• KSBB Journal
• /
• v.16 no.2
• /
• pp.174-178
• /
• 2001

Soybeans contain the phytoestrogens genistein and daidzein, their glucosides genistin and daidzin and coumesterol. These isoflavonoid compounds are capable of producing an estrogenic response in a number of diverse species. This study determined optimum conditions for the extraction of the main isoflavones(daidzin, genistin, daidzein, genistein) in defatted soybean meal using high-performance liquid chromatography. The best optimum extraction was achieved at 75% ethanol, $80^{circ}C$, pH4 and a three hour contact time. In addition, isoflavones with high purity were separated by adding up to 4%(w/v) of calcium chloride dihydrate. Most soybean extracts were composed of $beta$-glucosidic conjugate(daidzin, genistin) which is difficult to adsorb in body. Therefore, $beta$-glucosidase was used to convert as conjugate to aglycone form (daidzein, genistein) which is easy to adsorb. The optimal conditions of enzyme reaction involved to be 8.4 units of enzyme concentration, pH5.0, $40^{circ}C$ and 40 minutes.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.65 no.2
• /
• pp.84-92
• /
• 2020

For humans, soybean and soybean products are the main dietary sources of isoflvones, which are polyphenolic compounds that represent one of the most common categories of phytoestrogens. The objective of this study was to determine isoflavone concentrations in soybean cultivars during germination when treated with some biotic substances. Three soybean cultivars were germinated in replicated trials in 2018/2019 and their individual and total isoflavone concentrations were determined using HPLC (High-Performance Liquid Chromatography). Significant differences were observed in total isoflavone content were observed among cultivars regardless of years and treatments. 'Daepung2-ho' and 'Uram' had significantly higher total isoflavones than 'Pungsannaul-kong'. Differences among treatments were also significant for total isoflavone content. In 2018, with chitosan treatment, total isoflavone concentration ranged from 551.15 to 7584.07 ㎍ g^-1, with an average of 2972.64 ㎍ g^-1 across cultivars. In 2019, there was no significant difference among treatments in total isoflavone content. Regarding individual isoflavone concentrations, the malonyl-glucoside groups accounted for over 85% of the total isoflavone content, which is indicated that these groups play an important role with regard to isoflavone components in soybean seeds. The individual proportions in the total concentrations of isoflavones varied according to germination period and seed tissues. Glucosides and malonyl-glucosides showed differences in concentrations among seed tissues, aglycones were further accumulated as germination period was progressed. This study suggests that biotic substances have an impact on seed isoflavone content during germination. However, cultivars with consistently high or low isoflavone concentrations across biotic substance treatments were identified desspite differences in germination period and seed tissues, demonstrating that the genetic factor plays the most important role in isoflavone accumulation.

• Food Engineering Progress
• /
• v.23 no.3
• /
• pp.209-216
• /
• 2019

The effects of fermentation on soy embryo have been investigated using lactic acid bacteria, Lactobacillus acidophilus (LA), Lactobacillus bulgaricus (LB), Streptococcus thermophilussei (ST), and Lactobacillus plantarum (LP). As a result of the fermentation test of the isoflavone conversion by strain type, inoculation content, and fermentation time, the optimum conditions were LP bacterium, an inoculum amount of 5%, and a fermentation time of 24 hours. The composition of the isoflavone glycosides in the control was the highest in the order of glycitin> daidzin> genistin. When fermented with lactic acid bacteria, glycoside content decreased, and aglycone content increased. The order of composition was daidzein>glycitein>genistein. In the fermentation with LP bacterium, soyasaponin Ab content decreased and Ba and Bb content increased. Upon assessing the result of the experiment, it was found that the pH of the fermentation broth had a great influence in the bioconversion of isoflavone and soyasaponin. In the case of fermentation by pH 6 broth, aglycone and Bb content was the highest. The increase of aglycone content by fermentation reaction with the LP bacterium can increase the physiological activity and functionalization of soy embryo, which is a byproduct of processing.

• Journal of Microbiology and Biotechnology
• /
• v.27 no.11
• /
• pp.1952-1960
• /
• 2017

Recently, soybean isoflavone aglycones (i.e., daidzein and genistein) and ${\gamma}-aminobutyric$ acid (GABA) have begun to receive considerable consumer attention owing to their potential as nutraceuticals. To produce these ingredients, multiple microorganisms and their enzymes are commonly used for catalysis in the nutraceutical industry. In this work, we introduce a novel fermentation process that uses whole-cell biocatalysis to accelerate GABA and isoflavone aglycone production in doenjang (a traditional Korean soybean paste). Microbial enzymes transform soybean isoflavone glycosides (i.e., daidzin and genistin) and monosodium glutamate into soybean isoflavone aglycones and GABA. Lactobacillus brevis GABA 100 and Aspergillus oryzae KACC 40250 significantly reduced the production time with the aid of a protease. The resulting levels of GABA and daidzein were higher, and genistein production resembled the levels in traditional doenjang fermented for over a year. Concentrations of GABA, daidzein, and genistein were measured as 7,162, 60, and $59{\mu}g/g$, respectively on the seventh day of fermentation. Our results demonstrate that the administration of whole-cell L. brevis GABA 100 and A. oryzae KACC 40250 paired with a protease treatment is an effective method to accelerate GABA, daidzein, and genistein production in doenjang.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.64 no.2
• /
• pp.89-101
• /
• 2019

The variation of content of 12 soybean seed isoflavone components was determined in the aglycone, glucoside, malonylglucoside and acetylglucoside groups of 44 Korean soybean cultivars grown in 2016 as well as in 2017. The total isoflavone content of the 44 cultivars averaged at $2935.4{\mu}g/g$ and was in the range of 950.6 to $5226.3{\mu}g/g$ for two years. Malonylglucoside group averaged at $2437.2{\mu}g/g$ with the highest proportion of isoflavone composition (83.0%). Significant differences were observed between cultivars, years and their interactions for both the total isoflavone and each composition group contents (P < 0.0001); however, no year-wise differences were observed for daidzein and genistin. The broad-sense heritability ($h^2$) within the set of 44 Korean soybean cultivars was as high as 0.93 for the total isoflavone content and was in the range of 0.8-0.92 for each composition group of isoflavone except for acetylglucoside. The total isoflavone content in cultivar group for soy-sprout was higher ($3850.4{\mu}g/g$) than that for the other cultivar groups of soy-paste and tofu ($3082.8{\mu}g/g$), black or green soybean cooked with rice ($2345.8{\mu}g/g$), and early maturity group ($1298.6{\mu}g/g$). The total isoflavone content of 'Sowonkong', a soybean cultivar for soy-sprout, was the highest ($5226.3{\mu}g/g$). In the cultivar group for soy-paste and tofu, the average isoflavone contents of 'Daepung', 'Daepung2ho', 'Saegeum', 'Uram', and 'Jinpung' were higher than $4000{\mu}g/g$. With the exception of small seeded cultivars with low isoflavone contents such as 'Sohwang' and 'Socheongja', the seed size and total isoflavone content were significantly negatively correlated in 2016 and 2017, respectively ($r=-0.47^{**}$ and $-0.49^{**}$). The number of days of growth from flowering to maturity did not affect the variations observed in isoflavone content.

• Korean Journal of Food Science and Technology
• /
• v.38 no.4
• /
• pp.461-468
• /
• 2006

콩가루 50, 75, 100% 첨가 콩 반죽에 0, 1, 3%의 아몬드 첨가와 0, 20, 40분의 반죽 정치시간을 통해 제조 된 콩 과자 반죽에서 ${\beta}-glucosidase$ 활성을 측정하였고 콩 과자에서의 이소플라본 함량 및 aglycone 이소플라본 변화를 연구하였다. 일반적으로 콩가루 첨가량이 증가 될수록, 아몬드 첨가량이 증가할수록 반죽의 ${\beta}-glucosidase$ 효소 활성도는 높았으며 반죽 정치시간 20분이 0분이나 40분 보다 효소 활성이 유의적으로 높았다. 콩 과자 반죽에 포함된 이소플라본 함량은 예상된 함량 보다 약 15.2-31.5% 가량 적게 검출 되었다. 콩가루의 이소플라본 분포에 비해 콩 과자는 aglycones과 $6@-O-{\beta}-glucosides$는 증가하였고 $6@-O-malonyl-{\beta}-glucosides$는 감소하였다. 콩 과자의 aglycone 함량 증가에는 아몬드 첨가 보다 반죽 정치시간 증가가 더 효율적이었다.

• Korean Journal of Microbiology
• /
• v.43 no.1
• /
• pp.54-58
• /
• 2007

Fermented soybean, Chungkookjang contains microorganism, enzyme, and diverse bioactive compounds. Isoflavones in Chungkookjang might suppress breast and prostate cancers. Using HPLC and Mass analyses, it was found that 100% ethanol extract of Chungkookjang contains aglycone forms such as genistein, daidzein, and glycitein. 8-OH-genistein, 8-OH-daidzein were not found. There are two estrogen receptors, $ER{\alpha},ER{\beta}$. $ER{\alpha}$ might stimulate proliferation of breast and prostate cancer cells, and $ER{\beta}$ might suppress their growth. Using yeast transactivation assay under the control of human ER expression, it was demonstrated that isoflavones in Chungkookjang can stimulate $ER{\beta}_{1}$, selectively.

• Food Science and Preservation
• /
• v.24 no.1
• /
• pp.134-144
• /
• 2017

This study evaluated the changes of physiochemical properties, phytochemical compounds (isoflavones and phenolic acids), and biological activity during the fermentation of Doenjang without and with bitter melon powder (BMP). The pH decreased from 6.41-5.83 to 5.81-5.24, during the fermentation of Doenjang, while the acidity increased from 0.42-0.65% to 1.28-1.48%. The viable cell numbers of Bacillus and Yeast, salinity, and total amino acid contents increased at the end fermentation (60 day). Also, the fermented Doenjang (FD) with 10% BMP showed the highest ${\gamma}$-aminobutyric acid (GABA, 129.87 mg/100 g) contents, among all the Doenjang samples. The FD exhibited significantly higher inhibitory activities than unfermented Doenjang (UFD) on radicals and ${\alpha}$-glucosidase. The phytochemical compounds including isoflavone-aglycones and phenolic acids increased, whereas isoflavoneglycosides decreased in the BM following fermentative processing. Moreover, the total phenolic, isoflavone-aglycone, and phenolic acid contents were markedly increased, leading to a general increase in antioxidant and ${\alpha}$-glucosidase inhibition activities after fermentation. These results suggest that BMP may be used to prepare a new type of fermented Doenjang with improved antioxidant and antidiabetic activities.

• Korean Journal of Food Science and Technology
• /
• v.30 no.4
• /
• pp.745-750
• /
• 1998

Soybean isoflavones known as an anticarcinogenic factor were evaluated in some Korean soybean foods by high performance liquid chromatography. Unfermented soybean foods contained predominantly isoflavone ${\beta}-glycosides$ (genistin and daidzin), but in the fermented soybean foods isoflavones were present mainly as aglycones (genistein and daidzein). Average contents of isoflavones of tofu, soymilk and soy sprout were 1, 151, 676 and 424 mg/kg, respectively. Among the fermented soybean products, soybean paste (Chongkukjang) was highest in the isoflavone content (920 mg/kg) and the degree of hydrolysis of ${\beta}-glycosidic$ bonds was ranged from 30 to 100%. Doenjang, Chunjang and Kanjang contained lesser amounts of isoflavones and their contents were 627, 291 and 10 mg/kg, respectively. Korean traditional fermented foods, Chongkukjang and Doenjang could be regarded as the excellent sources of soy isoflavone aglycones.

• Korean Journal of Food Science and Technology
• /
• v.39 no.3
• /
• pp.231-236
• /
• 2007

The isoflavone distributions of soy samples treated with soaking, oven-drying, and almond additions were determined by high performance liquid chromatography (HPLC). Oven-drying was performed to increase the amount of ${\beta}-glucoside$ isoflavones, and almonds were added to convert the ${\beta}-glucosides$ into their corresponding aglycones. Oven-drying at $100^{\circ}C$ for 4 hr significantly increased ${\beta}-glucoside$ levels and decreased $malonyl-{\beta}-glucosides$, while almond additions of 2.5% and 5.0% (w/w) significantly increased aglycone contents (p<0.05) for samples with 12 hr of drying. The rate of increase for genistein from genistin was faster than that of daidzein from daidzin with almond additions. The ${\beta}-glucosidase$ activity in the 5.0% added almond soybean samples was significantly higher than in the samples without added almond (p<0.05). The aglycone content increased from 1.62% in the raw soybeans to 61.55% in the 2.5% added almond soybean samples for 12 hr of incubation. The information from this study could be used to increase the isoflavone aglycone contents of soybeans by using natural products such as almonds, without organic solvent additions or microorganism fermentation.