Isoflavone Glycosides (isoflavone + glycoside)

Distribution by Scientific Domains


Selected Abstracts


HYDROLYSIS OF ISOFLAVONE GLYCOSIDES IN SOY MILK BY ,-GALACTOSIDASE AND ,-GLUCOSIDASE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2009
THUY T. PHAM
ABSTRACT The objective of this study was to assess the potential of pure ,-galactosidase and ,-glucosidase for hydrolyzing isoflavone glycosides to aglycones in soy milk. Both pure ,-galactosidase and ,-glucosidase were added at various concentrations (0.5, 1.0, 2.0 and 4.0 U/mL) to soy milk made from 4% soy protein isolate and incubated at 37C for up to 240 min. Isoflavones were quantified using high-performance liquid chromatography. The isoflavone contents of soy milk before and after autoclaving were also compared. ,-Glucosidase and ,-galactosidase were both able to hydrolyze the ,-glucosidic linkages in isoflavone glycosides. A range of 43.3 to 77.2% of the total isoflavone glycosides was hydrolyzed at various ,-galactosidase concentrations. The ,-glucosidase hydrolyzed isoflavone glycosides more efficiently than ,-galactosidase. At the most diluted ,-glucosidase concentration (0.5 U/mL), 86.6% of isoflavone glycosides were hydrolyzed to aglycones at 240 min. PRACTICAL APPLICATIONS Isoflavone glycosides, which are mainly found in the bean family, are the inactive forms of isoflavones. However, aglycones, which are the nonsugar component of a glycoside molecule that results from hydrolysis of the isoflavone glycosides, are the biologically active forms. Because of their similarity to female hormone, they are considered a "natural way" to relieve the menopausal symptoms as they prevent certain cancers and improve bone health. Only a small amount of the total isoflavones, however, exists in the aglycone forms in nature. A novel method to produce aglycones from natural isoflavones is highly important. ,-Glucosidase has been claimed to be the only enzyme which is able to hydrolyze isoflavone glycosides to aglycones. However, other enzymes could hydrolyze isoflavone glycosides more efficiently and could be easier to produce. This paper investigates the ability of ,-galactosidase to biotransform isoflavone glycosides to aglycones, as the source of the enzyme is abundant. [source]


Effect of Lactulose on Biotransformation of Isoflavone Glycosides to Aglycones in Soymilk by Lactobacilli

JOURNAL OF FOOD SCIENCE, Issue 3 2008
T.T. Pham
ABSTRACT:,Lactobacillus acidophilus 4461, L. acidophilus 4962, L. casei 290, and L. casei 2607 were used to hydrolyze isoflavone glycosides (IG) to biologically active forms,isoflavone aglycones (IA),in soymilk (SM) prepared from soy protein isolate (SPI) and soymilk supplemented with 0.5% (w/v) of lactulose (SML). L. acidophilus 4461 utilized the highest level of lactulose (3.01 mg/mL) and L. acidophilus 4962 utilized the least (0.86 mg/mL) at 24 h of incubation. The pH values decreased to 4.00 to 5.00 in SML, while they remained relatively high (6.15 to 6.36) in SM. Supplementation with lactulose significantly (P < 0.05) enhanced the viable counts of all the 4 Lactobacillus strains. At the end of incubation, the viable counts of Lactobacillus ranged from 8.08 to 8.25 log CFU/mL in SML compared to 6.99 to 7.11 log CFU/mL in SM. Supplementation with lactulose increased the biotransformation of IG to IA after 6 h of incubation. The presence of lactulose in the medium enhanced the biotransformation level of IG to IA by Lactobacillus up to 21.9%. The hydrolysis level of malonyl genistin and acetyl genistin in SML was much higher than in SM by all the 4 probiotic organisms. The biotransformation of IG to IA occurred rapidly during the 1st 12 h of incubation in both SML and SM. Among the 4 Lactobacillus strains, L. acidophilus 4461 biotransformed the highest level (88.8%) of IG to IA in SML compared to 68.2% in SM after 24 h of incubation. [source]


Biotransformation of Isoflavone Glycosides by Bifidobacterium animalis in Soymilk Supplemented with Skim Milk Powder

JOURNAL OF FOOD SCIENCE, Issue 8 2007
T.T. Pham
ABSTRACT:, Two probiotic strains, Bifidobacterium animalis A and B, were used for the biotransformation of isoflavone glycosides in soymilk prepared from soy protein isolate (SPI) supplemented with skim milk powder (SMP) (SSMP). Unsupplemented soymilk (USM) and reconstituted skim milk powder (RSMP) were used as controls. The numbers of viable microorganisms in these products were enumerated. Lactose and isoflavone contents were quantified using high-performance liquid chromatography (HPLC). Our results showed that there was significantly higher biotransformation of isoflavone glycosides to aglycones in SSMP than that in USM. The levels of biotransformation were 83.96% and 85.43% for B. animalis A and B, respectively, compared to 74.30% and 72.82% for the USM. In addition, lactose utilization by both strains in SSMP was also higher than that in RSMP. At 24 h, 21.16 mg/mL of lactose was utilized in SSMP by B. animalis A compared with that of 16.88 mg/mL in RSMP. Consequently, the pH of SSMP was lower (3.80) than RSMP (4.00). However, the number of viable bacteria in SSMP was slightly lower than that in RSMP but significantly higher than that in USM. It appears that SMP enhanced the biotransformation of isoflavone glycosides to aglycones and SPI increased the lactose utilization by B. animalis A and B. [source]


Conversion of Isoflavone Glycosides to Aglycones in SoyLife and Soymeal Using ,-glycosidase

JOURNAL OF FOOD SCIENCE, Issue 2 2003
L. Xie
ABSTRACT: Conversion of isoflavones from glycosides to aglycones in SoyLife and soymeal using varying concentrations of ,-glycosidase, and different pH conditions and temperatures was investigated. The best conditions for the conversion of glycosides to aglycones were pH 5.0, 50 °C, and 5 h incubation with 5 units ,-glycosidase/g Soy Life and 1.5 units/g soymeal. Under these conditions, the amount of genistein, daidzein, and glycitein in Soy Life treated with ,-glycosidase were 4.22, 11.52, and 11.85 ,mol/g compared to untreated controls of 0.26, 0.97, and 4.43 ,mol/g, respectively. In soymeal, the amounts were 3.21, 2.02, and 2.12 ,mol/g compared to untreated controls of 1.23, 1.25, and 1.51 ,mol/g, respectively. Mole percent recovery of genistein was 87% in Soy Life and 80% in soymeal, respectively. [source]


HYDROLYSIS OF ISOFLAVONE GLYCOSIDES IN SOY MILK BY ,-GALACTOSIDASE AND ,-GLUCOSIDASE

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2009
THUY T. PHAM
ABSTRACT The objective of this study was to assess the potential of pure ,-galactosidase and ,-glucosidase for hydrolyzing isoflavone glycosides to aglycones in soy milk. Both pure ,-galactosidase and ,-glucosidase were added at various concentrations (0.5, 1.0, 2.0 and 4.0 U/mL) to soy milk made from 4% soy protein isolate and incubated at 37C for up to 240 min. Isoflavones were quantified using high-performance liquid chromatography. The isoflavone contents of soy milk before and after autoclaving were also compared. ,-Glucosidase and ,-galactosidase were both able to hydrolyze the ,-glucosidic linkages in isoflavone glycosides. A range of 43.3 to 77.2% of the total isoflavone glycosides was hydrolyzed at various ,-galactosidase concentrations. The ,-glucosidase hydrolyzed isoflavone glycosides more efficiently than ,-galactosidase. At the most diluted ,-glucosidase concentration (0.5 U/mL), 86.6% of isoflavone glycosides were hydrolyzed to aglycones at 240 min. PRACTICAL APPLICATIONS Isoflavone glycosides, which are mainly found in the bean family, are the inactive forms of isoflavones. However, aglycones, which are the nonsugar component of a glycoside molecule that results from hydrolysis of the isoflavone glycosides, are the biologically active forms. Because of their similarity to female hormone, they are considered a "natural way" to relieve the menopausal symptoms as they prevent certain cancers and improve bone health. Only a small amount of the total isoflavones, however, exists in the aglycone forms in nature. A novel method to produce aglycones from natural isoflavones is highly important. ,-Glucosidase has been claimed to be the only enzyme which is able to hydrolyze isoflavone glycosides to aglycones. However, other enzymes could hydrolyze isoflavone glycosides more efficiently and could be easier to produce. This paper investigates the ability of ,-galactosidase to biotransform isoflavone glycosides to aglycones, as the source of the enzyme is abundant. [source]


Effect of Lactulose on Biotransformation of Isoflavone Glycosides to Aglycones in Soymilk by Lactobacilli

JOURNAL OF FOOD SCIENCE, Issue 3 2008
T.T. Pham
ABSTRACT:,Lactobacillus acidophilus 4461, L. acidophilus 4962, L. casei 290, and L. casei 2607 were used to hydrolyze isoflavone glycosides (IG) to biologically active forms,isoflavone aglycones (IA),in soymilk (SM) prepared from soy protein isolate (SPI) and soymilk supplemented with 0.5% (w/v) of lactulose (SML). L. acidophilus 4461 utilized the highest level of lactulose (3.01 mg/mL) and L. acidophilus 4962 utilized the least (0.86 mg/mL) at 24 h of incubation. The pH values decreased to 4.00 to 5.00 in SML, while they remained relatively high (6.15 to 6.36) in SM. Supplementation with lactulose significantly (P < 0.05) enhanced the viable counts of all the 4 Lactobacillus strains. At the end of incubation, the viable counts of Lactobacillus ranged from 8.08 to 8.25 log CFU/mL in SML compared to 6.99 to 7.11 log CFU/mL in SM. Supplementation with lactulose increased the biotransformation of IG to IA after 6 h of incubation. The presence of lactulose in the medium enhanced the biotransformation level of IG to IA by Lactobacillus up to 21.9%. The hydrolysis level of malonyl genistin and acetyl genistin in SML was much higher than in SM by all the 4 probiotic organisms. The biotransformation of IG to IA occurred rapidly during the 1st 12 h of incubation in both SML and SM. Among the 4 Lactobacillus strains, L. acidophilus 4461 biotransformed the highest level (88.8%) of IG to IA in SML compared to 68.2% in SM after 24 h of incubation. [source]


Production of ,-Glucosidase and Hydrolysis of Isoflavone Phytoestrogens by Lactobacillus acidophilus, Bifidobacterium lactis, and Lactobacillus casei in Soymilk

JOURNAL OF FOOD SCIENCE, Issue 1 2008
O.N. Donkor
ABSTRACT:, The study determined ,-glucosidase activity of commercial probiotic organisms for hydrolysis of isoflavone to aglycones in fermenting soymilk. Soymilk made with soy protein isolate (SPI) was fermented with Lactobacillus acidophilus LAFTIŽ L10, Bifidobacterium lactis LAFTIŽ B94, and Lactobacillus casei LAFTIŽ L26 at 37 °C for 48 h and the fermented soymilk was stored for 28 d at 4 °C. ,-Glucosidase activity of organisms was determined using ,-nitrophenyl ,-D-glucopyranoside as a substrate and the hydrolysis of isoflavone glycosides to aglycones by these organisms was carried out. The highest level of growth occurred at 12 h for L. casei L26, 24 h for B. lactis B94, and 36 h for L. acidophilus L10 during fermentation in soymilk. Survival after storage at 4 °C for 28 d was 20%, 15%, and 11% greater (P < 0.05) than initial cell counts, respectively. All the bacteria produced ,-glucosidase, which hydrolyzed isoflavone ,-glycosides to isoflavone aglycones. The decrease in the concentration of ,-glycosides and the increase in the concentration of aglycones were significant (P < 0.05) in the fermented soymilk. Increased isoflavone aglycone content in fermented soymilk is likely to improve the biological functionality of soymilk. [source]


Biotransformation of Isoflavone Glycosides by Bifidobacterium animalis in Soymilk Supplemented with Skim Milk Powder

JOURNAL OF FOOD SCIENCE, Issue 8 2007
T.T. Pham
ABSTRACT:, Two probiotic strains, Bifidobacterium animalis A and B, were used for the biotransformation of isoflavone glycosides in soymilk prepared from soy protein isolate (SPI) supplemented with skim milk powder (SMP) (SSMP). Unsupplemented soymilk (USM) and reconstituted skim milk powder (RSMP) were used as controls. The numbers of viable microorganisms in these products were enumerated. Lactose and isoflavone contents were quantified using high-performance liquid chromatography (HPLC). Our results showed that there was significantly higher biotransformation of isoflavone glycosides to aglycones in SSMP than that in USM. The levels of biotransformation were 83.96% and 85.43% for B. animalis A and B, respectively, compared to 74.30% and 72.82% for the USM. In addition, lactose utilization by both strains in SSMP was also higher than that in RSMP. At 24 h, 21.16 mg/mL of lactose was utilized in SSMP by B. animalis A compared with that of 16.88 mg/mL in RSMP. Consequently, the pH of SSMP was lower (3.80) than RSMP (4.00). However, the number of viable bacteria in SSMP was slightly lower than that in RSMP but significantly higher than that in USM. It appears that SMP enhanced the biotransformation of isoflavone glycosides to aglycones and SPI increased the lactose utilization by B. animalis A and B. [source]