发酵处理对豆豉抗氧化活性影响的研究

发酵处理基本上不改变豆豉中异黄酮的总含量,而糖苷型大豆异黄酮在β-葡萄糖苷酶的作用下部分转化为游离型大豆异黄酮,使游离型大豆异黄酮的含量明显提高;在样品未添加任何抗氧化剂的前提下,通过试验发现豆豉的自身抗氧化性比原料熟黑豆强许多。     

发酵处理对大豆制品中异黄酮含量与组分的影响

利用发酵大豆食品———豆豉与酸豆乳作为试验对象 ,通过与对照品比较 ,发现发酵处理对大豆食品中的异黄酮总含量的影响不大 ,但对其异黄酮的组分有较大的影响 ,发酵处理使糖苷型大豆异黄酮在 β 葡萄糖苷酶的作用下水解为游离型大豆异黄酮 ,从而使发酵制品中的游离型大豆异黄酮的含量增高 ,而糖苷型大豆异黄酮的含量降低     

豆豉加工前后营养与活性成分变化的研究

豆豉加工处理可以使豆豉中游离氨基酸、维生素B1、维生素B2、可溶性糖的含量增加;发酵处理基本上不改变豆豉中异黄酮的总含量,而糖苷型大豆异黄酮在β-葡萄糖苷酶的作用下可转化为游离型大豆异黄酮,使游离型大豆异黄酮的含量明显提高。     

高产大豆异黄酮糖苷转化酶乳酸菌的筛选及其发酵条件的优化

采用高效液相色谱法测定发酵豆乳中游离型大豆异黄酮含量,以此为指标,从传统发酵食品分离筛选的100株乳酸菌中,选出一株发酵后游离型大豆异黄酮产量最高的作为生产功能性发酵豆乳的发酵菌株。经生理生化及遗传学特性鉴定该菌株为植物乳杆菌。并通过单因素和响应面优化实验对影响游离型大豆异黄酮产量的3个发酵因素,即发酵时间、发酵温度、接种量,进行优化,得出最佳发酵条件为:发酵温度45℃、发酵时间17h、接种量5%,在此条件下游离型异黄酮的产量为132.814μg/mL。     

永川豆豉传统发酵过程中的大豆异黄酮变化

为了探明永川豆豉在传统发酵过程中大豆异黄酮总含量和构成变化,采用高效液相色谱技术对永川豆豉传统发酵过程中大豆异黄酮总量和构成进行测定。结果表明：永川豆豉在发酵加工过程中大豆异黄酮总含量由发酵起始的3117mg/kg下降到豆豉成熟时的1754mg/kg;大豆异黄酮构成变化显著,游离苷元型大豆异黄酮含量迅速增加由发酵起始的3.2%上升到豆豉成熟时的95.7%,同时结合糖苷型大豆异黄酮含量迅速降低。     

两步固态发酵对发酵大豆功能成分的影响研究

研究经枯草芽孢杆菌DC-12-步发酵所得发酵大豆Ⅰ(FBB Ⅰ)和经曲霉前发酵、DC-12后发酵两步发酵所得发酵大豆Ⅱ(FBB Ⅱ)中含氮成分、含糖成分、脂类成分、异黄酮苷元含量及豆豉纤溶酶酶活力的变化.结果表明:FBB Ⅱ中非蛋白氮含量为黑豆的8.0倍,FBB Ⅰ的2.0倍;氨基酸态氮含量为黑豆的6.4倍,为FBB Ⅰ的2.1倍;游离脂肪酸含量为黑豆的63.2倍,为FBB Ⅰ的14.0倍;还原糖和总糖含量均低于FBB Ⅰ;异黄酮类组分大豆苷元和染料木素含量分别为黑豆中的25.6倍和15.5倍,为FBB Ⅰ的3.2倍和1.9倍;豆豉纤溶酶产量略低于FBB Ⅰ.结论:两步发酵法所得产品优于一步发酵法.     

不同光照条件下大豆发芽过程中异黄酮含量比较与抗氧化活性研究

比较了小黄豆和小黑豆在光照和避光下发芽后大豆异黄酮的含量和分布,并对其抗氧化活性进行测定分析。小黄豆和小黑豆发芽后,子叶中大豆异黄酮含量均有所降低,芽茎中的大豆异黄酮含量有所增高。两种大豆在避光下发芽,芽茎和子叶中大豆异黄酮的含量均高于在光照条件下发芽。两种光照条件下发芽小黑豆中大豆异黄酮含量均高于小黄豆中大豆异黄酮的含量。小黄豆的抗氧化活性与其中的大豆异黄酮含量具有相同的变化趋势,但是小黑豆的抗氧化活性与其大豆异黄酮含量的变化趋势不同,小黑豆原豆和子叶的抗氧化活性均高于芽茎,这可能与小黑豆的表皮中含有花青素有关。     

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。     

浏阳豆豉发酵过程中抗氧化成分及活性变化研究

通过测定大豆异黄酮、总黄酮、总多酚含量的变化,结合发酵过程中浏阳豆豉的抗氧化活性的变化,来探讨浏阳豆豉抗氧化活性变化的机理。结果表明:虽然总黄酮与总大豆异黄酮的含量逐步减少,但发酵初期原料中大豆异黄酮主要为糖苷型(占85.75%),而发酵末期则主要为更具活性的苷元型大豆异黄酮(占81.41%),且总多酚经发酵从2.78 mg/g提升至5.76 mg/g,发酵最后一天(L20)豆豉的总抗氧化能力、DPPH·、·OH、O₂-·清除率分别增加至1088.91 U/g、93.67%、90.24%、88.38%,此外相关性结果表明苷元型大豆异黄酮要比总多酚对豆豉抗氧化活性的影响更大。实验证明发酵有助于大豆中总多酚的增加以及糖苷型大豆异黄酮向苷元型大豆异黄酮转换,这是提高豆豉抗氧化能力及功能性的关键因素之一。     

添加微量元素对黑豆发芽过程中成分的影响

目的:研究微量元素对黑豆发芽过程中成分变化的影响。方法:采用HPLC法对添加一定量微量元素Zn、Mn、Cu、Fe发芽的黑豆中大豆苷、染料木苷、大豆苷元和染料木素进行含量测定;采用紫外分光光度法对黑豆中总黄酮的含量进行测定;采用高效凝胶过滤色谱法对肽分子量分布进行测定;采用比色法对多肽、游离氨基酸和植酸进行含量测定;采用火焰原子吸收光谱法、电感耦合等离子体原子发射光谱法对微量元素进行含量测定。结果表明:添加微量元素对黑豆发芽过程中成分影响较明显,最终选定的微量元素浓度为:硫酸锌30 mg/L、硫酸锰20 mg/L、硫酸铜10 mg/L、硫酸亚铁20 mg/L。通过定量分析,黑豆添加微量元素发芽与清水发芽的黑豆16 d相比,异黄酮苷元增长了88.24%;游离氨基增加了87.29%;植酸含量则减少了30.86%。结论:黑豆添加微量元素发芽有利于异黄酮苷元、游离氨基酸等营养成分的生成,营养价值更高。     

Enhancements of isoflavone aglycones, total phenolic content, and antioxidant activity of black soybean by solid-state fermentation with Rhizopus spp.

In the present study, a solid-state fermentation process of black soybean was developed. Three filamentous fungi including Rhizopus oligosporus (BCRC 31996), R. oligosporus (NTU-5), and Rhizopus oryzae (BCRC 30894) were cultivated with steam-cooked intact and dehulled black soybeans. It was found that fermentation enhanced the total phenolic and isoflavone aglycone content as well as antioxidant activity of the black soybean methanol [80 % (v/v)] extracts. Among the three candidates, R. oligosporus BCRC 31996 was chosen as the working strain, and dehulled Tainan NO.3 black soybeans were used as the substrate based on the relatively high total phenolic content, isoflavone aglycone accumulation, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging effect of the fermented extracts. In a 6-day fermentation, extracts of the fermented dehulled black soybeans yielded higher total phenolic content (2,876.2 μg/g) which was 1.16 times of the result from the intact soybean extracts. The DPPH scavenging effect of the fermented dehulled black soybean extract reached its maximum on the third day. The activity of β-glucosidase of dehulled black soybean samples increased with time and resulted in accumulation of isoflavone aglycones. The product of solid-state black soybean fermentation serves as a functional ingredient in the products of nutritional supplements and health foods.     

Characterization of fermented black soybean natto inoculated with Bacillus natto during fermentation

BACKGROUND: To make nutrients more accessible and further increase biological activity, cooked black soybeans were inoculatedwith Bacillus natto and fermented at 37 °C for 48 h. The changes in physiochemical properties of fermented black soybean natto were investigated. RESULTS: The inoculation procedure significantly increased moisture, viscosity, color, polyphenol compounds and anthocyanin, and significantly decreased hardness after 48 h fermentation. Fibrinolytic and caseinolytic protease, β‐glucosidase activities, TCA‐soluble nitrogen, and ammonia nitrogen contents in the inoculated samples significantly increased as fermentation time increased. Genistin and daidzin concentrations gradually decreased with increased fermentation time. However, genistein and daidzein increased with fermentation time, which reached 316.8 and 305.2 µg g^?1 during 48 h fermentation, respectively. DPPH radical scavenging activities of the fermented black soybeans increased linearly with fermentation time and concentration. Compared with the soaked black soybeans and cooked black soybeans, the fermented black soybeans with B. natto resulted in higher scavenging activity towards DPPH radicals, which correlated well with the content of total phenols (r = 0.9254, P < 0.05) and aglycone isoflavone (r = 0.9861, P < 0.05). CONCLUSION: Black soybean natto fermented by B. natto has the potential to become a functional food because of its high antioxidant activity. Copyright © 2010 Society of Chemical Industry     

Effect of soybean varieties on the content and composition of isoflavone in rice-koji miso

To clarify the effect of soybean varieties on isoflavone, a useful component for human health, in soybean products, we investigated changes in the isoflavone content and composition in rice-koji miso, after fermentation/aging for 6 or 12 months using varieties of soybeans (Tohoku-126, Tohoku-135, Tohoku-139, Suzuyutaka and Chinese soybeans), by high performance liquid chromatography. In soybeans, the total isoflavone content in Tohoku-126 was 444 mg/100 g, which was 1.2–2.0 times the content in the other soybean varieties. The malonyl glycosides and aglycones in soybeans accounted for more than 60% and only a few percent, respectively. As for rice-koji miso, the total isoflavone and aglycone contents were the highest in miso prepared from Tohoku-126. The ratios of glycosides to aglycones (80.1–92.6%) in miso were higher than those in the original soybeans. The time course of the isoflavone composition during the fermentation/aging process of rice-koji miso indicated that glycosides decreased from 86.4% to 44.9% after 6 months but aglycones increased from 9.6% to 53.3%.     

Biological activities of cheonggukjang prepared with several soybean cultivars

To select proper soybean cultivars for producing functional cheonggukjang, a comparison was made of the physiological activities of different cheonggukjang prepared with 30 different soybean cultivars. The isoflavone content was highest in the cheonggukjang made from ‘Daepung’ soybeans at 208.75 mg%. In general, the contents of glycone types (and derivatives) of isoflavone, specifically daidzin, glycitin, genistin, and malonylgenistin, were higher than that of aglycone types. The polyphenol contents ranged from 30.62 to 80.32 mg%. The DPPH radical scavenging activity and superoxide dismutase (SOD)-like activity of the cheonggukjang made from yellow soybeans had a higher activity than those of black soybeans. Although there are no consistent tendencies in the functional activity of cheonggukjang according to soybean color and size, the antioxidative activity is highest in the cheonggukjang made of yellow soybeans. Additionally, the fibrinolytic and inhibitory activities against angiotensin I-converting enzyme are highest in the cheonggukjang made of black soybeans. From these results, it can be concluded that the DPPH free radical scavenging activity and SOD-like activity in cheonggukjang depends on the phenolic compound content in soybean.     

Soluble phenolics and antioxidant properties of soybean (Glycine max L.) cultivars with varying seed coat colours

This research was the first to investigate nutritional components, including soluble phenolics (isoflavones and anthocyanins), protein, oil, and fatty acid as well as antioxidant activities in different coloured seed coat soybeans (yellow, black, brown, and green) for two crop years. The soluble phenolics differed significantly with cultivars, crop years, and seed coat colours, while protein, oil, and fatty acid exhibited only slight variations. Especially, malonylgenistin and cyanidin-3-O-glucoside compositions had the most remarkable variations. Green soybeans had the highest average isoflavone content (3079.42 μg/g), followed by yellow (2393.41 μg/g), and black soybeans (2373.97 μg/g), with brown soybeans showing the lowest value (1821.82 μg/g). Anthocyanins showed only in black soybeans, with the average contents of the primary anthocyanins, cyanidin-3-O-glucoside, delphinidine-3-O-glucoside, and petunidin-3-O-glucoside, quantified at 11.046, 1.971, and 0.557 mg/g, respectively. Additionally, Nogchae of green soybean and Geomjeongkong 2 of black soybean may be recommended as potential cultivars owing to the highest average isoflavone (4411.10 μg/g) and anthocyanin (21.537 mg/g) contents. The scavenging activities of 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) radicals also differed remarkably, depending upon isoflavone and anthocyanin contents, with black soybeans exhibiting the highest antioxidant effects.     

Enhancement of antioxidant activity,total phenolic and flavonoid content of black soybeans by solid state fermentation with Bacillus subtilis BCRC 14715

In the present study, a solid state fermentation of black soybeans with Bacillus subtilis BCRC 14715 was performed. The effect of fermentation on the changes of total phenolic and flavonoid content and antioxidant activities including 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical-scavenging effect, and Fe²⁺-chelating ability exerted by various solvent (water, 80% methanol, 80% ethanol, 80% acetone) extracts of black soybeans was examined. It was found that fermentation enhanced the total phenolic and flavonoid content as well as antioxidant activity of the black soybean extract. Among the various extracts examined, the acetone extract of fermented black soybeans showed the highest total phenolic and flavonoid content. The acetone extract and the methanol extract of fermented black soybeans showed the highest DPPH free radical-scavenging effect and Fe²⁺-chelating ability, respectively. Analysis of extraction yields showed that the active principle associated with the DPPH radical-scavenging effect was most efficiently extracted from black soybeans using water, regardless of fermentation. Water and methanol effectively extract the Fe²⁺-chelating principles from non-fermented and fermented black soybeans, respectively.     

Effect of acetic acid treatment on isoflavones and carbohydrates in pickled soybean

Acetic acid treatment improves the physical, chemical, and physiological properties of soybeans. This study investigated the changes in isoflavone and carbohydrate profiles in four soybean cultivars subjected to different acetic acid treatment durations. The sum of total isoflavone content of the pickled soybeans and the pickling solution was increased by 30–93% after acetic acid treatment for 30 days. In the comparison to four isoflavone groups of the untreated soybean, malonyl glucosides were decreased by 17–41%, whereas glucosides were increased by 54–160% in the pickled soybeans. In particular, aglucones were found in the pickled soybeans, but not in the untreated soybeans. Following acetic acid treatment, the total carbohydrate content in the pickled soybeans was 50–65% less than that of untreated soybeans. In particular, oligosaccharides and sucrose in the pickled soybeans decreased significantly (> 50%) within the first 24 h. This study provides important information on the changes in isoflavone and certain carbohydrates profiles during soybean pickling, and may be useful to produce functional soybean-based foods containing more bioactive compounds.     

Biological activities of fermented soybean paste (Doenjang) prepared using germinated soybeans and germinated black soybeans during fermentation

To produce doenjang with enhanced biological activities, doenjang was prepared by fermenting regular soybeans (RS), germinated soybeans (GS), and germinated black soybeans (GBS) for 90 days. The isoflavone contents in GS and GBS-doenjang were slightly higher than in RS-doenjang in the early stage of fermentation. The DPPH radical scavenging activity of GBS-doenjang was highest at 70.00% after 30 days of fermentation. The angiotensin-converting enzyme (ACE) inhibiting effects increased as the fermentation period progressed, and were significantly (p<0.05) higher in GBS-doenjang (58.69%) than in other preparations after 75 days of fermentation. The greatest fibrinolytic activities were 127.59 and 100.00% in nontreated GBS-doenjang and GBS-doenjang treated for 30 min at 55°C, respectively. There were significant (p<0.05) correlations between the total isoflavone content and the antioxidant activity (0.779) and between the isoflavone content and the ACE activity-inhibiting effects (0.669). GBS-doenjang exhibited greater antioxidant activities, ACE-inhibition, and fibrinolytic activities than RS and GS-doenjang.     

Chromatographic fingerprints and quantitative analysis of isoflavones in Tofu-type soybeans

Tofu-type soybeans can differ from conventional soy varieties in seed size, seed composition, flavour and nutrition. Using HPLC coupled with ESI-MS and PDA detection, a total of 19 isoflavones were detected and identified from Tofu-type soybean seeds, more than previously reported forms from many other soybeans. An HPLC/UV fingerprint study was performed for qualitative evaluation, which enabled the isoflavone profile of Tofu-type soybeans to be characterised and differentiated from other vegetative soybeans by similarity comparison. To meet the frequent quantitative application for isoflavone contents, a simple, precise and reliable method using HCl hydrolysis during sample extraction and LC/UV for the detection was developed and validated to quantitate total isoflavones in soybeans, and then applied to determine the total isoflavone contents of different Tofu-type soy varieties grown in different field locations over two growing seasons. A range of total isoflavone contents for Tofu-type soybeans was established to confirm the use of this analytical approach for quality control applications.     

不同品种大豆异黄酮组分及体外抗氧化活性分析

为研究不同品种大豆异黄酮组分和含量以及抗氧化活性,测定了50个特色大豆品种的百粒重、色泽（L*、a*、b*）,通过高效液相色谱法（HPLC）测定异黄酮组分,评估不同品种大豆甲醇提取物的DPPH、ABTS自由基清除能力,并用相关性分析、主成分分析及聚类分析法对样品进行分析。结果表明:大豆的百粒重范围为7.05~47.46 g。不同种皮色大豆L*、a*和b*呈现显著差异（P<0.05）。HPLC分析结果发现糖苷型异黄酮含量是大豆中主要的异黄酮组分,占总异黄酮含量的90%以上。其中染料木苷含量最高。安豆115品种的大豆异黄酮的总含量最高,为2500.78 μg/g;靖江丝瓜青品种的大豆异黄酮含量最低,为888.86 μg/g。安豆115品种的DPPH和ABTS自由基清除能力较强,分别为（16.11±0.25）和（8.12±0.04）μmol V_C/g。糖苷型异黄酮含量与DPPH和ABTS自由基清除能力有较高的线性相关性（R2分别为0.903和0.867）。主成分分析表明6项指标可用2个主成分来表示（累计贡献率达66.3%）。聚类分析将50个品种的大豆分为4类:第一类中黄豆黄素和黄豆黄苷含量较高;第二类中大豆苷、大豆苷元、染料木苷和染料木素含量较高;第三类和第四类中其大豆异黄酮含量基本处于中等水平和较低含量。综上所述,不同大豆品种的异黄酮组成、含量和抗氧化能力存在较大差异,可为其进一步综合开发利用提供一定理论基础。