Anti-photoaging effects of soy isoflavone extract (aglycone and acetylglucoside form) from soybean cake

Soy isoflavones, found in soybean and soybean products, have been reported to possess many physiological activities such as antioxidant activity, inhibition of cancer cell proliferation, reduction of cardiovascular risk, prevention of osteoporosis and alleviation of postmenopausal syndrome. In our previous study, soy isoflavone extract ISO-1 (containing 12 soy isoflavones) from soybean cake was demonstrated to prevent skin damage caused by UVB exposure. In this study, soy isoflavone extract from soybean cake was further purified and evaluated for the protective effects on UVB-induced damage. The results revealed that Fraction 3, which contains the aglycone group (daidzein, genistein and glycitein) and acetylglucoside group (acetyldaidzin, acetylgenistin and acetylglycitin) of soy isoflavones, could inhibit UVB-induced death of human keratinocytes and reduce the level of desquamation, transepidermal water loss (TEWL), erythema and epidermal thickness in mouse skin. Furthermore, topical application of Fraction 3 increased the activity of catalase and suppressed cyclooxygenase-2 (COX-2) and proliferating cell nuclear antigen (PCNA) expression in mice exposed to UVB. In addition, in comparison with ISO-1 and genistein, the Fraction 3 possessed much greater protective effects on both UVB-induced oxidative stress and keratinocyte death than other fractions. Therefore, the soy isoflavone extract Fraction 3 from soybean cake is a desirable anti-photoaging agent for skin care.     

Enhancement of Biological Properties of Soymilk by Fermentation

Soymilk has attracted much interest in the food industry because of its health- promoting properties. Fermentation with lactic acid bacteria is known to provide value addition to soymilk by reducing the beany flavor and content of indigestible oligosaccharides and by enhancing the bioavailability of isoflavones, resulting in a nutritious probiotic food product. In the present study, Soymilk fermentation was studied using Lactobacillus acidophilus strain isolated from ragi, and effect of soymilk supplementation on the fermentation characteristics was also investigated. Viable count of 1.99 × 10⁹ CFU/mL sample and 630.1 U/g of β-glucosidase activity were determined in soymilk after 12 h of fermentation. Soymilk supplementation with skimmed milk powder at 5% level gave best results with viable counts of 22.9 × 10⁹ CFU/ml sample or 212.9 × 10⁹ CFU/g solids; 764 U/g of β-glucosidase activity, 1.44% la titratable acidity and pH of 3.9. Daidzein and genistein profile in fermented soymilk showed that 45.8% and 57.5% of respective isoflavones existing as aglycone form, indicating enhancement of the biological property of soymilk through improvement of health-relevant bioactive forms.     

用大孔吸附树脂分离大豆糖蜜中异黄酮的研究

选择6种大孔吸附树脂分离大豆糖蜜中的异黄酮,考察大孔吸附树脂对大豆糖蜜中异黄酮的吸附能力,并以糖蜜中异黄酮浓度、吸附液流速、吸附液pH值为参数进行单因素试验.结果表明:最佳树脂为LS-800,其静态吸附率为64.12％,静态解吸率为69.39％;动态吸附条件为:吸附液中异黄酮质量浓度1.23 mg/mL,吸附液流速1 mL/nin,吸附液pH值4.0,吸附率为89.50％;动态解吸条件为:解吸液为体积分数为80％乙醇水溶液,解吸液流速1 mL/min,解吸率为86.22％.经大孔树脂分离纯化后,产品中的异黄酮含量为56.03％,回收率为68.82％.     

响应面法优选银杏果中异黄酮提取工艺研究

以银杏果为原料,通过对索氏提取时间、固液比、乙醇体积分数、提取温度单因素试验确定最佳单因素水平并做响应面优化实验,确定了以乙醇为提取剂提取银杏果中异黄酮化合物的最佳工艺条件．然后采用紫外分光光度法测定异黄酮质量分数．结果表明,最佳提取工艺为：索氏提取时间5 h ,固液比1∶30,乙醇体积分数80％,提取温度97．45℃．在最佳条件提取后采取紫外分光光度计测定,回收率为98．15％,精密度为3．391％,银杏果异黄酮质量分数为2．255 m g／g ．     

红三叶草异黄酮对去卵巢大鼠血脂及骨量的影响

目的:研究红三叶草异黄酮对去卵巢大鼠血脂及骨量的影响。方法:将体质量250±10g雌性大鼠随机分为5组:假手术组(灌胃蒸馏水)、模型组(灌胃蒸馏水)、雌激素组(乙烯雌酚)、红三叶草异黄酮处理组(高、低剂量)。除假手术组外,其他各组均切除双侧卵巢,假手术组行相同手术操作,但不切除卵巢。各组动物均在相同的环境中饲养,自由摄食和饮水,造模1周后开始喂药。实验8周后对大鼠双股骨骨密度和骨矿含量进行检测,心脏取血测定血脂并计算动脉粥样硬化指数。结果:与模型组比较,红三叶草异黄酮高剂量组能够增加去卵巢大鼠骨密度、骨矿含量;随红三叶草异黄酮剂量的增加大鼠血清HDL-胆固醇有升高趋势,并有降低总胆固醇、甘油三脂、LDL-胆固醇和AI的作用。结论:红三叶草异黄酮不仅可以维持去卵巢大鼠骨密度,而且具有调节血脂的功能,对骨和心血管系统具有良好的保护作用。     

纳豆咀嚼片中总异黄酮的含量测定

建立测定纳豆咀嚼片中总异黄酮含量的方法-紫外分光光度计法,以染料木素作为对照品,利用染料木素与氢氧化钠产生反应,并在275 nm波长处产生最大吸收峰的特性,用紫外分光光度法测定纳豆咀嚼片中总异黄酮含量.测定结果:纳豆咀嚼片中总异黄酮的含量为325μg/片,加样回收率为98.3%.     

青方腐乳发酵过程中大豆异黄酮的转化研究

本文比较了青方、红方、白方和低盐红腐乳中大豆异黄酮组成和含量差异,并对青方腐乳发酵过程中大豆异黄酮含量和构型变化规律进行研究。结果表明,四种类型腐乳中大豆异黄酮基本以苷元形式存在,青方腐乳大豆异黄酮含量明显低于其他类型腐乳,仅为红方腐乳的33.01%,从单一异黄酮来看,大豆苷元和染料木素在四种类型腐乳中的含量明显高于黄豆黄素;青方腐乳发酵过程中大豆异黄酮转化研究发现,白坯中大豆异黄酮以糖苷型为主,染料木苷含量高于大豆苷和黄豆黄苷,前酵过程中糖苷型大豆异黄酮转化为苷元型大豆异黄酮,盐腌过程中糖苷型大豆异黄酮含量有轻微降低,发酵过程中苷元型大豆异黄酮总量在后酵前30 d显著下降,其中大豆苷元可能部分转化为雌马酚,导致青方腐乳大豆异黄酮含量明显低于其他类型腐乳,对其转化物质需进一步鉴定。     

Analysis of isoflavone content in tempeh, a fermented soybean, and preparation of a new isoflavone-enriched tempeh

To produce a tempeh-like functional food containing a high level of isoflavone with a high absorptivity, we analyzed changes in the composition of isoflavone during tempeh fermentation and the difference in isoflavone content depending on the soybean variety and particular tissue. By adding soybean germ (hypocotyl) that contained a large amount of isoflavone, we prepared a new isoflavone-enriched tempeh in the form of a granular fermented soybean-based food, which can serve as a nutritious supplement for the elderly.     

酶水解对大豆异黄酮粗提物中苷元含量的影响

采用β-葡萄糖苷酶水解的方法将大豆异黄酮糖苷转化为苷元,以染料木素和大豆苷元含量为指标,通过单因素试验对水解过程中的不同影响因素进行了考察。以染料木素含量为指标,运用正交试验优化了β-葡萄糖苷酶水解大豆异黄酮的工艺条件为反应温度40℃、水解时间1.5h、水解介质pH4.5、水解底物浓度10mg/mL,在此条件下,水解得到的大豆异黄酮苷元中染料木素的含量可达到22.91%。     

酱油中异黄酮物质的分离与鉴定

本采用真空肖缩干燥酱油、乙酸乙酯热回流抽取酱油中黄酮物质,并使用薄层层析法进行纯化,分离。