Production of bioactive peptides during soybean fermentation and their potential health benefits

Nutritional and in vitro antioxidant activity analyses of formulated soymilk dessert

Soymilk (SM) is nutritionally nearly equal to milk from cows and is free of cholesterol, gluten, and lactose. This study's objective was to formulate a cholesterol-free soymilk dessert (SOD) and compare it's to commercial desserts (CODs). Results indicated that the CODs contain substantial amounts of cholesterol while SOD does not. Soymilk dessert has more protein, and vitamin E than CODs, but less fat and calcium. In addition, the result also highlighted that SOD has higher number of amino acids compared to CODs. The total antioxidant, flavonoids and phenolics content of SOD were significantly higher than CODs. Furthermore, the in vitro antioxidant activity of SOD and CODs by DPPH and ABTS methods revealed that the IC50 of SODs significantly (p < 0.001) lower than CODs, and lower IC50 indicated the higher free radical scavenging power of SODs than CODs. These findings indicated that this non-dairy SOD may provide beneficial protein, as well as minerals, and antioxidants to support the body's various physiological functions.

Plant derived antimicrobial peptides: Mechanism of target, isolation techniques, sources and pharmaceutical applications

Antimicrobial resistance is a global health and development threat which is caused by the excess and prolonged usage of antimicrobial compounds in agriculture and pharmaceutical industries. Resistance of pathogenic microorganisms to the already existing drugs represent a serious risk to public health. Plant sources such as cereals, legumes, fruits and vegetables are potential substrates for the isolation of antimicrobial peptides (AMP) with broad spectrum antimicrobial activity against bacteria, fungi and viruses with novel immunomodulatory activities. Thus, in the quest of new antimicrobial agents, AMPs have recently gained interest. Therefore, AMP can be used in agriculture, pharmaceutical and food industries. This review focuses on various explored and unexplored plant based food sources of AMPs, their isolation techniques and antimicrobial mechanism of peptides. Therefore, the literature discussed in this review paper will prove beneficial the research purposes for agriculture, pharmaceutical and food industries. PRACTICAL APPLICATIONS: Isolation of antimicrobial peptides (AMPs) can be done on industrial scale. AMP isolated from food sources can be used in pharmaceutical and agriculture industries. AMP from natural sources mitigate the problem of antimicrobial resistance. AMP isolated from food products can be used as nutraceutical.

Comparison on Protein Bioaccessibility of Soymilk Gels Induced by Glucono-δ-Lactone and Lactic Acid Bacteria

In this study, the protein bioaccessibility of soymilk gels produced by the addition of glu-cono-δ-lactone (GDL) and fermentation with lactic acid bacteria (LAB) was examined using an in vitro gastrointestinal simulated digestion model. The in vitro protein digestibility, soluble protein content, free amino acids contents, degree of hydrolysis, electrophoretic patterns, and peptide content were measured. The results suggested that acid-induced soymilk gel generated by GDL (SG) showed considerably reduced in vitro protein digestibility of 75.33 ± 1.00% compared to the soymilk gel induced by LAB (SL) of 80.57 ± 1.53% (p < 0.05). During the gastric digestion stage, dramatically higher (p < 0.05) soluble protein contents were observed in the SG (4.79−5.05 mg/mL) than that of SL (4.31−4.35 mg/mL). However, during the later intestinal digestion phase, the results were the opposite. At the end of the gastrointestinal digestion phase, the content of small peptides was not significantly different (p > 0.05) between the SL (2.15 ± 0.03 mg/mL) and SG (2.17 ± 0.01 mg/mL), but SL showed higher content of free amino acids (20.637 g/L) than that of SG (19.851 g/L). In general, soymilk gel induced by LAB had a higher protein bioaccessibility than the soymilk gel coagulated by GDL.

Food protein-derived bioactive peptides for the management of nutrition related chronic diseases

Dietary intervention via modifications of dietary pattern or supplementations of naturally derived bioactive compounds has been considered as an efficient approach in management of nutrition related chronic diseases. Food protein-derived bioactive peptide is representative of natural compounds which show the potential to prevent or mitigate nutrition related chronic diseases. In the past decades, substantial research has been conducted concentrating on the characterization, bioavailability, and activity assessment of bioactive peptides. Although various activities of bioactive peptides have been reported, the activity testes of most peptides were only conducted in cells and animal models. Some clinical trials of bioactive peptides were also reported but only limited to antihypertensive peptides, antidiabetic peptides and peptides modulating blood lipid profile. Hereby, clinical evidence of bioactive peptides in management of nutrition-related chronic diseases is summarized in this chapter, which aims at providing implications for the clinical studies of bioactive peptides in the future.

Fermented Soy Products and Their Potential Health Benefits: A Review

In the growing search for therapeutic strategies, there is an interest in foods containing natural antioxidants and other bioactive compounds capable of preventing or reversing pathogenic processes associated with metabolic disease. Fermentation has been used as a potent way of improving the properties of soybean and their components. Microbial metabolism is responsible for producing the β-glucosidase enzyme that converts glycosidic isoflavones into aglycones with higher biological activity in fermented soy products, in addition to several end-metabolites associated with human health development, including peptides, phenolic acids, fatty acids, vitamins, flavonoids, minerals, and organic acids. Thus, several products have emerged from soybean fermentation by fungi, bacteria, or a combination of both. This review covers the key biological characteristics of soy and fermented soy products, including natto, miso, tofu, douchi, sufu, cheonggukjang, doenjang, kanjang, meju, tempeh, thua-nao, kinema, hawaijar, and tungrymbai. The inclusion of these foods in the diet has been associated with the reduction of chronic diseases, with potential anticancer, anti-obesity, antidiabetic, anticholesterol, anti-inflammatory, and neuroprotective effects. These biological activities and the recently studied potential of fermented soybean molecules against SARS-CoV-2 are discussed. Finally, a patent landscape is presented to provide the state-of-the-art of the transfer of knowledge from the scientific sphere to the industrial application.

Anti-Inflammatory Function of Plant-Derived Bioactive Peptides: A Review

Inflammation is considered to be a crucial factor in the development of chronic diseases, eight of which were listed among the top ten causes of death worldwide in the World Health Organization’s World Health Statistics 2019. Moreover, traditional drugs for inflammation are often linked to undesirable side effects. As gentler alternatives to traditional anti-inflammatory drugs, plant-derived bioactive peptides have been shown to be effective interventions against various chronic diseases, including Alzheimer’s disease, cardiovascular disease and cancer. However, an adequate and systematic review of the structures and anti-inflammatory activities of plant-derived bioactive peptides has been lacking. This paper reviews the latest research on plant-derived anti-inflammatory peptides (PAPs), mainly including the specific regulatory mechanisms of PAPs; the structure–activity relationships of PAPs; and their enzymatic processing based on the structure–activity relationships. Moreover, current research problems for PAPs are discussed, such as the shallow exploration of mechanisms, enzymatic solution determination difficulty, low yield and unknown in vivo absorption and metabolism and proposed future research directions. This work aims to provide a reference for functional activity research, nutritional food development and the clinical applications of PAPs.

Fermented soybean foods: A review of their functional components, mechanism of action and factors influencing their health benefits

After thousands of years of evolution and development, traditional fermented soybean foods, with their unique charm, have gained a stable place in the global market. With the explosive development of modern biological technologies, some traditional fermented soybean foods that possess health-promoting benefits are gradually appearing. Physiologically active substances in fermented soybean foods have received extensive attention in recent decades. This review addresses the potential health benefits of several representative fermented soybean foods, as well as the action mechanism and influencing factors of their functional components. Phenolic compounds, low-molecular-weight peptides, melanoidins, furanones and 3-hydroxyanthranilic acid are the antioxidative components predominantly found in fermented soybean foods. Angiotensin I-converting enzyme inhibitory peptides and γ-aminobutyric acid isolated from fermented soy foods provide potential selectivity for hypertension therapy. The potential anti-inflammatory bioactive components in fermented soybean foods include γ-linolenic acid, butyric acid, soy sauce polysaccharides, 2S albumin and isoflavone glycones. Deoxynojirimycin, genistein, and betaine possess high activity against α-glucosidase. Additionally, fermented soybean foods contain neuroprotective constituents, including indole alkaloids, nattokinase, arbutin, and isoflavone vitamin B12. The anticancer activities of fermented soybean foods are associated with surfactin, isolavone, furanones, trypsin inhibitors, and 3-hydroxyanthranilic acid. Nattokinase is highly correlated with antioxidant activity. And a high level of menaquinones-7 is linked to protection against neurodegenerative diseases. Sufficiently recognizing and exploiting the health benefits and functional components of traditional fermented soybean foods could provide a new strategy in the development of the food fermentation industry.

Insight into the protein degradation during the broad bean fermentation process

Broad bean fermentation is of vital importance in PixianDouban (PXDB) production, as well as a key process for microorganisms to degrade protein, which lays the foundation for the formation of PXDB flavor. In this study, two fungi and bacteria were screened, and their morphology, molecular biology, growth, and enzyme production characteristics were analyzed, and then they were applied to the broad bean fermentation simulation system. The protein, peptide, amino acid, amino nitrogen, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) in the system were evaluated. The results showed that the four microorganisms were Aspergillus oryzae, Aspergillus jensenii, Staphylococcus gallinarum, and Enterobacter hormaeche. Aspergillus oryzae had the highest protease activity at pH 7.0, while the other three strains had better enzyme activity stability under neutral acidic conditions. And the total protein (F1 and F2 were 18.32 g/100 g, 19.15 g/100 g, respectively), peptides (11.79 ± 0.04 mg/g and 12.06 ± 0.04 mg/g), and amino acids (55.12 ± 2.78 mg/g and 54.11 ± 1.97 mg/g) of the fungus experimental groups (F) were higher than the bacterial experimental groups (B). In addition, the enzyme system produced by fungi exhibited a stronger ability for albumin (20 kDa) and glutenin (<30 kDa) deterioration in neutral conditions, while the bacterial enzyme system was more efficient in degrading albumin (<30 kDa) and glutenin (20-30 kDa) in acidic conditions, as indicated by SDS-PAGE. These findings showed that both bacteria and fungi played an important role in the degradation of protein in different fermentation stages of broad bean fermentation.

Practical applications

There is a lack of comprehensive understanding of the protein composition and protein degradation mechanism of broad beans in the fermentation stage of PXDB. This research work explored the differences in the degradation of PXDB fermented protein by different microorganisms, and provided a theoretical basis for optimizing the production of PXDB and improving the quality of PXDB.

A Novel Fermented Rapeseed Meal, Inoculated with Selected Protease-Assisting Screened B. subtilis YY-4 and L. plantarum 6026, Showed High Availability and Strong Antioxidant and Immunomodulation Potential Capacity

A study was conducted to investigate the yield of small peptides from rapeseed meal (RSM) by solid-state fermentation (SSF) with acid-protease-assisting B. subtilis YY-4 and L. plantarum CICC6026 (FRSMP). This study explored the availability, antioxidant capacity and immunomodulation activity. The objective of this study was to develop a novel functional food ingredient to contribute to health improvement. The results showed that the concentrations of soluble peptides and free amino acids significantly increased after fermentation (p < 0.001), and the concentration of small molecular peptides (molecular weight < 1 KDa) significantly increased (p < 0.001). The dense surface microstructure of the RSM after fermentation was changed to be loose and porous. The FRSMP exhibited high availability and high antioxidant activity, and it displayed high immunomodulation activity. The novel fermentation was effective for improving the nutritional and biological properties, which provided a feasible method of enhancing the added value.

Effect of Lactic Acid Fermentation on Legume Protein Properties, a Review

Legume proteins have a promising future in the food industry due to their nutritional, environmental, and economic benefits. However, their application is still limited due to the presence of antinutritional and allergenic compounds, their poor technological properties, and their unpleasant sensory characteristics. Fermentation has been traditionally applied to counteract these inconveniences. At present, lactic acid fermentation of legumes is attracting the attention of researchers and industry in relation to the development of healthier, tasty, and technologically adapted products. Hence, we aimed to review the literature to shed light on the effect of lactic acid fermentation on legume protein composition and on their nutritional, functional, technological, and sensorial properties. The antimicrobial activity of lactic acid bacteria during legume fermentation was also considered. The heterogenicity of raw material composition (flour, concentrate, and isolate), the diversity of lactic acid bacteria (nutriment requirements, metabolic pathways, and enzyme production), and the numerous possible fermenting conditions (temperature, time, oxygen, and additional nutrients) offer an impressive range of possibilities with regard to fermented legume products. Systematic studies are required in order to determine the specific roles of the different factors. The optimal selection of these criteria will allow one to obtain high-quality fermented legume products. Fermentation is an attractive technology for the development of legume-based products that are able to satisfy consumers’ expectations from a nutritional, functional, technological, and sensory point of view.

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.

Aroma compounds and consumer acceptability of soybean paste fermented by lactobacilli

Consumption of soybean-based foods is affected by the flavor of the legume; due to the presence of undesirable compounds called "beany flavors". To solve this problem, the influence of solid state fermentation by lactobacilli on the production of volatile compounds in soybean paste was determined. The volatile's production was measured by gas chromatography. Forty compounds were identified in the different soybean pastes studied. The results showed that fermentation stimulates the production of desirable volatile compounds in foods such as ketones (22-75%) and decreased unpleasant compounds (10-84%).The consumers acceptance study showed that a group of participants (30% approximately) preferred the fermented samples associated with sweet and acid aroma like yogurt. In conclusion, the fermentation positively influences the generation of desirable volatile compounds and completely reduces hexanal in one sample. Therefore, fermentation with the studied strains is a valid strategy to modify the aroma profile of a soybean-based food matrix.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13197-021-05210-5.

Fermentation of black soybean with Bacillus spp. for the production of kinema: changes in antioxidant potential on fermentation and gastrointestinal digestion

Black soybean was fermented with four different potential Bacillus spp., including Bacillus licheniformis K1G, Bacillus subtilis K2B, Bacillus amyloliquefaciens K2G and Bacillus subtilis K2M, isolated from kinema, a traditionally fermented soybean product of Sikkim. Enhancement of antioxidant activity was observed with DPPH radical scavenging activity, reducing power potential and total antioxidant activity in methanolic as well as water extracts. Overall antioxidant activities were found to be higher in fermented black soybean in comparison to yellow soybean, showing its potential for production of kinema. Further, black soybean fermented using different starter was subjected to gastrointestinal digestion using pepsin and pancreatin. Upon gastrointestinal digestion of fermented black soybean changes in antioxidant activity was observed that was found to be reliant on the species and strains applied for fermentation as starter culture. Among different starters used for fermentation, black soybean fermented using B. subtilis K2M had higher DPPH radical scavenging and reducing power activity on gastrointestinal digestion. This study concludes that B. subtilis K2M can be applied for fermentation of black soybean for production of kinema as well as bioactive protein hydrolysates.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s13197-021-05144-y.

Fermentation of Soybean Meal with Lactobacillus acidophilus Allows Greater Inclusion of Vegetable Protein in the Diet and Can Reduce Vibrionacea in the Intestine of the South American Catfish (Rhamdia quelen)

Simple Summary

There is a demand to replace fishmeal with protein sources of plant origin in fish feeds. Biotechnology strategies, such as fermentation, can improve the bioavailability of plant proteins and decrease the presence of antinutrients, optimizing the results obtained. Fermented soybean meal has already been evaluated for different fish species as a replacement for fishmeal, and there is evidence that it can improve the intestinal health of animals. Lactobacillus acidophilus is a strain used as a probiotic in fish feeding but it remains to be evaluated as a potential fermentation bacterium for feed ingredients. This study aimed to evaluate the effect of diets containing different inclusion levels (0%, 7%, 14%, 21% and 28%) of soybean meal fermented by L. acidophilus (SMFL) on the zootechnical performance and intestinal health of South American catfish juveniles (Rhamdia quelen). The inclusion of SMFL up to 21% in replacement of fish meal did not affect the zootechnical performance of fish and also decreased the concentration of Vibrionaceae bacteria present in the intestine compared to the control group. The results demonstrate that fermentation with L. acidophilus enables greater inclusion of soybean protein in South American catfish diets and promotes the control of intestinal pathogenic bacteria.

Abstract

The objective of this study was to evaluate the effect of diets containing different inclusion levels (0%, 7%, 14%, 21% and 28%) of soybean meal fermented by Lactobacillus acidophilus (SMFL) on the zootechnical performance and intestinal health of South American catfish juveniles (Rhamdia quelen). The experimental design was completely randomized with five treatments and four replications and lasted 56 days. Five isoproteic (39% crude protein) and isoenergetic (4300 kcal of gross energy kg⁻¹) diets were formulated where SMFL was included in replacement of fish meal. Two hundred forty South American catfish juveniles (3.0 ± 0.5 g) were distributed in 20 tanks (70 L) connected in a recirculation aquaculture system. At the end of the experiment, the inclusion of SMFL up to 21% in replacement of fish meal did not affect the zootechnical performance and also decreased the concentration of Vibrionaceae bacteria present in the intestine compared to the control group. The amount of total lactic and heterotrophic bacteria, the enzymatic activity and the intestinal morphometry did not differ between dietary treatments. The results demonstrate that fermentation with Lactobacillus acidophilus enables greater inclusion of soybean protein in South American catfish diets and promotes the control of intestinal pathogenic bacteria.

Contamination characteristics and risk assessment of aflatoxins in homemade soybean paste, a traditional fermented soybean food, in South Korea

Soybean paste is manufactured through microbial fermentation and may become contaminated with aflatoxins. Herein, we conducted nationwide large-scale monitoring (n = 1436) over three years (2018-2020) to investigate aflatoxin levels according to geographic, demographic, manufacturing, quality factors, and risk characteristics of homemade soybean paste produced through fermentation. The mean level of total aflatoxins was 5.88 μg/kg (range, 0.01-281.92), with the most common contaminating type being the B type. Aflatoxin levels significantly differed according to the region, age of the manufacturer, type of starter used, and the amino-type nitrogen content and pH of the homemade soybean paste (p < 0.05). Aflatoxin levels was significantly higher when starters were manufactured using the traditional method (inoculation with a naturally occurring strain in the surrounding environment). The aflatoxin exposure level estimated through the average intake of homemade soybean paste in all age groups was 0.1012 ng/kg body weight/day. The risk assessment for the genotoxic and carcinogenic potential of aflatoxins using the margin of exposure approach revealed values of 3705-3954 for average intake of homemade soybean paste, indicating public health concern. These results suggest that follow-up studies and safety management strategies are needed to reduce aflatoxin levels in homemade soybean paste.

Therapeutic peptides: current applications and future directions

Peptide drug development has made great progress in the last decade thanks to new production, modification, and analytic technologies. Peptides have been produced and modified using both chemical and biological methods, together with novel design and delivery strategies, which have helped to overcome the inherent drawbacks of peptides and have allowed the continued advancement of this field. A wide variety of natural and modified peptides have been obtained and studied, covering multiple therapeutic areas. This review summarizes the efforts and achievements in peptide drug discovery, production, and modification, and their current applications. We also discuss the value and challenges associated with future developments in therapeutic peptides.

Current perspectives on the anti-inflammatory potential of fermented soy foods

Fermented soy foods (FSF) are gaining significant attention due to promising health benefits. In recent years, FSF are being studied extensively due to the presence of diverse functional ingredients including active isoflavones and peptides along with essential micronutrients. The process of fermentation is responsible for the enrichment of various bioactive principles in soy-based fermented foods and exclusion of some anti-nutrient factors which are found predominantly in raw soybeans. Emerging evidence suggests that FSF possess immense therapeutic potential against inflammation and associated pathological complications. Extracts prepared from various FSF (e.g. fermented soy paste, milk, and sauce) were found to exert promising anti-inflammatory effects in numerous in vitro and in vivo settings. Moreover, clinical findings highlighted an inverse relationship between consumption of FSF and the prevalence of chronic inflammatory disorders among the communities which habitually consume fermented soy products. Molecular mechanisms underlying the anti-inflammatory role of FSF have been delineated in many literatures which collectively suggest that FSF extracts have regulatory actions over the expression and/or activity of several proinflammatory cytokines, inflammatory mediators, oxidative stress markers, and some other factors involved in the inflammatory pathways. The present review discusses the anti-inflammatory effects of FSF with mechanistic insights based upon the available findings from cell culture, preclinical, and clinical investigations.

Antihypertensive effect of soybean bioactive peptides: A review

Hypertension is a global disease that is extremely harmful to humans. Timely lowering of blood pressure is necessary in order to avoid the occurrence of corresponding complications. This review shows that soy peptides are beneficial in resisting hypertension. One of the advantages is the abundance of raw materials for producing soybean peptides. Secondly, there are no reports of adverse reactions due to soy peptides. Moreover, they exert protective effect against hypertension-induced complications such as long-term memory impairment and kidney damage. However, there are still some obstacles associated with the development of soybean peptides. Therefore, this review is focused on statistical analysis of peptide sequences, amino acid residues, and possible targets of anti-hypertensive soybean peptides. Eventually, it proposes that application of genetic engineering technology to specifically modify the N- and C-terminal of the soybean peptides, and possible targets in identifying the likely drug targets involved in the antihypertensive effects of these peptides.

A complete workflow for discovering small bioactive peptides in foods by LC-MS/MS: A case study on almonds

Identification of bioactive peptides is an increasingly important target for food chemists, particularly in consideration of the widespread application of proteolytic enzymes in food processing. Because the characterization of small peptides by LC-MS/MS is challenging, we optimized a dimethyl labeling technique to facilitate small peptide identification, using almond proteins as a model. The method was validated by comparing the MS/MS spectra of standards and almond-derived peptides in their nonderivatized and derivatized forms. Signal enhancement of a₁ ions was proved to effectively aid in the full-length sequencing of small peptides. We further validated this method using two industrially-relevant protein-rich extracts from almond flour: 1737 medium-sized peptides (5-39 amino acids) and 843 small peptides (2-4 amino acids) were identified. The use of an online bioactive peptide database, complemented by the existing literature, allowed the discovery of 208 small bioactive peptides, whereas for medium-sized peptides, only one was reported being bioactive.

Biosynthesis of c9,t11-conjugated linoleic acid and the effect on characteristics in fermented soy milk

The objective of this work was to investigate the effect of fermentation conditions on c9,t11-conjugated linoleic acid (CLA) synthesized by Lactobacillus casei and the variation of physicochemical characteristics, including pH, viable cell number, syneresis and texture profile, of fermented soy milk (FSM) during storage at 4 °C for 28 days. Fermentation in 7°Brix of soy milk (SM) supplemented with 0.1% linoleic acid and incubated at 37 °C for 72 h was found to be the optimal conditions for c9,t11-CLA biosynthesis. Within the storage of 14 days, viable cell number, total flavonoid content, water-holding capacity, spontaneous syneresis and texture profile in FSM remained stable. During the storage of 28 days, the viable cell number and c9,t11-CLA level were higher than 6.58 log CFU/mL and 816.33 μg/g, respectively.

Purification and characterization of hypoglycemic peptides from traditional Chinese soy-fermented douchi

Douchi is a popular soy-fermented food originated in China, with documented hypoglycemic effect. However, the responsible molecules and the mechanism underlying its beneficial effects remains unclear. Therefore, in this study,...

Impact of solid-state fermentation on factors and mechanisms influencing the bioactive compounds of grains and processing by-products

Cereal and legume grains and their processing by-products are rich sources of bioactives such as phenolics with considerable health potential, but these bioactives suffer from low bioaccessibility and bioavailability, resulting in limited use. Several studies have demonstrated that solid-state fermentation (SSF) with food-grade microorganisms is effective in releasing bound phenolic compounds in cereal and legume products. In this review, we discuss the effect of SSF on cereal and legume grains and their by-products by examining the role of specific microorganisms, their hydrolytic enzymes, fermentability of agri-food substrates, and the potential health benefits of SSF-enhanced bioactive compounds. SSF with fungi (Aspergillus spp. and Rhizopus spp.), bacteria (Bacillus subtilis and lactic acid bacteria (LAB) spp.) and yeast (Saccharomyces cerevisiae) significantly increased the bioactive phenolics and antioxidant capacities in cereal and legume grains and by-products, mainly through carbohydrate-cleaving enzymes. Increased bioactive phenolic and peptide contents of SSF-bioprocessed cereal and legume grains have been implicated for improved antioxidant, anti-inflammatory, anti-carcinogenic, anti-diabetic, and angiotensin-converting-enzyme (ACE) inhibitory effects in fermented agri-food products, but these remain as preliminary results. Future research should focus on the microbial mechanisms, suitability of substrates, and the physiological health benefits of SSF-treated grains and by-products.

Widely targeted metabolomics analysis reveals the effect of fermentation on the chemical composition of bee pollen

Microbial fermentation can break the bee pollen wall. However, the global profiling of bee pollen metabolites under fermentation remains unclear. This study aims to comprehensively elucidate the changes in the composition of bee pollen after microbial fermentation. Ultra-performance liquid chromatography-electron spray ionization-mass spectrometry (UPLC-ESI-MS) based on widely targeted metabolomics analysis was used to compare the chemical composition of unfermented bee pollen (UBP) and fermented bee pollen (FBP). Among the 890 metabolites detected, a total of 668 differential metabolites (classified into 17 categories) were identified between UBP and FBP. Fermentation significantly increased the contents of primary metabolites such as 74 amino acids and derivatives, 42 polyunsaturated fatty acids and 66 organic acids, as well as some secondary metabolites such as 38 phenolic acids, 80 flavone aglycones and 22 phenolamides. The results indicate that fermentation is a promising strategy to improve the nutritional value of bee pollen.

Nutritional Contributions and Health Associations of Traditional Fermented Foods

The growing interest in the consumption and study of traditionally fermented food worldwide has led to the development of numerous scientific investigations that have focused on analyzing the microbial and nutritional composition and the health effects derived from the consumption of these foods. Traditionally fermented foods and beverages are a significant source of nutrients, including proteins, essential fatty acids, soluble fiber, minerals, vitamins, and some essential amino acids. Additionally, fermented foods have been considered functional due to their prebiotic content, and the presence of specific lactic acid bacterial strains (LAB), which have shown positive effects on the balance of the intestinal microbiota, providing a beneficial impact in the treatment of diseases. This review presents a bibliographic compilation of scientific studies assessing the effect of the nutritional content and LAB profile of traditional fermented foods on different conditions such as obesity, diabetes, and gastrointestinal disorders.

"Ethno-microbiology" of ethnic Indian fermented foods and alcoholic beverages

The concept of "ethno-microbiology" is to understand the indigenous knowledge of the Indian people for production of culturally and organoleptically acceptable fermented foods by natural fermentation. About 1000 types of common, uncommon, rare, exotic and artisan fermented foods and beverages are prepared and consumed in different geographical regions by multi-ethnic communities in India. Indian fermented foods are mostly acidic and some are alkaline, along with various types of alcoholic beverages. A colossal diversity of microorganisms comprising bacteria mostly belongs to phylum Firmicutes, filamentous moulds and enzyme- and alcohol-producing yeasts under phyla Ascomycota and Mucoromycota, and few bacteriophages and archaea have been reported from Indian fermented foods. Some microorganisms associated with fermented foods have functionalities and health promoting benefits. "Ethno-microbiology" of ethnic Indian people has exhibited the proper utilisation of substrates either singly or in combination such as fermented cereal-legume mixture (idli, dosa and dhokla) in South and West India, sticky fermented soybean food (kinema and related foods), fermented perishable leafy vegetable (gundruk and related foods), fermented bamboo shoots (soibum and related foods) and fermented fish (ngari and others) in North East India, and fermented meat and sausage-like products in the Indian Himalayas, fermented coconut beverage (toddy) in coastal regions, and various types of naturally fermented milk products (dahi and related products) in different regions of India. This review has also highlighted the "ethno-microbiology" knowledge of the people involving the consortia of essential microorganisms in traditionally prepared amylolytic starters for production of cereal-based alcoholic beverages. The novelty of this review is the interpretation of ethno-microbiological knowledge innovated by ethnic Indian people on the use of beneficial microorganisms for food fermentation to obtain the desired fermented food products for consumption.

Analysis of glyoxal, methylglyoxal and diacetyl in soy sauce

In this study, an analytical method for the determination of α-dicarbonyl compounds (α-DCs), including glyoxal (GO), methylglyoxal (MGO) and diacetyl (DA), in soy sauce was validated using gas chromatography-nitrogen-phosphorus detection. Through Maillard reaction various α-DCs, including GO, MGO and DA have been found in fermented food, dairy products and beverages. The analysis of α-DC was carried out by a derivatisation with o-phenylenediamine. The limit of detection and limit of quantitation were 0.04 and 0.12 μg/kg for GO, 0.04 and 0.13 μg/kg for MGO, and 0.07 and 0.22 μg/kg for DA. The intra- and inter-day accuracy ranged from 92.8 to 109% for GO, from 99.5 to 113% for MGO and from 93.6 to 102% for DA. The intra- and inter-day precision ranged from 3.38 to 12.1% for GO, from 0.67 to 7.65% for MGO and from 1.27 to 9.35% for DA. In 20 commercial soy sauces, α-DCs were found in concentration ranges of 5.60-31.7 μg/mL for GO, 14.4-116 μg/mL for MGO and 0.47-5.48 μg/mL for DA. The developed analytical method could be applied for the determination of α-DCs in soy sauce and motivate investigations related to reducing the content of α-DCs in soy sauce.

Functional relevance and health benefits of soymilk fermented by lactic acid bacteria

The growing interest of consumers towards nutritionally enriched, and health promoting foods, provoke interest in the eventual development of fermented functional foods. Soymilk is a growing trend that can serve as a low-cost non-dairy alternative with improved functional and nutritional properties. Soymilk acts as a good nutrition media for the growth and proliferation of the micro-organism as well as for their bioactivities. The bioactive compounds produced by fermentation of soymilk with lactic acid bacteria (LAB) exhibit enhanced nutritional values, and several improved health benefits including antihypertensive, antioxidant, antidiabetic, anticancer and hypocholesterolaemic effects. The fermented soymilk is acquiring a significant position in the functional food industry due to its increased techno-functional qualities as well as ensuring the survivability of probiotic bacteria producing diverse metabolites. This review covers the important benefits conferred by the consumption of soymilk fermented by LAB producing bioactive compounds. It provides a holistic approach to obtain existing knowledge on the biofunctional attributes of fermented soymilk, with a focus on the functionality of soymilk fermented by LAB.

Diversity of beneficial microorganisms and their functionalities in community-specific ethnic fermented foods of the Eastern Himalayas

The Eastern Himalayan regions of India, Nepal and Bhutan have more than 200 varieties of unsurpassed ethnic fermented foods and alcoholic beverages, which are lesser known outside the world. However, these ethnic foods are region- and community-specific, unique and some are exotic and rare, which include fermented vegetables, bamboo shoots, soybeans, cereals, milk (cow and yak), meats, fishes, and cereal-based alcoholic beverages and drinks. Ethnic communities living in the Eastern Himalayas have invented the indigenous knowledge of utilization of unseen microorganisms present in and around the environment for preservation and fermentation of perishable plant or animal substrates to obtain organoleptically desirable and culturally acceptable ethnic fermented food and alcoholic beverages. Some ethnic fermented products and traditionally prepared dry starters for production of alcoholic beverages of North Eastern states of India and Nepal were scientifically studied and reported till date, and however, limited publications are available on microbiological and nutritional aspects of ethnic fermented foods of Bhutan except on few products. Most of the beneficial microorganisms isolated from some ethnic fermented foods of the EH are listed in microbial food cultures (MFC) safe inventory. This study is aimed to review the updates on the beneficial importance of abundant microbiota and health-promoting benefits and functionalities of some ethnic fermented foods of the Eastern Himalayan regions of North East India, Nepal and Bhutan.

Soybean proteins/peptides: A review on their importance, biosynthesis, vacuolar sorting, and accumulation in seeds

Soybean is one of the most important sources of plant protein and is known for its wide range of agricultural, food, and industrial applications as well as health benefits. Interest in soybean proteins has been steadily growing as progressively more applications and benefits are discovered. This review article is focused on the major seed storage proteins of soybean, their three-dimensional structures, their nutritional importance and bioactive peptides, cellular synthesis, and accumulation in seeds. This will also summarize past efforts in the recombinant production of foreign proteins or bioactive peptides in soybean seed.

A versatile ceramic capillary membrane reactor system for continuous enzyme-catalyzed hydrolysis

As an alternative to classical batch processes, enzyme-catalyzed hydrolysis can also be carried out continuously. To facilitate this, a continuous ceramic capillary membrane reactor system (CCCMRS) was developed which can be operated with various proteolytic enzymes immobilized on the porous ceramic capillary membranes. This system has several advantages over common batch processes regarding stability, reproducibility and controllability and can easily be adapted to optimal reaction conditions and individual preferences. Two exemplary applications utilizing the CCCMRS were carried out and investigated in long-term stability studies. In the first application the continuous enzymatic cleavage of human IgG into the antibody fragments Fab and Fc by immobilized papain was performed. A total volume of 22 mL of 1 mg mL-1 IgG-solution was enzymatically cleaved over a period of 33.3 h. The antibody cleavage products could be detected in an SEC-HPLC over the whole process time thus indicating long-term stability of the continuous hydrolysis process. The second application investigated the continuous digestion of pea and almond protein isolates by immobilized Alcalase resulting in the generation of a large variety of different peptides. This peptide fingerprint remains constant over a long period of time enabling fractionation and thus making the peptides accessible for further bioactivity studies in sufficient quantities. The constant peptide fingerprint could be shown in the RP-HPLC analysis for all 30 samples with a total volume of 29.7 mL collected over a period of 45 h.

Insight into the Antioxidant Effect of Fermented and Non-Fermented Spirulina Water and Ethanol Extracts at the Proteome Level Using a Yeast Cell Model

Spirulina is rich in various antioxidants and nutraceuticals and it has proven to be effective in the treatment of various pathological conditions. This study explores the antioxidant effect of fermented and non-fermented Spirulina extracts on the proteome level using the yeast Saccharomyces cerevisiae as a model organism. Yeast cells were treated with fermented Spirulina water extract (SV), non-fermented Spirulina water extract (NFV), fermented Spirulina ethanol extract (SE), and non-fermented Spirulina ethanol extract (NFE). Cell lysates were prepared, and label-free quantitative proteome analysis was performed. In SV, when compared to NFV samples, the levels of most differentially expressed proteins were upregulated. Alternatively, SE compared to NFE samples showed a significant downregulation for the majority of the analyzed proteins involved in different cellular processes. Additionally, a higher downregulation of stress response related proteins was observed in SE compared to NFE samples, while their abundance in SV samples increased compared to NFV. This study provided a global view, on a proteome level, of how cells cope with exogenous antioxidants and remodel their cellular processes to maintain metabolic and redox balance. Furthermore, it combined for the first time the analysis of different extract effect, including the contribution of lactic acid fermentation to the cell activity.

Bioactive Peptides as Potential Nutraceuticals for Diabetes Therapy: A Comprehensive Review

Diabetes mellitus is a major public health concern associated with high mortality and reduced life expectancy. The alarming rise in the prevalence of diabetes is linked to several factors including sedentary lifestyle and unhealthy diet. Nutritional intervention and increased physical activity could significantly contribute to bringing this under control. Food-derived bioactive peptides and protein hydrolysates have been associated with a number health benefits. Several peptides with antidiabetic potential have been identified that could decrease blood glucose level, improve insulin uptake and inhibit key enzymes involved in the development and progression of diabetes. Dietary proteins, from a wide range of food, are rich sources of antidiabetic peptides. Thus, there are a number of benefits in studying peptides obtained from food sources to develop nutraceuticals. A deeper understanding of the underlying molecular mechanisms of these peptides will assist in the development of new peptide-based therapeutics. Despite this, a comprehensive analysis of the antidiabetic properties of bioactive peptides derived from various food sources is still lacking. Here, we review the recent literature on food-derived bioactive peptides possessing antidiabetic activity. The focus is on the effectiveness of these peptides as evidenced by in vitro and in vivo studies. Finally, we discuss future prospects of peptide-based drugs for the treatment of diabetes.

Assessment of Intestinal Immunity and Permeability of Broilers on Partial Replacement Diets of Two-Stage Fermented Soybean Meal by Bacillus velezensis and Lactobacillus brevis ATCC 367

The effect of soybean peptides from fermented soybean meal on the intestinal immunity and tight junction of broilers was assessed. Roughly, two-stage fermented soybean meal prepared with Bv and Lb (FSBM_B+L), which has nearly three times higher soluble peptides than soybean meal (SBM), and reduced galacto-oligosaccharide (GOS) content and allergen protein. The one-stage fermented by Bv (FSBM_B) has the highest soluble peptides, while commercial lactic acid bacteria (FSBM_L) has the highest Lactic acid bacteria count; these were used to compare the differences in the process. Ross308 broilers (n = 320) were divided into four groups: SBM diet and a diet replaced with 6% FSBM_B+L, FSBM_B, or FSBM_L. The growth performance was recorded during the experiment, and six birds (35-day-old) per group were euthanized. Analysis of their jejunum and ileum showed that the fermented soybean meal significantly improved the villus height in the jejunum (p < 0.05) and reduced the crypt hyperplasia. The FSBM_B group had the highest reducing crypt depth; however, the FSBM_B+L group had the highest villus height/crypt depth in the ileum (p < 0.05). In the jejunum, the relative mRNA of CLDN-1 and Occludin increased 2-fold in the treatments, and ZO-1 mRNA increased 1.5 times in FSBM_L and FSBM_B+L (p < 0.05). Furthermore, the level of NF-κB and IL-6 mRNAs in FSBM_L increased, respectively, by 4 and 2.5 times. While FSBM_B, along with FSBM_B+L, had a 1.5-fold increase in the mRNA of IL-10, that of NF-κB increased 2-fold. FSBM_B+L and FSBM_B singly led to a 2- and 3-fold increase in IL-6 mRNA, respectively (p < 0.05). FSBM_B and FSBM_B+L can also upregulate MUC2 in the jejunum (p < 0.05). In short, using the soybean peptides from two-stage fermented soybean meal can ameliorate the negative factors of SBM and effectively regulate immune expression and intestinal repair, which will help broilers maintain intestinal integrity.

The fermentation-time dependent proteolysis profile and peptidomic analysis of fermented soybean curd

The proteolysis and peptidomic profiles and potential bioactivities of fermented soybean curd (furu) during fermentation were studied. The degree of protein hydrolysis (DH) and peptide content significantly increased with fermentation time (p < 0.05), and reached the highest levels after ripening for 90 days. The variety and abundance of bioactive peptides in furu samples were fermentation-time dependent, and furu ripening for 30 and 90 days showed the highest similarity. An ACE-inhibitor and antioxidant peptides were the two main bioactive peptide components, and their abundance and bioactivities exhibited a significant increase with fermentation and reached the maximum levels at 90 days. All these results indicated that microbial fermentation is an effective way to obtain bioactive peptides with soy-based fermented products, and their effects on health might be explored in future studies. PRACTICAL APPLICATION: This work indicated that microbial fermentation is an effective way to obtain bioactive peptides with soy-based fermented products.

Impact of Bacillus in fermented soybean foods on human health

PURPOSE

Fermented soybean foods (FSF) is popularly consumed in the South-East Asian countries. Bacillus species, a predominant microorganism present in these foods, have demonstrated beneficial and deleterious impacts on human health. These microorganisms produce bioactive compounds during fermentation that have beneficial impacts in improving human health. However, the health risks associated with FSF, food pathogens, biogenic amines (BAs) production, and late-onset anaphylaxis, remain a concern. The purpose of this review is to present an in-depth analysis of positive and negative impacts as a result of consumption of FSF along with the measures to alleviate health risks for human consumption.

METHODS

This review was composed by scrutinizing contemporary literature of peer-reviewed publications related to Bacillus and FSF. Based on the results from academic journals, this review paper was categorized into FSF, role of Bacillus species in these foods, process of fermentation, beneficial, and adverse influence of these foods along with methods to improve food safety. Special emphasis was given to the potential benefits of bioactive compounds released during fermentation of soybean by Bacillus species.

RESULTS

The nutritional and functional properties of FSF are well-appreciated, due to the release of peptides and mucilage, which have shown health benefits: in managing cardiac disease, gastric disease, cancer, allergies, hepatic disease, obesity, immune disorders, and especially microbial infections due to the presence of probiotic property, which is a potential alternative to antibiotics. Efficient interventions were established to mitigate pitfalls like the techniques to reduce BAs and food pathogens and by using a defined starter culture to improve the safety and quality of these foods.

CONCLUSION

Despite some of the detrimental effects produced by these foods, potential health benefits have been observed. Therefore, soybean foods fermented by Bacillus can be a promising food by integrating effective measures for maintaining safety and quality for human consumption. Further, in vivo analysis on the activity and dietary interventions of bioactive compounds among animal models and human volunteers are yet to be achieved which is essential to commercialize them for safe consumption by humans, especially immunocompromised patients.