhibited the greatest enzymatic inhibition and antioxidant capacities.

Metabolite profiling, antioxidant and α-glucosidase inhibitory activities of buckwheat processed by solid-state fermentation with Eurotium cristatum YL-1

Buckwheat was processed by solid-state fermentation (SSF) with the probiotic fungal strain Eurotium cristatum YL-1. The effects of SSF on the phytochemical content, as well as the antioxidant and α-glucosidase inhibitory activities, on buckwheat were revealed. Metabolite differences between non-fermented buckwheat (BW) and E. cristatum fermented buckwheat (FBW) were investigated by LC-MS/MS-based untargeted metabolomics. Results showed that 103 and 68 metabolites remarkably differed between BW and FBW in positive and negative ionization modes, respectively. Most phenolic compounds and alkaloids were significantly up-regulated during SSF. Hydrolytic enzymes (i.e., β-glucosidase, α-amylase, protease, and cellulase) were produced by the filamentous fungus E. cristatum during SSF. In vitro spectrophotometric assays demonstrated that the total phenolics content, ferric reducing antioxidant power, reducing power, scavenging activities of DPPH radical and ABTS⁺, and α-glucosidase inhibitory activity of buckwheat were considerably enhanced after processing by SSF with E. cristatum. Additionally, solvents with different polarities significantly influenced the antioxidant and α-glucosidase inhibitory activities of buckwheat extracts. Our study indicated that processing by SSF with E. cristatum can greatly improve the phytochemical components of buckwheat and consequently contribute to its antioxidant and α-glucosidase inhibitory activities. SSF with E. cristatum is an innovative method for enhancing the health-promoting components and bioactivities of buckwheat.

Phenolic profile, antioxidant and enzyme inhibitory activities of underutilized spices from Central Africa

The aim of the present study is to evaluate phytochemical profile, antioxidant and enzyme inhibitory activity of some underutilized Cameroon spice extracts, viz. The fruit of Xylopia africana, the fruit and the bulb of Aframomum sulcatum; and the bark of Hypodaphnis zenkeri. Four different solvent combinations were used for extraction of phytochemicals. Highest total polyphenol, flavonoid and tannin contents were observed in X. africana extract 10.32 ± 0.49 g gallic acid eq/100 g of dry matter, 146.66 ± 4.15 mg quercetin eq/100 g of dry matter, 452.44 ± 2.7 mg tannic acid eq/100 g spices dry matter. Methanol extracts revealed the presence of chlorogenic acid (0.790-4.312), vanillic acid (0.830-19.768), epicatechin (25.386-34.707), p-coumaric acid (1.127-12.652), protosynapic acid (0.221-186.562) and T-cinnamic acid (3.794-52.58) mg/100 g dry spice by HPLC analysis. Extracts of X. africana and H. zenkeri exhibited higher antioxidant activity: DPPH (182.24 ± 2.41 mg ascorbic acid eq/g dry spice), ABTS (9.247 ± 0.004 g trolox eq/100 g spice), hydroxyl free radicals (729.27 ± 3.07 mg mannitol eq/100 g spice) and reducing power (2.351 ± 0.002 g ascorbic acid equivalent/100 g spice). Positive and high correlations existed between the antioxidant activity of extracts obtained with different methods and their corresponding phenolic content. Extract of A. sulcatum highly inhibited porcine pancreatic lipase whereas, X. africana and H. zenkeri extracts highly inhibited α-amylase (98.82 and 99.54% respectively). These spices could be utilized as natural antioxidant sources for the management oxidative stress, lipid and carbohydrate metabolism related diseases.

Co-fermentation of lentils using lactic acid bacteria and Bacillus subtilis natto increases functional and antioxidant components

We identified lentil products with both nutritional value and antioxidant capacity by studying the changes of probiotics and functional substances during single fermentation with lactic acid bacteria (LAB) or co-fermentation using LAB and Bacillus subtilis natto. After fermentation, the best growth of LAB was observed in anaerobic solid-state co-fermentation, whereby the viable counts of Lactobacillus plantarum TK9 and Lactobacillus paracasei TK1501 reached 2.77 × 109 and 2.78 × 109 CFU/g, respectively. Furthermore, the total phenol and genistin content produced by the two mixed groups, respectively, increased by 0.52- and 0.66-fold, as well as 0.63- and 0.64-fold, compared with unfermented samples. Similarly, the free amino acid content increased by 0.53- and 0.49-fold, respectively. The 50% inhibitory concentrations for the radical-scavenging against 1,1-diphenyl-2-picrylhydrazyl and α-glucosidase inhibitory activity were lower following anaerobic co-fermentation. Consistently, products of anaerobic mixed solid-state fermentation had higher oxygen radical absorbance capacity. Therefore, anaerobic solid-state co-fermentation of lentils using B. subtilis natto may promote the multiplication of LAB and enhance the antioxidant activity of fermented lentil products. PRACTICAL APPLICATION: Simple and efficient food handling is more suitable for industrial production. Co-fermentation is a good method to optimize the fermentation process. Co-culture technology has high potential in terms of functionality and antioxidant capacity.

Policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedling extracts according to cultivar and growth time

Policosanols is a health promoting aliphatic alcohol known as lipid-lowing agent. To enable maximising the functional properties of wheat, this research investigates the policosanol profiles and adenosine 5'-monophosphate-activated protein kinase (AMPK) activation potential of Korean wheat seedlings according to cultivars and growth times. GC-MS revealed six policosanols that differed markedly in content between 17 cultivars, especially, octacosanol (8) showed the most predominant component (49-83%), varying significantly in average concentrations with growth times as 361.4 (3 days) → 613.0 (6 days) → 203.1 (9 days) → 196.5 (12 days) → 50.9 mg/100 g (19 days). The highest average policosanol (738.7 mg/100 g) exhibited after 6 days, while the lowest was 104.4 mg/100 g on 19 days. Moreover, the wheat cultivars including Shinmichal 1, Anbaek, Namhae, and Joah at 6 days may be recommended as potential sources because of high policosanols (921.7-990.6 mg/100 g). Western blot analysis revealed markedly higher AMPK activation in cells treated with the hexane extracts (150-370% at 100 μg/ml) and octacosanol (8) possessed potent AMPK activator (control; 100 → 280% at 200 μg/ml). It is confirmed that the AMPK activation by wheat seedlings are positively related to the highest policosanol content at the 6 days of growth time, independent of the cultivar. Our results may be contributed to enhance the wheat value regarding development of new cultivars and functional foods.

Exploring the Potential for Fungal Antagonism and Cell Wall Attack by Bacillus subtilis natto

To develop more ecologically sustainable agricultural practices requires that we reduce our reliance on synthetic chemical pesticides for crop protection. This will likely involve optimized biocontrol approaches - the use of beneficial soil microbes to attack potential plant pathogens to protect plants from diseases. Many bacterial species, including strains of Bacillus subtilis, have been explored for their biocontrol properties, as they can control the growth of harmful fungi, often by disrupting the fungal cell wall. A strain that is not often considered for this particular application is Bacillus subtilis natto, primarily known for fermenting soybeans via cell wall degradation in the Japanese probiotic dish "natto." Because deconstruction of the fungal cell wall is considered an important biocontrol trait, we were motivated to explore the possible anti-fungal properties of the B. subtilis natto strain. We show that B. subtilis natto can use complex fungal material as a carbon source for growth, and can effectively deconstruct fungal cell walls. We found degradation of fungal cell wall proteins, and showed that growth on a mix of peptides was very strong. We also found that intact fungal cell walls can induce the secretion of chitinases and proteases. Surprisingly, we could show that chitin, the bulk component of the fungal cell wall, does not permit successful growth of the natto strain or induce the secretion of chitinolytic enzymes, although these were produced during exposure to proteins or to complex fungal material. We have further shown that protease secretion is likely a constitutively enabled mechanism for nutrient scavenging by B. subtilis natto, as well as a potent tool for the degradation of fungal cell walls. Overall, our data highlight B. subtilis natto as a promising candidate for biocontrol products, with relevant behaviors that can be optimized by altering growth conditions. Whereas it is common for bacterial biocontrol products to be supplied with chitin or chitosan as a priming polysaccharide, our data indicate that this is not a useful approach with this particular bacterium, which should instead be supplied with either glucose or attenuated fungal material.

Bioprocessing of soybeans (Glycine max L.) by solid-state fermentation with Eurotium cristatum YL-1 improves total phenolic content, isoflavone aglycones, and antioxidant activity

In this study, soybean (Glycine max L.) was bioprocessed with fungal strain Eurotium cristatum YL-1 by using the solid-state fermentation (SSF) technique. The effect of SSF on total phenolic content (TPC), isoflavone compositions, and antioxidant activity of soybean during different fermentation periods was evaluated. Results showed that TPC and isoflavone aglycones were significantly increased, whereas glucoside isoflavones were remarkably reduced during SSF. After 15 days of SSF, the TPC, daidzein, genistein, and total aglycones of soybeans were approximately 1.9-, 10.4-, 8.4-, and 9.4-fold higher, respectively, than those of non-fermented soybeans. During SSF, β-glucosidase activity was very high, whereas α-amylase and protease activities were at moderate levels, and cellulase activity was relatively low. A highly positive correlation was found between TPC and the activities of α-amylase (correlation coefficient R² = 0.9452), β-glucosidase (R² = 0.9559), cellulase (R² = 0.9783), and protease (R² = 0.6785). Linear analysis validated that the β-glucosidase produced by E. cristatum contributed to the bioconversion of soybean isoflavone glucosides into their aglycone forms. The DPPH radical and ABTS˙⁺ scavenging activity, reducing power, and ferric reducing antioxidant power of soybeans were considerably enhanced during SSF. Principal component analysis and Pearson's correlation analysis verified that the improvement in TPC and isoflavone aglycone content during SSF was mainly responsible for the improved antioxidant capacity of soybeans. Thus, our results demonstrated that solid-state bioprocessing with E. cristatum is an effective approach for the enhancement of the TPC, isoflavone aglycones, and antioxidant capacity of soybeans. Bioprocessed soybean products might be a healthy food supplement rich in antioxidants compared with non-fermented soybean and thus could be a source of natural antioxidants.

Solid-state bioprocessing with Eurotium cristatum is an effective approach for the enhancement of total phenolic content, isoflavone aglycones, and antioxidant activity of soybeans.

Comparative Evaluation of Six Traditional Fermented Soybean Products in East Asia: A Metabolomics Approach

Many ethnic fermented soybean products (FSPs) have long been consumed as seasoning and protein sources in East Asia. To evaluate the quality of various FSPs in East Asia, non-targeted metabolite profiling with multivariate analysis of six traditional FSPs (Natto; NT, Cheonggukjang; CG, Doenjang; DJ, Miso; MS, Doubanjiang; DB, Tianmianjiang; TM) was performed. Six FSPs could be clearly distinguished by principle component analysis (PCA) and partial least square-discriminant analysis (PLS-DA). Amino acid contents were relatively higher in NT and CG, sugar and sugar alcohol contents were relatively higher in MS and TM, isoflavone glycoside contents were relatively highest in CG, isoflavone aglycon contents were the highest in DJ, and soyasaponin contents were the highest in CG. Antioxidant activity and physicochemical properties were determined to examine the relationships between the FSPs and their antioxidant activities. We observed a negative correlation between isoflavone aglycon contents and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS) activity. Furthermore, the order of ABTS activity of FSPs has a positive correlation with the order of soybean content in the six FSPs. Herein it was found that primary metabolites were affected by the main ingredients and secondary metabolites were most influenced by the fermentation time, and that soybean content contributed more to antioxidant activity than fermentation time.

Effect of Genistein on Cholesterol Metabolism-Related Genes in HepG2 Cell

It has been reported that genistein could improve metabolic syndromes. Our study aimed to investigate the effects and potential mechanisms of genistein on improving cholesterol metabolism in HepG2 cell. HepG2 cells were cultured with 0, 0.01, 1.00, 10.00, and 50.00 µM genistein for 24 hr. The current results showed a dose-dependent manner between genistein and intracellular contents of total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-C), and cellular apolipoprotein A1 (Apo-A1) secretion. TC was increased by 25.69%, meanwhile HDL-C and Apo-A1 were decreased by 56.00% and 25.93%, respectively, when the dosage of genistein was 1.00 µM. Genistein dose-dependently upregulated the protein and mRNA levels of sterol regulatory element binding proteins-2 (SREBP-2), as well as the mRNA levels of low-density lipoprotein receptor (LDLR) and 3-hydroxy-3-methyl glutaryl coenzyme A reductase (HMGCR), by 145.91%, 72.29%, 310.23%, and 123.08%, respectively, when we gave 1.00 µM genistein, indicating that intracellular cholesterol synthesis and absorption of exogenous cholesterol were increased. In addition, the mRNA levels of peroxisome proliferator-activated receptor-γ (PPARγ) and liver X receptor (LXRα), lowered by 58.23% and 34.86% at 0.01 µM genistein, were reduced in a dose-dependent manner. LXRα and ATP-binding cassette transporter A1 (ABCA1) protein levels were significantly (P < 0.05) decreased by 50.35% and 11.60% at 1.00 µM genistein, which indicated that cellular cholesterol efflux was inhibited. Taken together, our results suggested that genistein at dosage of more than 1.00 µM was able to increase the intracellular cholesterol levels by up regulating SREBP-2/LDLR/HMGCR pathway and suppressing PPARγ/LXRα/ABCA1 pathway. PRACTICAL APPLICATION: In this study, genistein appeared to be effective in reducing plasma cholesterol levels due to increase the intracellular cholesterol levels by upregulating cholesterol absorption through SREBP-2/LDLR/HMGCR pathway, and also downregulating cholesterol efflux via PPARγ/LXRα/ABCA1 pathway in vitro. In addition, plasma cholesterol is regarded as the key indicator of atherosclerosis; therefore, we believe that our findings could be used for further exploration on a possible therapeutic application of genistein for atherosclerosis.