• Journal of the Korean Society of Food Science and Nutrition
• /
• v.45 no.5
• /
• pp.680-689
• /
• 2016

The present study evaluated the validation method for isoflavone contents of fermented soybean extracts by bioconversion as well as their antioxidant activities. Our results show that the total isoflavone contents of non-fermented and fermented soybean extract ranged between 119.8 to $637.7{\mu}g/g$ and between 567.3 to $2,074.6{\mu}g/g$, respectively. Moreover, fermented soybean extracts had higher contents of isoflavone aglycones, including daidzein, glycitein, and genistein than non-fermented soybean extracts as well as lower contents of isoflavone glucosides such as daidzin, glycitin, and genistin. FRAP and ORAC values ranged between 0.15 to 0.22 and between 195.24 to $753.79{\mu}M$ Trolox equivalents/g in non-fermented and fermented soybean extracts, respectively. These results indicate that fermented soybean extracts had higher total isoflavone contents and antioxidant activities than non-fermented soybean extracts. Bioconversion process in this study may have the potential to produce isoflavone-enriched natural antioxidant agents with high added value from soybean matrices.

• The Korean Journal of Food And Nutrition
• /
• v.32 no.6
• /
• pp.643-650
• /
• 2019

The purpose of this study was to investigate the quality of dehulled soybean (DHSB), and the rapid preparation possibility of soybean milk with DHSB (SM-DHSB), and then the quality of SM-DHSB. In DHSB, the moisture content decreased, the crude protein, crude fat, minerals, and carbohydrate contents increased, and the isoflavone (daidzein, genistein and glycitein) content was similar to that of soybean (SB). The water absorption rate of DHSB for soybean milk preparation was higher than that of SB. In the results of SM-DHSB and soybean milk (SM) qualities, the crude protein content, total solid content, and the viscosity of SM-DHSB were higher, the yield and the proximate composition (except crude protein) were similar, and the Biji production rate, and total dietary fiber content of SM-DHSB were lower compared to the SM. In terms of the isoflavone contents of SM-DHSB, daidzein and genistein content were similar, and glycitein content was lower compared with the SM. Consequently, these results suggest the possible use of DHSB for rapid SM-DHSB preparation, because the soaking time was decreased by the high water absorption rate of DHSB in the SM preparation, and the quality of SM-DHSB improved compared to those of the SM.

• Korean Journal of Food Science and Technology
• /
• v.34 no.5
• /
• pp.916-918
• /
• 2002

The effect of acid hydrolysis on isoflavone contents of defatted soybean flour (DSF) was investigated in this study. Isoflavone analyzed were daidzein, genistein, glycitein, daidzein, genistein and glycitein with using HPLC. The DSF suspension was heated at $95^{\circ}C$ for 4 hour with addition of HCl (0.25-3.00 N) and analyzed isoflavone. The results showed that the total isoflavone was increased as the HCl concentration increased up to 1.0 N HCl during heating, indicating conversion of glucoside isomers of isoflavone to its aglycons. However, higher concentration than 1.0 N HCl caused a relatively fast decrease in isoflavone after 4 hour of heating. These results were probably caused by degradation of isoflavone by high concentration of acid during heating. The glucosides of isoflavone were steadily decreased while its aglycons were rather increased during $1.0{\sim}2.0$ hour of heating.

• Korean journal of food and cookery science
• /
• v.32 no.2
• /
• pp.197-203
• /
• 2016

Purpose: In this study, small black beans (Rhynchosia nulubilis) that were produced in the Jungsun province of South Korea were selected for use in various cooking recipes because they are known to contain higher isoflavones and excellent antioxidant effects, as compared to any other domestic soybeans. Methods: Physicochemical and antioxidant characteristics of small black beans were analyzed with uncooked beans and four other cooking methods of pan broiling, boiling, steaming, and pressure cooking. Results: Contents of ${\beta}$-glucosides (daidzin, glycitin, and genistin) and aglycone (daidzein, glycitein, and genistein) in small black beans were significantly different depending on the cooking methods (p<0.001). The results of the experiment indicated that the amount of total polyphenol in pressure cooked beans was highest, showing a value of 7.16 mg/g (p<0.001). Most contents of isoflavones (${\beta}$-glucoside, aglycone) in uncooked beans appeared to increase after cooking. In particular, the amount of glycitein was highest in pan broiled beans ($9.63{\mu}g/g$). The total isoflavone content differed among the different cooking methods, ranging from highest to lowest in the following order : pan broiled beans ($759.49{\mu}g/g$), pressure cooked beans ($725.12{\mu}g/g$), boiled beans ($591.05{\mu}g/g$), steamed beans ($511.61{\mu}g/g$), and uncooked beans ($180.80{\mu}g/g$) (p<0.001). Conclusion: Especially, the amount of isoflavones increased significantly in pan broiled beans and pressure cooked beans, suggestive of optimized cooking methods for increasing nutritional and functional contents in cooked food.

• Food Science and Biotechnology
• /
• v.15 no.4
• /
• pp.643-646
• /
• 2006

Cheonggukjang, a popular Korean traditional fermented soyfood, was manufactured by fermenting steamed soybeans in a temperature-controlled room by traditional methods in which steamed soy was exposed to rice straw naturally rich in Bacillus species. B. subtilus and B. licheniformis were found to be the major microorganisms present in cheonggukjang made by the traditional method. We analyzed the composition of 12 kinds of isoflavones and their glycosides present in cheonggukjang collected at various fermentation times. Total isoflavone content in raw soybeans was 2,867 mg/kg and this decreased by about 50% during cooking prior to cheonggukjang preparation. However, total isoflavone content changed slightly during 45 hr of fermentation. Total content of isoflavone glycosides, consisting mainly of daidzin, glycitein, and genistin, decreased by about 40% during 45 hr of fermenting cooked soybeans. The contents of tree isoflavones including daidzein, glycitein, and genistein showed a dramatic increase during fermentation in cheonggukjang preparation, with a 2.9-, 54.0-, and 20.6-fold increase in concentration, respectively, by the end of fermentation (45 hr). In conclusion, short-term fermentation of cooked soybeans with Bacillus species caused conspicuous changes in the composition of isoflavone derivatives, and its implication in terms of health benefits deserves further study.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.57 no.4
• /
• pp.424-429
• /
• 2012

This study was carried out to investigate the influence of different planting time on the synthesis of isoflavone in black soybean, Three varieties used in this experiment were lpumgeomjeongkong, Cheongjakong and Heugcheongkong which had different ecotypes, repectively. Seeds were sown at different time, May 15th, May 30th and June 15th with planting density of $60{\times}15cm$. In order to analyze the content of isoflavone, we collected sample every 5 days from 30 days after flowering to harvest and analyzed them with UPLC. As sowing was delayed, the content of isoflavone increased in all of three varieties. The content of genistein was greater than daidzein and glycitein. Increase of Glycitein was not distinct from 55 days after flowering(DAF) and it was stable against temperature change during the seed developing period. Although the content of genistein in Ilpumgeomjeongkong from 50 to 55 DAF, in Cheongjakong from 40 to 55 DAF and in Heugcheongkong from 60 to 65 DAF was lower than the content of daidzein, it was higher than that of daidzein afterward. In the statistical analysis on the relationship between average temperature and the content of aglycone isoflavone at 5-day intervals from 30 DAF during the grain filling period, genistein in Ilpumgeomjeongkong showed meaningful correlation as y=-15.28x+407.9 ($R^2=0.505^*$), diadzein in Cheongjakong showed meaningful correlation as y=-6.188x-164.5($R^2=0.454^*$), and genistein showed significantly high correlation as y=-11.59x+297.6 ($R^2=0.545^{**}$). Taking all the above results into consideration, it was suggested that the regions suitable for high content of isoflavone in black soybean be the northern area of Gyeonggi-do and Gangwon-do, Chungcheongbuk-do and inland area of Gyeongsangbuk-do, where are relatively low average temperature from flowering stage($R_2$) during the grain filling period.

• Food Science and Preservation
• /
• v.21 no.1
• /
• pp.121-128
• /
• 2014

This study was conducted in order to investigate the change of isoflavone composition (glycoside and bio-active aglycone), and to evaluate the quality characteristics of Cheonggukjang, which was prepared by different bacillus strains. After the 48-hour fermentation, the contents of daidzein, genistein, and glycitein in the Bacillus subtilis HJ18-3 have significantly increased up to approximately $89.06{\pm}3.59$, $10.36{\pm}0.28$, and $101.37{\pm}3.67ug/g$, respectively. The contents of daidzein, genistein, and glycitein in the Bacillus subtilis KACC 15935 were $38.88{\pm}5.39$, $12.58{\pm}2.14$, and $80.13{\pm}0.71ug/g$, respectively. The original content of daidzein was 3.96 ug/g, while genistein and glycitein were not measured. However, the contents of daidzen and genistein in HJ18-3 and in KACC 15935 were decreased. The ${\alpha}$-Amylase and cellulase activities of Chungkookjang in HJ18-3 were higher than in the KACC 15935. The contents of Chungkookjang in HJ18-3 were $29.70{\pm}11.66$ and $4861.3{\pm}388.07unit/g$, respectively. The amino type nitrogen contents and ammonia type nitrogen contents of Chungkookjang in KACC 15935 were higher than in the HJ18-3. These results suggested that it could be used to increase the bioactivity via fermentation with the Bacillus subtilis possessing a ${\beta}$-glucosidase activity with a view towards the development of functional foods.

• Preventive Nutrition and Food Science
• /
• v.12 no.1
• /
• pp.29-34
• /
• 2007

The production of mevinolin, a potent hypocholesterolemic drug, and the bioconversion of isoflavones were investigated in soybeans fermented with Monascus pilosus KFRI-1140. The highest yields of 2.94 mg mevinolins and 1.13 mg isoflavone aglycones per g dry weight of soybean were obtained after 20 days of fermentation. Mevinolin was present in the fermentation substrate predominantly in the hydroxycarboxylate form (open lactone, 94.8$\sim$96.7%), which is currently being used as an hypocholesterolemic agent. The significant (p<0.01) bioconversion (96.6%) of the glucoside isoflavones (daidzin, glycitin, genistin) present in the soybean to the bioactive aglycones (daidzein, glycitein, genistein), with a 15.8-fold increase of aglycones was observed. The results suggest that Monascus-fermented soybean has potential as a novel medicinal food or multifunctional food supplement.

• Korean Journal of Environmental Agriculture
• /
• v.29 no.2
• /
• pp.129-137
• /
• 2010

This experiment was conducted to investigate the variation of anthocyanin, and isoflavone contents in five cultivars and two lines of Korean domestic black soybeans grown at different latitudinal locations, a high latitude, Suwon ($37^{\circ}$16'N) and a low latitude, Milyang ($35^{\circ}$30'N). Delphinidin-3-glucoside (D3G) contents of anthocyanin in Geomjeongkong # 3 and Ilpumgeomjeongkong, cyanidin-3-glucoside (C3G) content in Milyang # 113, petunidin-3-glucoside (Pt3G) contents in Milyang # 113, and Ilpumgeomjeongkong, and total anthocyanins in Milyang # 113 were highest among the seven black soybean cultivars and lines. D3G, C3G, and total anthocyanins in Geomjeongkong # 3, C3G, and total anthocyanins in Ilpumgeomjeongkong grown at high latitude were higher compared to low latitude. Daidzein, glycitein, genistein, and total isoflavone contents in Geomjeongkong # 4 were highest among the seven cultivars and lines. Daidzein contents of isoflavone in Geomjeongkong # 3, Milyang # 112, and Milyang # 113 grown at high latitude were higher compared to low latitude. Glycitein contents in Geomjeongkong # 3, and # 4 grown at high latitude were higher compared to low latitude, while it in Milyang # 113 grown at low latitude was higher compared to high latitude. Genistein contents in most black soybeans except Milyang # 113, and total isoflavone contents in Geomjeongkong # 4 and Cheongjakong grown at low latitude were higher compared to high latitude. The variations of anthocyanin except Pt3G and isoflavone contents seemed to be affected by environmental conditions like different latitude than the genotype because they showed the significant interaction between cultivars and locations.

• Korean Journal of Microbiology
• /
• v.49 no.4
• /
• pp.391-397
• /
• 2013

Changes in ${\beta}$-glycosidase activity, total phenolic and isoflavone contents, and antioxidant activities during the fermentation of Korean black soybeans (Seoritae and Seomoktae) fermented food cheonggukjang by the potential probiotic Bacillus subtilis CSY191 were investigated. The levels of total phenolic and isoflavone-malonylglycoside and -aglycone contents increased, while 2,2-azinobis (3-ethyl-benzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radical scavenging activity and ferric reducing/antioxidant power (FRAP) increased, but the isoflavone-glycoside contents decreased after cheonggukjang fermentation. The content of antioxidant compounds, including isoflavone-aglycones and -malonylglycosides, was increased by fermenting-processing, whereas the content of isoflavone-glycosides was decreased in the fermented soybeans. In particular, the Seoritae soybean fermented at 3 $7^{\circ}C$ for 48 h displayed the highest antioxidant activities, compared to those of the Seomoktae soybean and the fermented. The highest levels of daidzein, glycitein, and genistein were present at concentrations of 253.0 ${\mu}g/g$, 72.5 ${\mu}g/g$, and 114.1 ${\mu}g/g$ after 48 h of Seoritae soybean fermentation. From those results, we suggest that the high antioxidant activity of cheonggukjang of black soybeans might be related to the markedly higher levels of total phenolic and isoflavone-aglycone and -malonylglycoside contents achieved during fermentation.