Vegetable and fermented vegetable juices containing germinated seeds and sprouts of lentil and cowpea

Bioprocessing of Sargassum fusiforme via Lactobacillus Fermentation: Effects on Nutrient Composition, Organoleptic Properties, and In Vitro Antioxidant and Hypoglycemic Activities

Sargassum fusiforme is an abundant source of biologically active compounds that are released during fermentation. However, the effects of Lactobacillus fermentation on the nutrient composition of S. fusiforme have yet to be sufficiently determined. In this study, we used five strains of Lactobacillus to ferment S. fusiforme and examined changes in the bioactive components, volatile compounds, and bioactivities of the fermentation supernatants. Among the assessed strains, fermentation with Lactobacillus delbrueckii promoted significant increases in the total phenolic contents, and fermentation with all strains contributed to reductions in the levels of undesirable volatile compounds associated with the characteristic odor of S. fusiforme. In addition, S. fusiforme fermented using L. delbrueckii showed superior ABTS radical scavenging activity, whereas S. fusiforme fermented using L. plantarum FY03 (PF-3) or L. plantarum FY02 (PF-2) showed enhanced DPPH radical scavenging capacity, and fermentation using L. rhamnosus promoted the highest ferric-ion-reducing power. Moreover, the inhibition of α-glucosidase activity increased by 2.0- to 3.0-fold in fermented S. fusiforme, whereas the inhibition of α-amylase activity was only significantly augmented by the PF-2 and PF-3 strains. These findings highlight the potential health benefits of Lactobacillus-fermented S. fusiforme, particularly the enhanced antioxidant activities and the capacity to inhibit α-glucosidase and α-amylase activities.

Four distinct pathways involved in a "tug-of-war" lead to the non-linear nature of phenolic chemistry during lactic acid fermentation of fruits and vegetables

Introduction Lactic acid fermentation of fruits and vegetables (F&V) is endowed with new nutrients and flavors. "Phenolics" is a hot spot in this area, which evolve irregularly during fermentation. However, the mechanism about this non-linear phenomenon has been poorly understood.Objectives This paper was aimed at decoding the mechanism about the non-linear nature of phenolic chemistry during lactic acid fermentation of F&V.Methods Mango and cress slurries were fermented by Lactiplantibacillus plantarum. Different fractions of the slurry samples were analyzed comprehensively. Four pathways relating to phenolic changes were extracted, including adsorption of free phenolics by F&V cell wall materials, microbial adsorption and biotransformation of free phenolics, destabilization of covalent bond between bound phenolics and F&V cell walls. The in-depth features of each pathway during fermentation were explored by multidisciplinary methodologies.Results Throughout both fermentation of mango and cress slurries, free phenolics and the F&V cell wall components undergo dynamic changes. Due to the reduction of pectin fraction in the F&V cell walls during fermentation, the adsorption of free phenolics by F&V cell wall materials through surface diffusion was improved. Also, microbial cells, especially in the latter stages of fermentation, were capable of adsorbing free phenolics through surface diffusion. Moreover, the padC and bglB genes encoding phenolic acid decarboxylase and β-glucosidase were expressed during fermentation, contributing to the conversion of free phenolics. Besides, bound phenolics were not released during fermentation, although its covalent was weakened. The features of the above pathways vary with the fermentation stages and the composition of F&V components, resulting in non-linear changes of free phenolics during F&V fermentation. Conclusion F&V cell wall adsorption, microbial adsorption, microbial biotransformation, and destabilization of the covalent bond of bound phenolics compete in a dynamic "tug-of-war", leading to non-linear nature of phenolic chemistry during F&V fermentation.

Changes in functional activities and volatile flavor compounds of fermented mung beans, cowpeas, and quinoa started with Bacillus amyloliquefaciens SY07

In this work, the functional activities including α-glucosidase, α-amylase, angiotensin converting enzyme (ACE) inhibitory activity, and antioxidant activity of mixed grains (mung beans, cowpeas, and quinoa) fermented with Bacillus amyloliquefaciens SY07 were investigated. The volatile flavor of the mixed grains collected every 12 h during 72 h-fermentation were further detected as well. The inhibition on α-glucosidase and α-amylase reached up to 89.34 % and 50.03 % with the sample concentration of 5.17 and 9.38 mg/mL, respectively. Moreover, the ACE inhibitory activity reached to 93.66 % with the sample concentration of 0.59 mg/mL. The antioxidant capacity of the mixed grains, evaluated by ABTS and DPPH radical scavenging capacities and ferric ion reducing power, was also significantly improved (p < 0.05) during fermentation. The maximum of ABTS and DPPH radical scavenging capacities increased to 8.64 and 3.21 mg TE/g DW, respectively, and the maximum ferric ion reducing power reached to 5.73 mg TE/g DW. Twenty-one volatile flavor compounds with odor activity values (OAVs) ≥ 1 were detected, and six key volatile flavor substances were identified by OPLS-DA analysis, namely, isovaleric acid, acetoin, phenylacetic acid, (Z)-2-nonenol, 1-hexanol, and 1-octen-3-ol, with overall strong creamy, sweet, baked-potato, and cocoa flavors upon fermentation. These findings revealed a favorable pathway for B. amyloliquefaciens SY07 to be used to improve the functional and flavor properties of fermented grains, which would also be of great value for further elucidating the mechanism of the formation of the volatile flavor differences and developing novel quality cereal-based products.

Sprouts as probiotic carriers: A new trend to improve consumer nutrition

Over the past few decades, efforts to eradicate hunger in the world have led to the generation of sustainable development goals to reduce poverty and inequality. It is estimated that the current coronavirus pandemic could add between 83 and 132 million to the total number of undernourished people in the world by 2021. Food insecurity is a contributing factor to the increase in malnutrition, overweight and obesity due to the quality of diets to which people have access. It is therefore necessary to develop functional foods that meet the needs of the population, such as the incorporation of sprouts in their formulation to enhance nutritional quality. Germination of grains and seeds can be used as a low-cost bioprocessing technique that provides higher nutritional value and better bioavailability of nutrients. Consequently, the manuscript describes relevant information about the germination process in different seeds, the changes caused in their nutritional value and the use of techniques within the imbibition phase to modify the metabolic profiles within the sprouts such as inoculation with lactic acid bacteria and yeasts, to generate a functional symbiotic food.

Lactic acid fermentation of guava juice: Evaluation of nutritional and bioactive properties, enzyme (α-amylase, α-glucosidase, and angiotensin-converting enzyme) inhibition abilities, and anti-inflammatory activities

In the present research, the impact of fermentation with two strains of Lactiplantibacillus plantarum subsp. plantarum (PTCC 1896 and PTCC 1745) on physicochemical properties, antioxidant bioactive compounds, and some health-promoting features of guava juice was investigated. Results showed a significant (p < .05) decrease in pH, total soluble solids, glucose and fructose residues, vitamin C, and total carotenoids after 32 h of fermentation. Total phenolic content, free radical scavenging abilities, and ferrous reducing power were markedly enhanced during the fermentation process. Moreover, fermented juice represented good enzyme inhibition abilities (α-amylase and α-glucosidase) and anti-inflammatory activities. The initial amount of angiotensin-converting enzyme inhibitory activity (26.5%) increased to 72.1% and 66.4% in L. plantarum subsp. plantarum 1896 and L. plantarum subsp. plantarum 1745 treatments, respectively. These findings reveal that guava juice fermentation with the studied Lactobacillus strains can be a promising strategy to augment the functional properties of the fruit-based beverage.

Meta-analysis of microbiomes reveals metagenomic features of fermented vegetables

An insightful exploration of the fermented vegetable microbiome is the key to improving food quality and sustainability. Based on 57 fermented vegetable samples from China, Ireland, the UK, and Germany retrieved from public genome databases, we conducted a high-resolution meta-analysis of the fermented vegetable microbiomes. There were significant differences in the microbiota composition and functional pathway diversity of the tested samples, as reflected by the differences in their geographical origins. Metagenomic analysis also revealed the metagenomic features of carbohydrate-active enzymes and antibiotic resistance genes in the fermented vegetable metagenomes. Five putative new species were detected by recovering 221 metagenome-assembled genomes belonging to the genera Rubrobacteraceae, Bifidobacteriaceae, and Ruminococcaceae. Our results provide new ecological insights into the implications of fermented vegetable microbiota composition and functional potential and highlight the importance of high-resolution metagenomic analysis to further investigate the fermented food microbiome.

Impacts of germination and lactic acid bacteria fermentation on anti-nutrients, bioactive compounds, and selected functional properties of industrial hempseed (Cannabis sativa L.)

The impact of fermentation and germination on the metabolite profile and bioactive of 'Cheongsam' hempseed was investigated. The seeds were germinated for 3 days at 26 °C and fermented for 48 h at 37 °C using Pediococcus acidilactici (SRCM201591). The raw (R), fermented seed (RF), sprouts (S), and fermented sprouts (SF) extracts were assessed for anti-nutrients, metabolite profile, and selected bioactivities. Germination and fermentation significantly altered anti-nutrient levels (tannins, saponins, phytic acid, and trypsin inhibitors). They increased total polyphenols, flavonoid contents, and individual polyphenols and cannabinoids. SF demonstrated the highest ABTS (IC50, 291.65 µg/mL) and DPPH (IC50, 345.30 µg/mL) scavenging capacities. However, S (IC50, 73.295 µg/mL) was the most potent anti-inflammatory ingredient. SF (IC50, 74.07 µg/mL) exhibited the most potent alpha-glucosidase inhibition for enzyme inhibitions, while RF (IC50, 63.31 µg/mL) showed the best lipase inhibition potential. The findings demonstrate that germination and fermentation could improve the functional properties of hempseed.

Nutritional, functional, and sensorial properties of oat milk produced by single and combined acid, alkaline, α-amylase, and sprouting treatments

In this study, the effects of different treatments of the oat slurry on the nutritional, functional, and sensorial properties of oat milk were evaluated. The sprouting and sprouting-acidic treatments have the highest oat milk yield (91.70%) and protein extraction yield (82.74%), respectively. The protein concentrations of alkali, sprouting-acidic, and α-amylase-alkali treatments were significantly (p < .05) higher than other treatments. The alkali treatments showed higher fat content (0.66%). In addition, acidic and alkali treatments in single or combined with other treatments showed the highest dry matter and energy value. The carbohydrate content of α-amylase-alkali treatment (4.35%) was higher than other treatments and also, all acidic treatments showed higher ash content (>1) compared to the other treatments. Furthermore, the sprouting-α-amylase and acidic-α-amylase showed the lowest starch (0.28%) and the highest reducing sugar content (3.15%) compared to the other treatments, respectively. Moreover, the α-amylase-alkali treatment showed the highest total phenolic content and antioxidant activity (342.67 mg GAE/L and 183.08 mg BHT eq/L, respectively). Furthermore, sensory evaluation of most treatments showed acceptable scores (≥7) for consumers, especially in the case of α-amylase, sprouting, and α-amylase-sprouting treatments. Results show that the different treatments had different effects on the nutritional, functional, and sensorial properties of oat milk. In conclusion, from the nutritional and functional point of view, the two-stage treatments were more effective than singular treatments on investigated factors proposing their application in functional plant milk preparation.

Influence of Fermentation on Functional Properties and Bioactivities of Different Cowpea Leaf Smoothies during In Vitro Digestion

This study investigated the effects of Lactiplantibacillus plantarum 75 (LAB 75) fermentation at 37 °C for 48 h on the pH, total soluble solids (TSS), colour, total titratable acidity (TTA), carotenoids, and bioactivities of cowpea leaf smoothies from three cultivars (VOP 1, VOP 3, and VOP 4). Fermentation reduced the pH from 6.57 to 5.05 after 48 h. The TTA increased with the fermentation period, whilst the TSS reduced. Fermentation of the smoothies resulted in the least colour changes (∆E) in VOP 1 after 48 h. Fermentation of cowpea smoothies (VOP 1, VOP 3, and VOP 4) improved the antioxidant capacity (FRAP, DPPH, and ABTS), which was attributed to the increase in total phenolic compounds and carotenoid constituents in all of the fermented cowpea smoothies. VOP 1 was further selected for analysis due to its high phenolic content and antioxidant activity. The VOP 1 smoothie fermented for 24 h showed the lowest reduction in TPC (11%) and had the highest antioxidant (FRAP, DPPH, and ABTS) activity. Ltp. plantarum 75 was viable and survived the harsh conditions of the gastrointestinal tract, and, hence, could be used as a probiotic. VOP 1 intestinal digesta showed significantly higher glucose uptake relative to the undigested and the gastric digesta, while the gastric phase had higher levels of α-amylase and α-glucosidase compared to the undigested samples.

Apple polyphenol biotransformation using probiotics in vitro and dynamic simulated digestion by bionic rats

BACKGROUND

The present study investigated the effects of fermentation by Lactobacillus rhamnosus zrx01 (LR-zrx01), Lactobacillus acidophilus zrx02 (LA-zrx02), and Lactobacillus plantarum zrx03 (LP-zrx03), as well as dynamic simulated digestion by bionic rats, on the biotransformation and antioxidant potential of apple polyphenols. Polyphenols were determined by ultra-high-performance liquid chromatography-mass spectrometry, the dynamic simulated digestion of fermented apple pulp was determined by bionic rats, and the antibacterial and antioxidant activities were analyzed.

RESULTS

The polyphenol content of apple pulp fermented using the three strains was respectively 1.41, 1.38, and 1.36 times that of non-fermented pulp. The antibacterial activity of apple pulp improved dramatically after fermentation. Moreover, the antioxidant potential of apple pulp increased after fermentation and digestion. After dynamic simulated digestion by bionic rats, the polyphenol content in unfermented and the three fermented groups increased significantly by 1.19, 1.23, 1.20, and 1.19 times compared to that before digestion, respectively. The major polyphenols in each group with obvious changes were epicatechin, rutin, kaempferol, quercetin-3 galactoside, p-coumaric acid, and two unknown substances, 1 and 2.

CONCLUSION

Fermented and digested apple polyphenols showed better biotransformation effects and mostly existed in the form of small molecules, which was conducive to the improvement of polyphenol bioavailability and beneficial to the absorption of active substances by the human body. These findings build a foundation for the development of functional food beverages. © 2023 Society of Chemical Industry.

Diabetes and seeds: New horizon to promote human nutrition and anti-diabetics compounds in grains by germination

Type 2 diabetes (T2D) is a complex and heterogeneous chronic metabolic disorder disease that is associated with high blood sugar. Because of the side effects of synthetic drugs on T2D patients and their economic burden, interest in plant-derived functional foods like grains with biological activities has developed. Based on scientific reports, whole grains are rich sources of energy, nutrients, and bioactive compounds and are assumed to have beneficial health effects on glucose enzymes regulation or hyperglycemia. Nowadays, different methods have been applied to enhance whole seed healthful properties and anti-diabetic compounds, and germination is one of them. Germination (sprouting) is a cost-effective method for boosting the activity of endogenous seed enzymes and modifying the structure of macromolecules. Some of these macromolecules like bioactive peptides, polyphenols, dietary fiber, and vitamins are related to diabetes management. Determining the best germination condition can help to promote these anti-diabetics properties of compounds. This study presents relevant information about diabetes, the effect of seed germination on releasing bioactive compounds, and optimizing environmental germination conditions to improve the anti-diabetic compounds in seeds for reaching functional food.

Kombucha Reduces Hyperglycemia in Type 2 Diabetes of Mice by Regulating Gut Microbiota and Its Metabolites

Kombucha, which is rich in tea polyphenols and organic acid, is a kind of acidic tea soup beverage fermented by acetic acid bacteria, yeasts, lactic acid bacteria. Kombucha has been reported to possess anti-diabetic activity, but the underlying mechanism was not well understood. In this study, a high-fat, high-sugar diet combined with streptozotocin (STZ) injection was used to induce T2DM model in mice. After four weeks of kombucha intervention, the physiological and biochemical index were measured to determine the diabetes-related indicators. High-throughput sequencing technology was used to analyze the changes in gut microbiota from the feces. The results showed that four weeks of kombucha intervention increased the abundance of SCFAs-producing bacteria and reduced the abundance of gram-negative bacteria and pathogenic bacteria. The improvement in gut microbiota reduced the damage of intestinal barrier, thereby reducing the displacement of lipopolysaccharide (LPS) and inhibiting the occurrence of inflammation and insulin resistance in vivo. In addition, the increased levels of SCFAs-producing bacteria, and thus increasing the SCFAs, improved islet β cell function by promoting the secretion of gastrointestinal hormones (GLP-1/PYY). This study methodically uncovered the hypoglycemic mechanism of kombucha through gut microbiota intervention, and the result suggested that kombucha may be introduced as a new functional drink for T2DM prevention and treatment.

The Effect of Processing on Bioactive Compounds and Nutritional Qualities of Pulses in Meeting the Sustainable Development Goal 2

Diversification of plant-based food sources is necessary to improve global food and nutritional security. Pulses have enormous nutritional and health benefits in preventing malnutrition and chronic diseases while contributing positively to reducing environmental footprint. Pulses are rich in diverse nutritional and non-nutritional constituents which can be classified as bioactive compounds due to their biological effect. These bioactive compounds include but are not limited to proteins, dietary fibres, resistant starch, polyphenols, saponins, lectins, phytic acids, and enzyme inhibitors. While these compounds are of importance in ensuring food and nutritional security, some of the bioactive constituents have ambivalent properties. These properties include having antioxidant, anti-hypertensive and prebiotic effects. Others have a deleterious effect of decreasing the digestibility and/or bioavailability of essential nutrients and are therefore termed antinutritional factors/compounds. Various processing techniques exist to reduce the content of antinutritional factors found in pulses. Traditional processing of pulses comprises soaking, dehulling, milling, germination, fermentation, and boiling, while examples of emerging processing techniques include microwaving, extrusion, and micronization. These processing techniques can be tailored to purpose and pulse type to achieve desired results. Herein, the nutritional qualities and properties of bioactive compounds found in pulses in meeting the sustainable development goals are presented. It also discusses the effect of processing techniques on the nutritional and non-nutritional constituents in pulses as well as the health and environmental benefits of pulse-diet consumption. Major challenges linked to pulses that could limit their potential of being ideal crops in meeting the sustainable development goal 2 agenda are highlighted.

Edible plant Jiaosu: manufacturing, bioactive compounds, potential health benefits, and safety aspects

Edible plant Jiaosu (EPJ), a type of plant-based functional food fermented by beneficial bacteria, has gained publicity in recent years for its potential benefits to health. Important progress in relevant manufacturing technology has been made in the past decade with respect to raw materials, fermentation microorganisms and fermentation conditions. Current research has revealed that EPJ contains abundant nutrients and bioactive compounds, such as minerals, amino acids, polyphenols, organic acids and polysaccharides. Thus, many studies have focused on the beneficial effects of EPJ in preventing lifestyle diseases, such as hyperglycemia, hyperlipidemia, non-alcoholic fatty liver, obesity, diabetes and some cancers, although limited studies have involved the related active compounds and their protective mechanisms. Furthermore, very few studies have investigated the potential safety risks associated with the consumption of such food. In this review, we present a brief summary of the current research progress pertaining to the manufacturing, bioactive compounds, potential health benefits and safety aspects of EPJ. However, as a result of the complex components in EPJ, further studies on the bioactive compounds with relevant beneficial effects in EPJ and the safety evaluations of EPJ consumption are needed. © 2020 Society of Chemical Industry.

Pulses' germination and fermentation: Two bioprocessing against hypertension by releasing ACE inhibitory peptides

Angiotensin-Converting Enzyme (ACE) is one of the main blood pressure regulators in the renin-angiotensin system leading to hypertension. Hypertension is known as the modern world disease which increases the risk of serious human health problems. Synthetic drugs and some natural compounds could treat this disease by binding to ACE and reducing its activity. Pulses, one of the legumes group, that are the rich in protein sources in the human diet, have several bioactive compounds with ACE inhibitory (ACE I) properties. However, several processes need to break down proteins and improve ACE I activity in foods. Germination and fermentation, known by bioprocessing, could make releasing bioactive peptides and polyphenols and exhibit ACE I and either other health properties such as antimicrobial, antioxidant, anti-diabetic and anticancer activities. Various factors such as kind of selective culture, temperature, time and humidity affect these processes. This review summarizes relevant studies about the effect of pulses' germination and fermentation to produce ACE I activity compounds and also explains about main parameters affecting the health properties of these two bioprocessing to treat hypertension that could lead to the development of their application in pharmaceuticals instead of synthetic drugs.

Kefir fermentation as a bioprocess to improve lentils antioxidant properties: is it worthwhile?

Abstract Kefir, a consortium of acetic and lactic bacteria and yeasts, is versatile for biotransformation of vegetable substrates and may improve their bioactive properties. Lentil is a legume rich in vitamins, minerals, complex carbohydrates and proteins, making it an excellent substrate for fermentation and obtaining bioactive molecules. We report the effect of different process variables on antioxidant properties of lentil extracts obtained using kefir as a biotransformation agent and experimental design. The results showed that the factors agitation (rpm) and incubation temperature exerted significant effects. Incubation temperature of 28 °C and agitation of 75 rpm were the most suitable conditions for kefir fermentation and maximizing the antioxidant properties of the fermented lentils. The highest antioxidant activities for fermented products were 4128.39, 35.87 and 23.20 μmol of Trolox equivalents per gram of sample (μmoL TE g-1) measured by Total Antioxidant Capacity, FRAP and DPPH-radical scavenging methods, respectively. Additionally, we detected that the initial fermentation times (in the first six hours) were enough to positively affect the antioxidant properties of the lentil extracts, reaching a percentage increase of up to 270% in the antioxidant activity of the fermented products in relation to those non-fermented samples.

Solid-state fermentation as an efficient strategy for the biotransformation of lentils: enhancing their antioxidant and antidiabetic potentials

Background

Fermentation is a classic industrial process that can be applied as an efficient strategy to increase the release of bioactive compounds with antioxidant and antidiabetic activities.

Methods

This work reported the effects of solid-state fermentation (SSF) performed using strains of Aspergillus oryzae and Aspergillus niger on the antioxidant (DPPH, ABTS and FRAP) and in vitro antidiabetic (inhibition of α-amylase and α-glucosidase activities) potential of lentils.

Results

The results showed that the profiles of the biological activities of the extracts obtained from the fermented samples varied greatly with respect to both the microorganism involved and the fermentation time. The extracts obtained from the fermented lentils by A. oryzae after 72 h and by A. niger after 48 h using the FRAP assay showed the most remarkable changes in the antioxidant activity, increasing by 107 and 81%, respectively, compared to the nonfermented lentils. The lentil extracts produced by fermentation with A. niger after 48 h were able to inhibit the α-glucosidase activity by up to 90%, while a maximal inhibition of amylase (~ 75%) was achieved by the lentil extract obtained after 24 h of fermentation with A. oryzae. The content of the total phenolic compounds (TPCs) and the identification of them in lentil extracts correlated well with the improvement of the biological activities.

Conclusion

These results suggested that SSF was feasible to obtain extracts of fermented lentils with improved antioxidant and antidiabetic properties. Additionally, these results indicated that the proper choice of microorganism is crucial to direct the process for the production of compounds with specific biological activities.

Bioactive Characteristics and Storage of Salt Mixtures Seasoned with Powdered Cereal Sprouts

Sprouting is a process that can improve nutritional and beneficial properties of seeds. This work studies the design of the new healthier product salt seasoned with freeze-dried powdered cereal sprouts. The cereal sprouts mixture (SM), including barley sprouts (BS), oat sprouts (OS), and wheat sprouts (WS), was optimized in terms of total phenolic content (TPh) and antioxidant capacity (AC). The sprouts mixture with optimal features (OSM), composed of 92.9% BS, 0% OS, and 7.1% WS, had 482.82 mg GAE/100 g of polyphenols and 797.97 µmol TE/100 g antioxidant capacity. HPLC analysis showed that the most abundant phenolic compound in OMS was gallic acid (94.27 mg/100 g). OSM was mixed with salt in different ratios (1 : 1, 1 : 2, and 1 : 3) and stored in transparent and amber bottles for six months. Colour, TPh, and AC retention of seasoned salts and OSM was significantly better (p<0.05) preserved in amber bottles during storage, protected from light. The sprout content was in correlation with TPh and AC retention and colour change. These results suggest that cereal sprouts can be used as a safe ingredient for food products such as seasoned salt, adding value to the basic daily diet with no changes in dietary habits.

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

This research was the first to demonstrate the variations of nutritional constituents, glucosidase properties and antioxidant activities in soybeans during different solid state fermentation times (germination → 5 periods for 12 days) with Tricholoma matsutake. Total isoflavones were significantly reduced (2661.54 → 1559.04 μg/g) with the increase of aglycone contents (107.61 → 1285.66 μg/g, 12 times) for fermentation, whereas amino acid and fatty acid slightly increased. Among them, daidzein (43.2 → 43.6 → 421.9 → 721.4 → 634.0 μg/g), genistein (52.7 → 24.4 → 339.5 → 546.6 → 512.8 μg/g) and glutamic acid (0.3 → 1.7 → 3.9 → 6.6 → 16.1 mg/g) markedly increased between germinated and fermented soybeans. Total phenolic contents and antioxidant abilities also considerably increased, especially, ABTS displayed the predominant scavenging capacities (33.1 → 94.8%) at 200 μg/ml, followed by DPPH (11.9 → 87.0%) and hydroxyl (11.2 → 49.2%) radicals. Interestingly, α-glucosidase inhibition (11.8 → 84.9%) and β-glucosidase (3.1 → 40.3 unit/g) exhibited the highest activities after 9 days. Our results implied that fermented soybeans may be contributed to enhance the soybean value in nutrition and biological effect aspects to development of new functional foods.

Antioxidant properties of a vegetable-fruit beverage fermented with two Lactobacillus plantarum strains

Fermented vegetable-fruit beverages are a popular fermented food, with many potential health benefits. In this study, two commercial Lactobacillus plantarum strains were selected to ferment a beverage containing apples, pears, and carrots. The metabolites and antioxidant activities were examined during the fermentation process. Results showed that lactic acid and acetic acid accumulated gradually, whereas malic acid decreased. Glucose and fructose increased from 0.48 and 14.8 g/L to 7.7 and 20.8 g/L, respectively, while sucrose decreased slightly. Ascorbic acid also increased continuously during the fermentation to 90.74 mg/100 mL. DPPH and ABTS radical scavenging activity and FRAP reached their maximum value after 4-8 days. The accumulation of TPC, TFC, and SOD reached their maximum value on the 8th day of fermentation. Our study revealed that the L. plantarum-fermented vegetable-fruit beverage showed significant antioxidant activity, which is helpful in evaluating the fermentation end-point and developing a high-quality fermented beverage.

Comparative Evaluation of the Antioxidant Capacities, Organic Acids, and Volatiles of Papaya Juices Fermented by Lactobacillus acidophilus and Lactobacillus plantarum

Fermentation of foods by lactic acid bacteria is a useful way to improve the nutritional value of foods. In this study, the health-promoting effects of fermented papaya juices by two species, Lactobacillus acidophilus and Lactobacillus plantarum, were determined. Changes in pH, reducing sugar, organic acids, and volatile compounds were determined, and the vitamin C, total phenolic content, and flavonoid and antioxidant capacities during the fermentation process were investigated. Juices fermented by Lactobacillus acidophilus and Lactobacillus plantarum had similar changes in pH and reducing sugar content during the 48 h fermentation period. Large amounts of aroma-associated compounds and organic acids were produced, especially lactic acid, which increased significantly (p<0.05) (543.18 mg/100 mL and 571.29 mg/100 mL, resp.), improving the quality of the beverage. In contrast, the production of four antioxidant capacities in the fermented papaya juices showed different trends after 48 hours’ fermentation by two bacteria. Lactobacillus plantarum generated better antioxidant activities compared to Lactobacillus acidophilus after 48 h of fermentation. These results indicate that fermentation of papaya juice can improve its utilization and nutritional effect.

Rapid characterization of metabolites in soybean using ultra high performance liquid chromatography coupled with electrospray ionization quadrupole time-of-flight mass spectrometry (UPLC-ESI-Q-TOF-MS/MS) and screening for α-glucosidase inhibitory and antioxidant properties through different solvent systems

This work was the first to investigate on the simultaneous characterization of metabolite profiles in soybean using UPLC-ESI-Q-TOF-MS/MS. Twenty two compositions were observed within 14 min from the methanol extract and confirmed as twelve isoflavones of three types and ten soyasaponins (Ab, Af, I-III, αg, βg, βa, γg, and γa). Moreover, the patterns of two chemicals showed considerable differences in seven solvent systems by HPLC analysis and their optimal extraction was achieved by 70% methanol (isoflavone: 4102.69 μg/g; soyasaponin: ten peaks). The second abundant isoflavones were detected in 50% methanol (4054.39 μg/g), followed by 30% methanol, 100% methanol, 10% methanol, CH2Cl2, and acetone extracts with 3134.03, 2979.49, 1681.33, 366.19, and 119.00 μg/g, respectively. Soyasaponins exhibited similar tendencies as those of isoflavones. The highest total phenolic was found as 2.10 ± 0.05 mg GAE/g in 70% methanol with remarkable differences by comparing other extracts. Specifically, this extract showed potent α-glucosidase inhibitory (81%) and antioxidant capacities (DPPH: 93% and ABTS: 95%) at a concentration of 1.0 mg/mL. Our results may be contributed to enhancing the value to functional foods and evaluating the secondary metabolites concern to antioxidant properties using solvent system in soybean.