Se improves indole glucosinolate hydrolysis products content, Se-methylselenocysteine content, antioxidant capacity and potential anti-inflammatory properties of sauerkraut

Selenium (Se) has a well-known role in prevention of chronic diseases associated with oxidative stress and inflammation. The objective was to produce Se-enriched sauerkraut and to study the effect of selenite addition on indole glucosinolate hydrolysis products, vitamin C, Se biotransformation and microbial quality. The antioxidant activity of sauerkraut and its ability to inhibit NO production in LPS-induced macrophages were also examined. White cabbage was naturally fermented with 0.3 mg of Na₂SeO₃/kg fresh cabbage (NFSe) or without Se addition (NF). Total Se content reached up to 1.29 μg/g d.m. (0.11 μg/g f.m.). Selenomethylselenocysteine was the major Se form found in NFSe cabbage. Se addition caused a slight reduction of ascorbigen (6%) and vitamin C (5%) contents in sauerkraut (P ? 0.05); however, lactic acid bacteria increased (3%), and the formations of indole-3-carbinol and indole-3-acetonitrile were markedly enhanced (74% and 13%, respectively). NFSe cabbage extracts showed higher (P ? 0.05) antioxidant activity (163 μmol trolox/g d.m.) and inhibition of NO production in LPS-induced macrophages (IC₅₀ = 44.0 μg/ml) than did NF cabbage extracts. Consequently, Se-enriched sauerkraut can be considered as a health-promoting food.     

液体培养杏鲍菇富集硒的条件与机理研究

用发酵液中添加亚硒酸钠的方法，对杏鲍菇富硒条件与机理进行研究。添加硒对菌丝生长有抑制作用，菌丝体中硒含量随着发酵培养基中硒浓度的上升而上升，当浓度达40μg／ml时达到最大，为1253．55μg／g；在低硒浓度硒条件下，SOD、POD酶活力随着硒浓度增加而增加，当培养基硒浓度分别达到30μg／ml和40μg／ml时达最高。有机硒占富集总硒98％，菌丝体可溶性蛋白中硒含量为1360．66μg／g。硒在菌丝内积累后，氨基酸总量增加19．68％。但胱氨酸仅仅占对照的86％，是唯一总量减少的氨基酸。这和硒代替硫形成含硒蛋白的机理一致。比较甘油、纤维素、淀粉、蛋氨酸、蛋白胨、柠檬酸六种添加剂对硒的影响表明，添加甘油有利于富集硒。培养基的初始pH为6．0，20℃，接种量为18％更有利于富集硒和菌丝生长。250ml三角瓶装80ml液体最有利于富集硒。     

转基因大豆对硒的富集作用和形态分布研究

目的研究转基因大豆对硒的富集作用以及富集前后转基因大豆中硒的形态分布和形态转化。方法 采用电感耦合等离子体质谱分析转基因大豆富集前后硒的总量,采用蛋白酶提取,高效液相色谱-电感耦合等离子体质谱(high performance liquid chromatography-inductively coupled plasma-mass spectrometry,HPLC-ICP-MS)联用技术分析转基因大豆中的硒酸盐(selenate,Se VI)、亚硒酸盐(selenite,Se IV)、硒代蛋氨酸(selenomethionine,Se Met)和硒代胱氨酸(selenocystine,Se Cys)等几种硒化合物。盆栽种植试验研究转基因大豆对硒的富集作用。通过对照试验,考察大豆植株不同部位总硒含量变化和形态分布的转化情况。结果转基因大豆对硒有较好的富集作用,吸收的亚硒酸盐在大豆植株中部分转化成了硒代蛋氨酸和硒代胱氨酸。结论 了解了转基因大豆的形态分布和转化情况,可以更好地评估转基因大豆的食用安全风险并进行生物利用开发。     

无花果不同部位中的营养成分分析

采用不同方法对无花果的枝、叶及果分别进行成分提取、测定了提取物中苯甲醛（紫外双波长法）、硒元素（比色法）、糖（高效液相色谱法）和蛋白质（凯氏定氮法）的含量。结果表明：苯甲醛和硒在叶中的含量最高；蛋白质在不同部位的含量均以水提取物为最高；糖的含量与其分子量大小及无花果的不同部位有关。这说明无花果的枝、叶及果均具有较高的食用和药用价值。以上研究结果为进一步综合开发利用无花果提供了实验依据。     

Enhanced selenium content in buckwheat (<Emphasis Type="Italic">Fagopyrum esculentum</Emphasis> Moench) and pumpkin (<Emphasis Type="Italic">Cucurbita pepo</Emphasis> L.) seeds by foliar fertilisation

The fruit and thin-husked seeds of the pumpkin (Cucurbita pepo L.) and buckwheat grain (Fagopyrum esculentum Moench), both grown in Slovenia, were analysed for selenium (Se) content following foliar application of Se(VI) solution during the period of blooming. Samples were digested by a H₂SO₄-HNO₃-H₂O₂-V₂O₅ mixture and Se determined, based on hydride generation atomic fluorescence spectrometry. The whole procedure from weighing to measuring was carried out in the same Teflon vessel. The detection limit of the method was 0.14 ng g^–1 solution. Buckwheat seeds from untreated plants contained 47 ng g^–1 of Se and 394 ng g^–1 from plants after foliar fertilisation with Se. Pumpkin seeds from untreated plants contained 108 ng g^–1 of Se, and 381 ng g^–1 of Se from Se-treated plants, all per lyophilised sample. Se content in lyophilised pumpkin fruit was 15 ng g^–1 in untreated plants and 20 ng g^–1 in Se-treated pumpkin plants. It is thus feasible to enhance Se content in buckwheat and pumpkin seeds by foliar fertilisation, making them a rich source of dietary Se and useful as a raw material for enriched food products.     

富硒大豆低聚肽的制备及其抗疲劳功能的研究

为探究富硒大豆低聚肽对抗运动性疲劳的影响,实验以富硒大豆为原料制备大豆分离蛋白,并以超滤萃取辅助中性蛋白酶和风味蛋白酶双酶酶解法制取富硒大豆低聚肽,并通过ICP-MS对硒含量进行鉴定,最后通过小鼠运动性疲劳实验综合评估富硒大豆低聚肽的抗疲劳活性。结果显示：富硒大豆低聚肽的总硒含量为90.03±3.23 mg/kg,主要形态为硒代蛋氨酸、硒代半胱氨酸。在运动性疲劳小鼠模型下,四组剂量组均能够延长小鼠负重力竭游泳时长,其中富硒大豆低聚肽高剂量组时间最长约为37.47±1.33 min,同时,血清生化指标显示小鼠的SOD酶、GSH-Px酶活性相较于模型组显著提高(P<0.05),MDA含量显著降低,肌糖原与肝糖原含量提高。综上,表明富硒大豆低聚肽对小鼠抗运动性疲劳具有积极作用,在100mg/kg.bw.d剂量组下抗疲劳效果显著。     

离子缔合体系测定痕量硒(Ⅳ)的研究与应用

在吐温-60存在下,研究了硒(Ⅳ)与硫氰酸钾和乙基罗丹明B形成的三元离子缔合物的吸收光谱特性,最大吸收峰为605nm,表观摩尔吸光系数ε605=1.50×106L/mol·cm,硒(Ⅳ)浓度在0.0~2.0μg/25mL范围内符合比耳定律。用巯基棉富集分离干扰离子,测定了水样和食品中痕量硒,结果满意。     

ICP-AES法快速测定铜冶炼废酸中铼、钼、硒含量的研究

采用硝酸处理试样,建立电感耦合等离子体发射光谱法同时测定铜冶炼废酸中铼、钼、硒含量的分析方法。通过实验选择各元素最佳分析谱线,并对基体干扰进行探讨。在选定的实验条件下,方法的检出限为0.6～7.0ng/mL,加标回收率为95.24%~104.83%。该方法应用于三种废酸中三种元素的分析,相对标准偏差为0.26%~4.67%。     

纳米硒的制备与应用研究进展

硒是生物体必需的微量元素之一,具有重要的生理功能,而纳米硒具有毒性低、生物活性高等特征.综述了载体/模板法、溶胶法、固相法等纳米硒的制备与保护方法,并简要介绍了纳米硒在保健食品、医药以及饲料添加剂等领域中的应用.     

Cadmium cathodic deposition on polycrystalline p-selenium: Dark and photoelectrochemical processes

Cathodic reduction of Cd²⁺ on p-Se proceeds at low overpotential in the dark and results in bulk Cd, while the underpotential deposition is kinetically inhibited. Cadmium adlayer is photoelectrochemically deposited on illuminated electrode 0.7 V above E(Cd²⁺/Cd). The adlayer cathodic deposition under illumination proceeds with simultaneous formation of CdSe nanoparticles. Potentiodynamic electrochemical impedance spectroscopy has discriminated the two products of the photoelectrochemical reaction both by their potentials of anodic oxidation and by characteristic dependences of impedance on potential. Anodic oxidation of CdSe nanoparticles gives a sharp peak of real impedance in low frequencies close to the corresponding anodic current peak in cyclic voltammogram. The impedance peak appears below a threshold frequency f_t. The latter separates two modes of diffusion in anodic dissolution of CdSe nanoparticles. The diffusion proceeds independently at different particles above f_t and turns to cooperative mode below the threshold frequency. Due to this effect, information on spatial distribution of growing nuclei on electrode surface in early stages of electrodeposition can be obtained from potentiodynamic impedance spectra.