绿豆芽富硒特性及HPLC-MS联用法测定绿豆芽中硒代氨基酸

发布时间：2018-01-05 04:32

本文关键词：绿豆芽富硒特性及HPLC-MS联用法测定绿豆芽中硒代氨基酸　出处：《辽宁大学》2016年硕士论文　论文类型：学位论文

【摘要】：硒(Selenium, Se)是人体必需的微量元素,对人体有重要意义。它有增强免疫力、抗癌、抗氧化等重要的生理功能,在植物生长过程中向环境中添加无机硒可以通过植物自身的生物代谢将环境中的无机硒转化为植物组织中的有机含硒化合物,通过含硒植物补硒是缺硒地区提高人体硒水平的有效方法。植物体中的硒主要以有机硒和无机硒的形式存在,而相对于无机硒化合物,有机形态的硒化合物通常具有较高的生理功能及较低的毒性,如硒蛋白和硒代氨基酸。绿豆芽的蛋白质含量较高,且营养丰富,在绿豆的发芽过程中能更好地将环境中的无机硒转化为自身的有机硒。本文以自培富硒绿豆芽为对象研究硒对绿豆芽生长过程中生理特性及其含硒量的影响,同时测定绿豆芽可溶性蛋白质中的硒含量,并采用液相色谱-质谱联用技术对富硒绿豆芽中硒甲基硒代半胱氨酸、硒代蛋氨酸和硒代胱氨酸进行定性定量分析,得出结果如下：1、低浓度的硒对于绿豆芽的生长有一定的促进作用,当施硒浓度小于5mg/L时,绿豆芽的发芽率和长度与对照组比均有提高；当施硒浓度大于5 mg/L时,绿豆芽发芽率开始降低,在12 mg/L时较对照组降低30.3%,下胚轴及根的长度较对照组分别降低36.7%和31.6%。用考马斯亮蓝法测定绿豆芽中可溶性蛋白质含量表明绿豆芽中蛋白质含量在14%-19%范围内,且硒有利于增加绿豆芽中蛋白质的含量,即在一定程度上促进绿豆芽营养成分的合成。2、以HN03为消解剂,采用微波消解-石墨炉原子吸收光谱法对富硒绿豆芽中总硒含量进行消化及测定,研究不同消解剂量的使用对样品消化效果的影响,结果表明,在1-12 mg/L施硒范围内,绿豆芽中总硒含量随着外源施硒浓度的增加而增大,在施硒浓度为12mg/L时绿豆芽中总硒含量达到最大值7275μg/kg,但高浓度的硒会对绿豆芽的生长产生毒害,抑制绿豆芽的生长。3、以超纯水、HCl、aOH、Tris-HCl为浸提剂,对富硒绿豆芽中溶解态硒进行提取并测定其含量,结果表明,绿豆芽中可溶态硒的分布规律为：酸溶态碱溶态Tris-HCl溶解态水溶态。各个溶解态硒含量均随施硒浓度增加而增大,酸溶态、碱溶态、Tris-HCl溶解态和水溶态中硒含量分别占总硒量的50%-55%、35%-45%、30%-35%和20%-30%。说明在酸性介质中,硒更容易通过绿豆芽进行迁移转化,从而更能被人体吸收利用。采用碱溶酸沉等电点法对富硒绿豆芽中可溶性蛋白质进行提取,研究碱液浓度、料液比、浸提时间、浸提温度及等电点对蛋白质提取率的影响,最佳的提取条件为：提取液浓度0.20 mol/L、料液比1：50、浸提时间90 min、浸提温度40℃及等电点pH为4.8,在此条件下提取绿豆芽可溶性蛋白质,使用微波消解仪对蛋白质沉淀进行消化,并使用石墨炉原子吸收光谱法测定蛋白质中的硒含量。结果表明,绿豆芽蛋白质中硒含量随着施硒浓度的增加而增大,最高浓度为1710μg/kg,占总硒含量的23.5%。高浓度的硒不仅能增加蛋白质中硒含量,且能增大蛋白质中硒占总硒的比例。4、采用PLC-MS联用法对富硒绿豆芽样品中硒代胱氨酸、硒代蛋氨酸和硒甲基硒代半胱氨酸进行定性定量分析,对每种氨基酸进行裂解电压和碰撞能的优化,选择最佳提取条件,采用MRM模式进行监测。结果表明,硒甲基硒代半胱氨酸是富硒绿豆芽中的主要硒代氨基酸；而硒代蛋氨酸和硒代胱氨酸的含量相对较小,仅占总硒含量的5%以下。因此,绿豆芽可以通过其生长代谢过程将无机硒有效地转化成有机硒,作为营养、安全、高效的功能性补硒食品,是提高低硒地区人体内含硒水平的有效途径。
[Abstract]:Se (Selenium, Se) is an essential trace element, has important significance to the human body. It has enhanced immunity, anticancer, antioxidant and other important physiological functions, adding inorganic selenium to the environment in the process of plant growth through biological metabolism of plants in the environment of inorganic selenium into organic plant tissues selenium compounds, the selenium selenium selenium deficiency in plant is an effective method to improve the level of selenium in plants. Selenium mainly exists in the form of organic and inorganic selenium, rather than inorganic selenium compounds, physiological function of selenium compounds in organic form usually have higher and lower toxicity, such as protein and seleno amino acids. The protein content of mung bean is high, and rich nutrition, during the germination of mung bean can better inorganic selenium into organic selenium in the environment itself. Based on the self training of selenium enriched mung bean Discusses the effect of selenium on bud growth and physiological characteristics of mung bean sprouts in the process and the content of selenium, and selenium content of soluble protein in mung bean sprouts, and using liquid chromatography-mass spectrometry of Se methylselenocysteine enriched mung bean sprouts, qualitative and quantitative analysis of selenomethionine and selenocystine the results were as follows: 1, the low concentration of selenium for a certain role in promoting the growth of mung bean sprouts, when the selenium concentration is less than 5mg/L, the germination rate and the length of mung bean sprouts than in the control group were increased; when the concentration of selenium was greater than 5 mg/L, mung bean germination rate began to decrease at 12 mg/L when compared with the control group decreased 30.3%, hypocotyl and root length were decreased by 36.7% and 31.6%. by Coomassie brilliant blue method for the determination of soluble protein content in mung bean sprouts that mung bean protein content in the range of 14%-19% compared with the control group, and selenium To increase the protein content of mung bean sprouts, which promote the.2 synthesis of mung bean nutritional ingredients in a certain extent, with HN03 as the digesting agent, used to digest and determination of total selenium content in mung bean sprouts with Microwave Digestion Graphite furnace atomic absorption spectrometry, study the different effects of fire, use solution dosage on the effect sample digestion results showed that in the 1-12 mg/L range of selenium, the total selenium content in mung bean sprouts increased with increasing exogenous selenium concentration, the concentration of selenium is 12mg/L total selenium content in mung bean sprouts reached a maximum value of 7275 g/kg, but high concentration of selenium on growth of mung bean sprouts poison the growth inhibition of.3, mung bean sprouts, with ultra pure water, HCl, aOH, Tris-HCl as extraction agent, the dissolved selenium enriched mung bean sprout extract and determine the content, the results show that the distribution of soluble selenium in mung bean sprouts are: acid soluble alkali soluble Tris-H Cl dissolved water soluble selenium content. All were dissolved with the selenium concentration increased, acid soluble, alkali soluble Tris-HCl, soluble and water soluble selenium content in selenium respectively of the total amount of 50%-55%, 35%-45%, 30%-35% and 20%-30%. in acidic medium, selenium is easier to transfer the green bean sprouts, so it can be absorbed by human body. By alkali solution and acid isoelectric point method for soluble protein enriched in mung bean sprouts were extracted on alkali concentration solid-liquid ratio, extraction time, effects of extraction temperature and the isoelectric point of the protein extraction rate, the best extraction conditions are: the concentration of 0.20 mol/L, solid-liquid ratio 1:50, extraction time 90 min, extraction temperature of 40 DEG C and isoelectric point of pH was 4.8, the extraction of soluble protein in mung bean under this condition, the precipitated proteins were digested using microwave digestion instrument, and using graphite furnace atomic absorption spectrometry measurement Set the selenium content in protein. The results showed that the selenium content of mung bean protein increases with the concentration of selenium, the highest concentration was 1710 g/kg, the total selenium content in high concentration of 23.5%. can not only increase the selenium content of selenium in protein, and can increase the total protein of selenium in selenium by ratio of.4. PLC-MS method for generation of selenium enriched mung bean samples of cystine, selenomethionine and Se methylselenocysteine in qualitative and quantitative analysis, optimize the cracking voltage and collision energy of each amino acid, choose the best extraction conditions, using MRM mode monitoring. The results showed that Se methylselenocysteine is the main se selenium in mung bean sprouts on behalf of amino acids; and selenomethionine and selenium content of cystine is relatively small, only the total selenium content is below 5%. Therefore, mung bean sprouts can be through the growth and metabolism of inorganic selenium effectively Transforming into organic selenium, as a nutritive, safe and efficient functional selenium supplement, is an effective way to improve the level of selenium in the human body in the low selenium area.

【学位授予单位】：辽宁大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：S649;O657.63

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