Modeling of Nanofiltration Process for Solvent Recovery from Aqueous Ethanol Solution of Soybean Isoflavones

Abstract

In this paper, the feasibility of recovering the solvent from the aqueous ethanol solution of soybean isoflavones with nanofiltration (NF) was studied. Five commercially available polymeric NF membranes were employed and STARMEM? 122 showed acceptable flux and high retention. The central composite design (CCD) of the response surface methodology (RSM) was applied to model the effects of temperature, pressure, and feed concentration on the permeate flux and the total soybean isoflavone retention. The results indicate that the developed models were in good agreement with the experimental results and they can be used to predict this NF process.     

Assessment of the estrogenicity of the diet of a healthy female Spanish population based on its isoflavone content

Phytoestrogens are natural components of plants consumed by humans. The hormonal activity of these substances has long been known. Various in vitro tests have demonstrated the agonistic or antagonistic estrogenic activity of some phytoestrogens. The objective of this study was to estimate the supply of isoflavones in the diet of a healthy adult female population and to assess its estrogenic effect. The diet was assessed by questionnaire and the estrogenicity of the estimated isoflavone content was tested by E-screen, finding a mean total estrogenic capacity of 0.129 × 10^?10 eq.E₂ (12.9 pmol day^–1), corresponding to a daily isoflavone intake of 265.8 μg day^–1. This study offers a preliminary insight into the phytoestrogen content of the diet of a healthy active population of Spanish women. The effects of this additional hormonal burden are highly controversial, and this approach to estimating dietary phytoestrogen intake of specific populations may help to elucidate its implications for human health.     

Biotransformation of isoflavones by Aspergillus niger as biocatalyst

Biotransformation of the isoflavones, 6,7,4′‐trimethoxyisoflavone ( 1 ) and 5,7,4′‐trimethoxyisoflavone ( 2 ) by Aspergillus niger was investigated. Compound 1 was transformed to 4′‐hydroxy‐6,7‐dimethoxyisoflavone ( 3 ) and 2 to 4′‐hydroxy‐5,7‐dimethoxyisoflavone ( 4 ). This suggested that 1 and 2 were demethylated at the C‐4′ position with regioselectivity by Aspergillus niger. Copyright © 2006 Society of Chemical Industry     

HPLC法测定蓝花喜盐鸢尾中一种新的异黄酮糖苷

建立简单、快速的HPLC法测定蓝花喜盐鸢尾中一种全新异黄酮糖苷——鸢尾甲黄素B 4'-O-β-D-葡萄糖苷。采用HPLC法,Agilent 1260HC-C18(4.6 mm×250 mm,5μm)色谱柱,流动相为甲醇-1%冰醋酸梯度洗脱,流速为0.9 m L/min,检测波长为268 nm,柱温为25℃。结果表明,该异黄酮糖苷在17.2~172μg/m L浓度内线性关系良好,相关系数为0.999 4;回收率为99.78%(RSD=0.76%)。该检测方法准确灵敏,适用于蓝花喜盐鸢尾中鸢尾甲黄素B 4'-O-β-D-葡萄糖苷的测定。     

冠突散囊菌发酵对葛根的活性物质和抗氧化活性的影响

研究冠突散囊菌（Eurotium cristatum）发酵对葛根（Pueraria lobata）部分活性物质和抗氧化活性的影响,对发酵前后葛根的主要化学成分进行了分析比对,并简单研究了抗氧化活性的变化情况。以葛根为培养基质进行双向固体发酵,采用紫外分光光度法测定葛根发酵前后总黄酮含量变化;高效液相色谱法（HPLC）图谱叠加比对分析发酵前后葛根活性成分的变化,并对葛根的主要成分葛根素、大豆苷和大豆苷元3种异黄酮成分含量进行测定;DPPH法进行体外抗氧化活性测定。结果表明,发酵前后的样品总黄酮平均含量分别为5.08 mg/g和5.29 mg/g,表明发酵后葛根总黄酮含量有所提高;经HPLC检测计算,葛根中3种异黄酮成分葛根素、大豆苷元的含量分别是发酵前的1.6、4.9,而大豆苷的含量则降低了近1/2;而发酵前后葛根对DPPH自由基清除率的IC₅₀值分别为（2.2177±0.0484）和（0.8359±0.0047） mg/mL,差异显著,说明葛根经发酵后得到的发酵产物具有更强的体外抗氧化活性。结果表明,经冠突散囊菌发酵后葛根的主要化学成分变化显著,其体外抗氧化活性也得到极大改善。     

食品胶对豆浆中活性成分异黄酮苷元热稳定性的影响

研究了羧甲基纤维素钠(CMC)、海藻酸钠、黄原胶等食品添加剂对豆浆热处理过程中活性成分异黄酮苷元热稳定性的影响。高效液相色谱分析表明,CMC、黄原胶、海藻酸钠都能减少黄豆苷元、大豆黄素、染料木黄酮三种异黄酮苷元的热损失,其中CMC效果最理想,海藻酸钠次之,黄原胶最差。食品胶的复配能够减少豆浆中异黄酮苷元热损失。CMC/海藻酸钠组合明显好于CMC/黄原胶和黄原胶/海藻酸钠两种组合,当CMC/海藻酸钠=3∶2时,在热处理条件为95℃,10min条件下,各异黄酮苷元热损失最少,黄豆苷元含量提高9·83%,大豆黄素12·67%,染料木黄酮18·63%。在三种食品胶共同复配组合中,CMC/黄原胶/海藻酸钠(4∶3∶3)组合的效果最好,黄豆苷元含量提高9·3%,大豆黄素10·13%,染料木黄酮18·26%。      

大豆发芽过程中异黄酮、γ-氨基丁酸等成分含量变化的研究

研究了大豆发芽期间氨基酸、γ-氨基丁酸、大豆异黄酮、水分、总糖、可溶性蛋白质以及粗脂肪的含量变化。结果表明,大豆发芽48h时总游离氨基酸含量明显增加,水解氨基酸的含量略有增加但变化不明显;总糖、粗脂肪含量降低;水分含量升高;γ-氨基丁酸、大豆异黄酮等功能性因子含量都有明显提高,其中,发芽48h的大豆中γ-氨基丁酸的含量是干大豆的700%,发芽48h的大豆中大豆异黄酮的含量是干大豆的191·2%。      

超声波酸水解法提取豆渣中异黄酮条件优化

目的:对水酶法提取大豆油后的副产物进行研究,提取其生理活性物质大豆异黄酮。方法:采用超声方法和酸水解方法相结合对水酶法提取大豆油副产物进行异黄酮提取,在此基础上进行响应面优化,确定最佳提取工艺。结果:分析了影响异黄酮提取的各种因素,并予以优化。优化后工艺条件为:料液比为1:12.54,乙醇浓度为70.28%,盐酸浓度为2.6mol/L,水解提取时间为30min,提取温度为30℃。结论:超声波和酸水解的方法适用于水酶法提取油后豆渣中大豆异黄酮的提取,在加入酸水解后大豆异黄酮总提取量较单纯70%乙醇提取法提高42.55%。      

大豆异黄酮糖苷和苷元免疫功能研究

用大豆异黄酮糖苷和大豆异黄酮苷元喂养小鼠后,其鸡红细胞作免疫原的溶血素光密度值比在相同环境下空白对照组明显增加,这表明大豆异黄酮糖苷和苷元都能有效提高小鼠体液免疫功能;同时发现小鼠对大豆异黄酮苷元吸收效果强于大豆异黄酮糖苷,说明大豆异黄酮苷元免疫功能优于大豆异黄酮糖苷。     

前体和真菌诱导子对大豆悬浮培养细胞中异黄酮积累的影响

以高异黄酮含量的龙野01-491大豆为材料,以下胚轴为外植体诱导愈伤组织,建立大豆细胞悬浮培养体系;并研究了前体(L-phe和NaAc)、真菌诱导子(青霉和黑曲霉诱导子)对大豆悬浮细胞异黄酮积累的影响。结果表明,在细胞培养9 d加入100 μmol/L的L-phe,异黄酮产量达(12.52±0.51) mg/flask,是对照组的3.23倍;在0 d加入80 μmol/L NaAc,产量达(5.55±0.36) mg/flask,是对照的1.43倍;在9 d加入0.5 mL青霉诱导子,异黄酮产量达(10.20±0.17) mg/flask,是对照的2.56倍;在9 d加入0.5 mL黑曲霉诱导子,产量达(7.25±0.30) mg/flask,是对照的1.82倍。在大豆细胞悬浮培养过程中,通过添加前体(L-phe和NaAc)和真菌诱导子(青霉和黑曲霉诱导子)可以促进大豆异黄酮的积累。