• 한국식품영양과학회지
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• 제26권3호
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• pp.371-375
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• 1997

The content of genistein and daidzein which were known to be major antioxidative compounds in soybeans were detected by $C_{18}$ reverse phase HPLC. Most of isoflavones in soybeans were detected in the methanol extract but much less amount of isoflavones in the water extract. Among the four different kind of soybeans, the isoflavone content was highest in brown soybean, followed by yellow, small black and black soybean, in the order. These isoflavones were known to be soluble in hot water, which means transfer of isoflavone content was highest in brown soybean, followed by yellow, small black and black soybean, in the order. These isoflavones were known to be soluble in hot water, which means transfer of isoflavones in soy curd into whey during soy curd processing. To identify the change of isoflavone content during processing of soybean curd, soybean curd were made from yellow, brown and black soybean and isoflavone content were determined in each soybean curd, curd residue and whey. Most of soflavones were remained in the whey, it means most of useful antioxidative compounds were wasted. Thus, it is necessary to develop new technology to collect these isoflavones lost during soybean curd processing.

• Journal of Nutrition and Health
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• 제38권1호
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• pp.40-47
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• 2005

This study was performed to determine the effect of three different concentrations of soy-isoflavones on calcium and phosphorus balance in either sham-operated or ovariectomized female rats. Seventy-two 16-week old Sprague-Dawley rats underwent sham operation or bilateral ovariectomy. They were provided diets containing different levels of soy iso-flavones for 6 weeks: 50 ppm (Jow isoflavone intake; LI) , 250 ppm (medium isoflavone intake; MI) and 500 ppm (high isoflavone intake; HI). The subsequent fecal and urinary excretions of calcium and phosphorus were then measured. In the sham-operated rats, body weight gains and food efficiency ratio of the MI and HI groups were significantly lower than the control group while food intake was not different. However, there was no significant difference in the ovariectomized rats. The fecal excretion of calcium was significantly lower in the LI, MI and HI groups than the control group in sham operated rats, and significantly lower in the HI group than the control group in ovariectomized rats. Also, apparent ab-sorption rate of calcium and phosphorus did not show any significant difference among groups. Urinary excretion of calcium and phosphorus was significantly lower in the HI group than the LI group in the sham-operated rats. Urinary excretion of calcium was significantly higher in the control ovariectomized rats than in the control sham-operated rats. Retention of calcium and phosphorus did not show any significant difference in both groups. From the above result, we see that isoflavone intake increases calcium retention through an increase in calcium absorption and also suppresses the increase of calcium excretion in urine in ovariectomy. Therefore, it is suggested that isoflavone intake is recommended for menopausal women who experience sharp bone loss due to the decrease in estrogen honnone.

• 한국식품영양과학회지
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• 제31권6호
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• pp.1043-1047
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• 2002

이소플라본의 섭취량 측정방법에서 식품중 함량분석이 미비한 실정이기 때문에 식이섭취조사 이외에도 소변을 통한 분석방법의 이용 가능성을 알아보고자 실시되었다. 전북 익산시에 거주하는 폐경 후 여성을 대상으로 3개월간 이소플라본 90mg을 함유한 대두 이소플라본 추출물을 매일 1회씩 섭취하도록 하고, 실험전과 실험 후반 3일간의 식이섭취조사와 1일간의 24시간 소변을 수집하여 소변으로의 이소플라본 배설량을 측정 비교한 결과를 요약하면 다음과 같다. 연구대상자 25명의 평균 연령은 64.2세였으며, 신장은 149.6 cm이었고, 체중과 체질량지수는각각 58.1 kg,25.9kg/m$^2$이었다. 연구대상자의 실험 전 열량 섭취량은 1일 평균 1337.5 kcal였으며, 이소플라본 공급기간 중에도 유의적인 차이를 보이지 않았다. 단백질의 섭취량은 실험전 1일 평균 56.9g으로 양호한 수준을 나타내었고, 이소플라본 공급 중에도 유의적인 차이를 보이지 않았다. 이외에 비타민 A, 카로틴, 비타민 C를 제외한 지질, 당질, 비타민, 무기질의 섭취량에 있어서도 실험 전과 실험 기간중에 유의적인 차이를 보이지 않았다. 일상식이중 총 이소플라본의 섭취량은 25.3 mg이었으며, 이중 다이드제인이 11.8 mg, 제니스테인이 13.5 mg이었다. 이소플라본 공급 기 간(90 mg/day)중 일상 식이를 통한 이소플라본의 섭취량은 21.5 mg으로 실험전과 유의적인 차이를 보이지 않았다. 이소플라본 공급전의 24시간 소변중 이소플라본(다이드제인과 제니스테인의 합) 배설량은 8.4 mg이었으며, 이소플라본 섭취량의 15.8%가 비례적으로 소변을 통하여 배설되었다. 매일 90mg의 이소플라본을 공급(90 mg/day)한 3개월 후에는 13.9mg으로 공급전에 비하여 유의적인 증가를 나타내었다(p<0.01). 이상의 결과를 통하여 24시간 소변을 통한 이소플라본 배설량 특히 다이드제인과 제니스테인의 측정은 이소플라본의 섭취수준을 파악할 수 있는 자료로 활용 가능성이 있음을 확인할 수 있었다. 그러나 본 연구는 대상자가 수가 적고 실험기관 공급수준의 다양성이 없다는 제한점을 가지고 있기 때문에 좀더 많은 인원수를 대상으로 기간과 섭취수준을 달리하는 등의 지속적인 연구가 수행되어야 할 것으로 사료된다.

• Journal of Nutrition and Health
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• 제38권2호
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• pp.89-95
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• 2005

This study was performed to investigate the effect of soy isoflavone on plasma nitrite concentration and the antioxidant enzyme activities of erythrocyte and the liver using adult male rats fed high fat diet. Seven-week old male Sprague Dawley rats were divided into three groups and fed high fat diet (15% beef tallow, 1 % cholesterol; control: IF0) or high fat diets containing isoflavone 80 ppm (IF80) or 320 ppm (IF320) for 10 weeks. Plasma nitrite concentration as a vasodilator, and antioxidant enzyme activities in erythrocytes and the liver were measured. Plasma nitrite concentration was increased by 45% and 35%, respectively, in IF80 and IF320 than in IF0 group. Erythrocyte catalase, glutathione peroxidase (GPx) and glutathione reductase (GR) activities increased by 31 %, 30% and 40% in IF320 compared to IF0 group. Especially, erythrocyte GR activity increased by 61 % in IF80 group. However, catalase activity in the liver was decreased in IF80 group. GPx and GR activities in the liver were not differ among groups. The results suggest that soy isoflavone have the protective effect against risk factors related with cardiovascular disease by improving vasodilator factor, nitrite, and antioxidant enzyme activities in blood. (Korean J Nutrition 38(2): 89～95, 2005)

• Bulletin of the Korean Chemical Society
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• 제35권6호
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• pp.1883-1886
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• 2014

• 동아시아식생활학회지
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• 제19권3호
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• pp.409-420
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• 2009

This study investigated preferences toward soybean-based foods and levels of dietary isoflavone intake in female adults living in Daegu. In order to determine the subjects' attitudes toward soybean-based foods their degrees of recognition and preference along with intake frequency were examined. To estimate their isoflavone intake levels, a food frequency questionnaire and the 24-hour recall method were used. The average age, height, weight, and BMI of the subjects were 47.3 years, 159.6 cm, 56.4 kg, and 22.1 kg/$cm^2$, respectively. And their mean energy, protein, dietary fiber, calcium, and sodium intakes were 1,871.9 kcal, 81.1g, 23.2 g, 604.7 mg, and 5.07 g, respectively. The average amount of isoflavones consumed from soy foods was 29.49 mg/day(daidzein 13.14 mg/day and genistein 16.35 mg/day) as assessed by food frequency questionnaire, and by the 24-hour recall method the average amount was 22.97 mg/day (daidzein 10.10 mg/day and genistein 12.87 mg/day), showing that the food frequency questionnaire assessment amount was 6.52 mg higher than that by 24-hour recall method. The major food sources of the isoflavones were soybean paste and soybeans. For the subjects' degrees of recognition of soybean food, soybean paste received the highest score among the items. The results also showed that the most preferred soybean-based foods were soybean paste stew and soybean paste soup. Furthermore isoflavone intake was significantly higher in the postmenopausal women than in the premenopausal women. Overall, these data help elucidate the patterns and determinants of soy food consumption and also provide an assessment of dietary soy isoflavone intake in Korean women.

• Journal of Microbiology and Biotechnology
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• 제25권4호
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• pp.469-478
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• 2015

In spite of the reported probiotic effects, Bifidobacterium bifidum BGN4 (BGN4) showed no βglucosidase activity and failed to biotransform isoflavone glucosides into the more bioactive aglycones during soy milk fermentation. To develop an isoflavone-biotransforming BGN4, we constructed the recombinant B. bifidum BGN4 strain (B919G) by cloning the structural β-glucosidase gene from B. lactis AD011 (AD011) using the expression vector with the constitutively active promoter 919 from BGN4. As a result, B919G highly expressed β-glucosidase and showed higher β-glucosidase activity and heat stability than the source strain of the β-glucosidase gene, AD011. The biotransformation of daidzin and genistin compounds using the crude enzyme extract from B919G was completed within 4 h, and the bioconversion of daidzin and genistin in soy milk during fermentation with B919G also occurred within 6 h, which was much faster and higher than with AD011. The incorporation of this β-glucosidase-producing Bifidobacterium strain in soy milk could lead to the production of fermented soy milk with an elevated amount of bioavailable forms of isoflavones as well as to the indigenous probiotic effects of the Bifidobacterium strain.

• 한국식품과학회지
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• 제46권5호
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• pp.556-565
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• 2014

잠재적인 생균제제 L. plantarum P1201의 두유 발효 중 이화학적 특성, 총 phenolics과 isoflavone 함량 및 항산화 활성 변화를 연구하였다. 균주 P1201는 pH 2.5의 산 및 인공위액산 환경에서 4 h 후 각각 58.14%와 62.22%의 생존율을 나타내었다. 두유 요구르트의 최적 발효 조건은 배양온도 $35^{\circ}C$, 종균 접종량 5.0% 및 10%의 sucrose이었다. 한편 총 phenolic와 isoflavone 함량 및 항산화 활성은 SM 요구르트보다 SPM 요구르트가 우수하였다. 특히 SPM 발효 48 h 후, daidzein, glycitein 및 genistein의 함량은 각각 91.50, 12.34 및 $61.39{\mu}g/g$이 검출되었다. 이러한 결과로 본 연구의 두유 요구르트 추출물은 잠재적인 천연 항산화제로 식품에서 사용할 수 있을 것으로 판단되었다.

• 한국식품과학회지
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• 제31권1호
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• pp.189-195
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• 1999

두유에 존재하는 이소플라본은 주로 포도당 잔기가 aglycone인 genistein과 daidzein에 ${\beta}-glycoside$ 결합을 하고 있는 배당체인 genistin과 daidzin이다. 두유에 설탕을 첨가하여 유산균으로 대두 요구르트로 발효를 시키면 젖산의 생성은 매우 낮아 약 $0.16{\sim}0.29%$에 불과하였지만 대부분의 이소플라본 배당체가 가수분해되어 aglycone으로 전환되었다. 포도당이나 젖당을 첨가하여 발효시키면 정상적인 젖산발효는 일어났지만 이소플라본 배당체의 가수분해는 균주에 따라 변하였다. Lactobacillus delbrueckii subsp. delbrueckii KCTC 1047은 당의 첨가와 무관하게 이소플라본 배당체를 완전히 가수분해시켰다. 그 밖의 균주는 daidzin은 약 $25{\sim}40%$, genistin은 약 $65{\sim}80%$ 정도만을 가수분해시켜 이들 당에 의해 가수분해가 감소하였다. 즉 Lactobacillus delbrueckii subsp. delbrueckii KCTC 1047을 제외한 Lactobacillus bulgaricus KCTC 3188, Lactobacillus casei KCTC 3109, Lactobacillus delbrueckii subsp lactis KCTC 1058, Lactobacillus lactis KCTC 2181과 같은 균주의 경우 이소플라본 배당체의 가수분해에 관여하는 효소인 ${\beta}-glucosidase$가 유도 효소로 포도당이나 젖당에 의해 생산이 저해되었을 것으로 예상된다. 또한 MRS 배지에서 배양하였을 때에도 Lactobacillus delbrueckii subsp. delbrueckii KCTC 1047만이 이 효소를 생산하였다.

• Preventive Nutrition and Food Science
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• 제10권3호
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• pp.290-293
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• 2005

Soy isoflavones have drawn much attention due to their potential to prevent breast and prostate cancers, osteoporosis, heart disease, and other postmenopausal symptoms. Soy germ is one of the richest sources of isoflavones, and thus has good potential to be used as the ingredient of health foods. This study examined the extraction rate of isoflavones from soy germ at various conditions. After the effect of extraction temperature and duration on isoflavones extraction from soy germ was examined, the optimum concentration of ethanol as extraction solvent was determined. When ethanol concentration was fixed at $60\%\;(v/v)$, the maximum isoflavone extraction was achieved at 2 hrs and $30^{\circ}C$. Among various concentrations of ethanol tested, $80\%\;(v/v)$ ethanol showed the highest extraction efficiency. In conclusion, the maximum extraction of isoflavones was obtained using $80\%\;(v/v)$ ethanol as a solvent, at $30^{\circ}C$ of temperature, and 2 hrs of extraction time.