Bioactive Isoflavone Aglycones Research Articles

Fermented soy beverages as vehicle of probiotic lactobacilli strains and source of bioactive isoflavones: A potential double functional effect

Soy beverages can be a source of bioactive isoflavones, with potential human health benefits. In this work, the suitability of three Lacticaseibacillus and three Bifidobacterium probiotic strains as functional starters for soy beverage fermentation were evaluated, alongside with the effect of refrigerated storage on the viability of the strains and the isoflavone composition of the fermented beverages. The three bifidobacteria strains suffered a decrease in their viability during refrigeration and only Bifidobacterium breve INIA P734 produced high concentrations of bioactive isoflavones. Meanwhile, L. rhamnosus GG and L. rhamnosus INIA P344 produced high levels of aglycones and, with L. paracasei INIA P272, maintained their viability during the refrigeration period, constituting promising starters to obtain functional soy beverages that could gather the benefits of the bioactive isoflavone aglycones and the probiotic strains. Moreover, the three lactobacilli caused an increase in the antioxidant capacity of the fermented beverages, which was maintained over the refrigerated storage.

Soy fermentation by orally isolated putative probiotic Streptococcus salivarius for healthy oral

Aim: Consumption of aglycones-rich fermented soy has been positively associated with the recuperation of systemic inflammation. As oral conditions have an impact on overall health and diseases, the reestablishment of bacteria particularly by indigenous oral probiotic is believed to be able to reverse oral inflammation by antagonize oral pathogen and thus maintaining good oral health. Streptococcus salivarius can be combined with bioactive isoflavone aglycones to further improve oral healthiness. This study aimed to explore decent advantages by indigenous source of Streptococcus isolated from healthy periodontal to ferment soy while maintaining probiotic properties before delivering in product targeting oral health. Materials and Methods: Putative probiotic properties of isolated strains were explored through antibiotic susceptibility ensuring safe strain consumption. S. salivarius from Taylor’s University Culture Collection (TUCC) 1254 was selected for probiotic properties evaluation, in comparison with the type strain. Both strains were evaluated for fermentation ability in soy through growth, β-glucosidase assay, and isoflavone bioconversion. Results: The antagonistic ability of S. salivarius TUCC 1254 was better under anaerobic than microaerobic condition; the strain also showed higher colonizing ability to epithelial tissue than the tooth surface resemblance. The strain showed vast cell growth accompanied by organic acid production and higher β-glucosidase enzyme to bioconvert isoflavone glucosides to bioactive aglycones that could reduce oral inflammation than K12. Soy improved auto-aggregation ability of S. salivarius, which could promote biofilm formation and thus could achieve enhanced oral pathogen-eradicating intention. Conclusion: This study suggested that indigenous bacteria could serve as a better source of oral probiotics and coupling with fermented soy bioactive isoflavone aglycones, become a deliverable platform for improving oral health.

Optimization and kinetics modeling of okara isoflavones extraction using subcritical water

In this study, the soybean milk and tofu byproduct okara was subjected to subcritical water extraction with the intention of recovering isoflavones with minimal degradation. Response Surface Methodology (RSM) of the extraction variables indicated that optimized conditions would be T = 146.23 °C, P = 3.98 MPa, and α = 20 mg (solid)/mL (extractant). Mathematical models for the conversion and degradation of isoflavones were solved as a set of simultaneous equations leading to rate constants and time-dependent concentration profiles for each genistein- and daidzein-based compound. These kinetic analyses suggested that an optimum extraction time, under RSM-optimized conditions, would be 213.5 ± 8.7 min. The results of our study suggest that okara byproducts could be valorized efficiently, as a source of bioactive isoflavone aglycones, using subcritical water. The mathematical models and optimized extraction conditions that we established in this study could be employed, as process control-optimized variables, in the exploitation of okara, specifically in the isolation of genistein and daidzein.

Optimization of lactic acid fermentation conditions for fermented tofu whey beverage with high-isoflavone aglycones

Four lactic acid bacteria strains (Lactobacillus paracasei, Leuconostoc mesenteroides, Lactobacillus rhamnosus GG and Lactobacillus plantarum), possessing β-glucosidase enzyme activity, were investigated for tofu whey fermentation based on the capacity of bioconversion of isoflavones. The results suggested that the mixture of L. rhamnosus GG and L. paracasei had great potential for efficient enrichment of bioactive isoflavone aglycones and the percentage composition (daidzein, genistein) increased from 4.6 to 93.78% after fermentation of tofu whey. At the same time, the viable cell counts of the mixture of L. rhamnosus GG and L. paracasei increased to 9.13 log10 CFU/mL while pH value dropped to 4.48 and titratable acidity was 0.28%. Headspace solid-phase microextraction method followed by gas chromatography-mass spectrometry analysis indicated that the odor compounds, particularly the aldehydes and alcohols, were metabolized to trace or undetected levels after fermentation. This research provided not only a new way to develop a functional probiotic beverage enriched in isoflavone aglycones, but also provided a potentially valuable new use for soy whey protein.

Endophytic Streptomyces sp. AC35, a producer of bioactive isoflavone aglycones and antimycins.

In this research, a microbial endophytic strain obtained from the rhizosphere of the conifer Taxus baccata and designated as Streptomyces sp. AC35 (FJ001754.1 Streptomyces, GenBank) was investigated. High 16S rDNA gene sequence similarity suggests that this strain is closely related to S. odorifer. The major fatty acid profile of intracellular lipids was also carried out to further identify this strain. Atomic force microscopy and scanning acoustic microscopy were used to image our strain. Its major excreted substances were extracted, evaluated for antimicrobial activity, purified, and identified by ultraviolet-visible spectroscopy (UV-vis), liquid chromatography-mass spectrometry (LC-MS/MS) and nuclear magnetic resonance as the bioactive isoflavone aglycones-daidzein, glycitein and genistein. Batch cultivation, performed under different pH conditions, revealed enhanced production of antimycin components when the pH was stable at 7.0. Antimycins were detected by HPLC and identified by UV-vis and LC-MS/MS combined with the multiple reaction monitoring. Our results demonstrate that Streptomyces sp. AC35 might be used as a potential source of effective, pharmaceutically active compounds.

Effect of electroporation on bioconversion of isoflavones and probiotic properties of parents and subsequent passages of Bifidobacterium longum.

This study aimed to evaluate the effects of electroporation on growth, bioconversion of isoflavones, and probiotic properties of parent organisms and subsequent passages of Bifidobacterium longum FTDC 8643. Electroporation with the strength of electric field at 7.5kVcm(-1) for 3.5ms was applied on B. longum FTDC 8643. The viability of B. longum FTDC 8643 increased significantly upon treatment with electroporation. Such treatment also enhanced the intracellular and extracellular β-glucosidase activity, leading to enhanced production of bioactive isoflavone aglycones in mannitol-soymilk (P < 0.05). In addition, these treated cells also exhibited better tolerance toward acidic (pH2 and pH3) and intestinal bile salt condition compared to the control (P < 0.05). The electroporated cell also possessed better adhesion ability and antimicrobial activity (P < 0.05). However, all these positive effects were only prevalent in the parent cells and were not observed in their subsequent passages of electroporated cells. Our results suggested that electroporation could enhance the bioactive and probiotic potentials of parent cells of B. longum FTDC 8643 and could be used in the production of probiotic foods with enhanced bioactivity.

ACE inhibitory activity and bioconversion of isoflavones by Lactobacillus in soymilk supplemented with B‐vitamins

PurposeThe aim of this study is to examine the bioactive properties of lactobacilli‐fermented B‐vitamin soymilk, namely the in‐vitro antihypertensive property and bioconversion of isoflavone glucosides to aglycones.Design/methodology/approachLactobacillus acidophilus BT 1088, L. fermentum BT 8219, L. acidophilus FTDC 8633 and L. gasseri FTDC 8131 were investigated for their bioactive potential and enhanced bioconversion of isoflavones in soymilk supplemented with individual B‐vitamins at a concentration of 1 mg/L.FindingsThe supplementation of thiamine, riboflavin, niacinamide, calcium pantothenate, biotin and folic acid enhanced the ACE‐inhibitory activity of lactobacilli in soymilk accompanied by a lower IC50 value compared to the control (P&lt;0.05). The β‐glucosidase specific activity of lactobacilli was also enhanced on supplementation of B‐vitamins, leading to increased bioconversion of isoflavones in soymilk. The concentration of genistein was decreased, accompanied by an increased concentration of genistein on fermentation in the presence of thiamine, niacinamide, biotin, calcium pantothenate and folic acid. Additionally, the supplementation of niacinamide, calcium pantothenate, biotin and folic acid also led to lower concentrations of malonyl daidzin, indicating increased hydrolysis of malonyl daidzin to daidzin. Results from the present study indicated that the supplementation of B‐vitamins could enhance the bioactive potential and bioconversion of isoflavones in lactobacilli‐fermented soymilk.Originality/valueThis work has shown that the supplementation of B‐vitamins in lactobacilli fermented soymilk has exerted in vitro ACE‐inhibitory activity and increased the accumulation of bioactive isoflavone aglycones. To the authors' knowledge, this is the first evaluation reporting on such aspects.

Enhancing the Biotransformation of Isoflavones in Soymilk Supplemented with Lactose Using Probiotic Bacteria during Extended Fermentation

Soymilk (SM) lacks lactose; hence supplementation of SM with lactose is likely to enhance the growth of probiotic bacteria and biotransformation of isoflavone glycosides to isoflavone aglycones. In this study, 11 strains of probiotic bacteria including Lactobacillus rhamnosus, L. salivarius, L. plantarum, L. acidophilus, L. paracasei, HOWARU L. rhamnosus, L. delbrueckii subsp. bulgaricus, Bifidobacterium lactis type Bi-07, B. longum, HOWARU B. bifidum, and B lactis type Bi-04 were inoculated individually or as mixed cultures into SM and soymilk supplemented with lactose (SML). A total of 2% of lactose was added to 1 L of SM with the aim of improving the growth of probiotic organisms and promoting the biotransformation of isoflavone isomers to bioactive isoflavone aglycomes. Samples of SM were incubated at 37 degrees C and 10 mL aliquots of SM were taken at 0, 24, 48, and 72 h to monitor the growth of probiotic bacteria and changes in isoflavone contents using high-performance liquid chromatography (HPLC). Results indicated that SML fermented with probiotics had higher viable counts by >2.4 log CFU/mL than that in SM at the end of the 72 h fermentation period. Mixed cultures grew at different rates and in general Lactobacilius spp. had >1.02 log CFU/mL more cells than Bifidobacterium spp. at the end of the fermentation period. The total aglycone content in SM at 72 h of fermentation was 0.924 mg/100 mL, whereas that in SML was 1.623 mg/100 mL. Addition of lactose not only improved the growth of probiotic bacteria in SM but also enhanced the biotransformation of isoflavone glucosides to the more bioactive isoflavone aglycones. Mixed cultures did not improve the biotransformation of bioactive isoflavones when compared to single cultures.

Analysis of bioactive aglycone isoflavones in soybean and soybean products

PurposeThe purpose of this paper is to investigate isoflavone aglycone concentrations in commercial soybean and soybean products in Taiwan.Design/methodology/approachIsoflavone concentration was determined by high performance liquid chromatography method. The samples included soybeans, non‐fermented (tofu, soymilk, soybean meal) and fermented (natto, miso and sufu) soybean products.FindingsThe total isoflavone concentration in soybean and soybean products was approximately 109‐508 mg/100 g. Isoflavone aglycones had the concentration of 2‐19 per cent of total isoflavones in soybeans and non‐fermented soybean products. There was a broad diversity of isoflavone aglycones at 4‐94 per cent of total isoflavones in fermented soybeans.Originality/valueThe study provides new information about distribution of bioactive isoflavone aglycones in soybean and soybean products. Isoflavone glucosides were the major components in all soybean and non‐fermented products, while isoflavone aglycones were abundant in sufu and partially in miso of soybean fermented products. The information should be used to establish that positive consumption of bioactive aglycones isoflavones may be more efficient for improving the physiological functions for human health.

Sensory properties of soy yoghurts prepared from yellow and black soymilk using Streptococcus infantarius 12 and Weisellia sp. 4

AbstractBACKGROUND: Soy yoghurts containing enhanced bioactive isoflavone aglycones were prepared from combinations of yellow (YS) and black soymilk (BS) (YS:BS = 100:0, 70:30, 50:50 and 0:100, v/v) by fermentation with Streptococcus infantarius 12 and Weisellia sp. 4 at 37 °C for 10 h. Sensory properties of the bioactive soy yoghurts were investigated. Furthermore, other characteristics including the contents of isoflavones, viable cell numbers, pH, colour and DPPH radical scavenging activity were investigated.RESULTS: One hundred percent YS yoghurt showed the highest scores of all sensory attributes while 100% BS yoghurt was the lowest for colour and smoothness. The overall acceptability scores were 5.9 and 5.2 for 100% YS and 100% BS yoghurts, respectively (9‐point scale). The L‐values of soy yoghurts decreased as the percentage BS increased, indicating darkening of soy yoghurts. The contents of bioactive isoflavone aglycones (daidzein and genistein) in soy yoghurts remarkably increased (&gt;1300 mg kg−1) by fermentation. Viable cell numbers and pH of soy yoghurts ranged from 8.4 × 108 to 9.6 × 108 CFU g−1 and 4.43 to 4.54, respectively. DPPH radical scavenging activity significantly increased as the percentage BS increased (P &lt; 0.05).CONCLUSION: One hundred percent YS yoghurt was better for overall sensory properties while 100% BS yogurt was more bioactive in terms of the isoflavone aglycone contents and DPPH radical scavenging activity compared to other yoghurts. Copyright © 2008 Society of Chemical Industry

Fermentation of Calcium‐Fortified Soymilk with Lactobacillus: Effects on Calcium Solubility, Isoflavone Conversion, and Production of Organic Acids

The objective of this study was to enhance calcium solubility and bioavailability from calcium-fortified soymilk by fermentation with 7 strains of Lactobacillus, namely, L. acidophilus ATCC 4962, ATCC33200, ATCC 4356, ATCC 4461, L. casei ASCC 290, L. plantarum ASCC 276, and L. fermentum VRI-003. The parameters that were used are viability, pH, calcium solubility, organic acid, and biologically active isoflavone aglycone content. Calcium-fortified soymilk made from soy protein isolate was inoculated with these probiotic strains, incubated for 24 h at 37 degrees C, then stored for 14 d at 4 degrees C. Soluble calcium was measured using atomic absorption spectrophotometry (AA). Organic acids and bioactive isoflavone aglycones, including diadzein, genistein, and glycetein, were measured using HPLC. Viability of the strains in the fermented calcium-fortified soymilk was > 8.5 log(10) CFU/g after 24 h fermentation and this was maintained for 14-d storage at 4 degrees C. After 24 h, there was a significant increase (P < 0.05) in soluble calcium. L. acidophilus ATCC 4962 and L. casei ASCC 290 demonstrated the highest increase with 89.3% and 87.0% soluble calcium after 24 h, respectively. The increase in calcium solubility observed was related to lowered pH associated with production of lactic and acetic acids. Fermentation significantly increased (P < 0.05) the level of conversion of isoflavones into biologically active aglycones, including diadzein, genistein, and glycetein. Our results show that fermenting calcium-fortified soymilk with the selected probiotics can potentially enhance the calcium bioavailability of calcium-fortified soymilk due to increased calcium solubility and bioactive isoflavone aglycone enrichment.

Stability of isoflavone phytoestrogens in fermented soymilk with Bifidobacterium animalis Bb12 during storage at different temperatures

SummarySoy isoflavones in fermented soymilk with Bifidobacterium animalis Bb12 were stored at various temperatures (−80, 4, 24.8 and 37 °C) for 8 weeks and the concentration of isoflavones determined weekly using reverse‐phase high‐performance liquid chromatography (RP‐HPLC). The first‐order kinetic model was used to assess the degradation of each isomer at each storage temperature. Soymilk predominantly possesses high concentrations of isoflavone glucosides and very low concentration of bioactive aglycone component. During storage at various temperatures, concentrations of individual isoflavone isomers appeared to be significantly stable (P &lt; 0.01). Interestingly, aglycones showed much smaller degradation constants compared with glucosides at all the storage temperatures studied. Genistein and daidzein were much more stable than glycitein and had almost similar degradation patterns, despite differences in their concentrations in the fermented soymilk. It was, however, observed that 4 °C was the most suitable storage temperature for the product in order to guarantee minimal degradation of bioactive isoflavone aglycones.