葡萄富硒特性及硒的形态分析
发布时间：2018-12-10 23:31
【摘要】：硒是存在于地壳中的一种痕量元素,对人体和动植物十分重要。硒具有很强的生物活性,是谷胱甘肽过氧化物酶的组成成分,硒缺乏引起动物心肌病及肝坏死、动物生长和发育不良。植物能够积聚无机硒,通过一系列生物化学反应将无机硒转化为毒性低生物利用率高的有机硒,从而成为天然补硒剂。葡萄的营养成分丰富,通过富硒技术生产富硒葡萄对改善葡萄的品质、提高葡萄的经济收益具有重要意义。本论文以叶面喷施硒肥的葡萄为研究对象,研究外源硒在葡萄中的生物富集和不同形态硒的相互转化的影响,具体研究内容包括:1.富硒葡萄的培养及葡萄中硒的分析方法研究在温室大棚内通过叶面喷施浓度为40-200mg/kg的硒肥培养富硒葡萄,考察其富硒特性。选择微波密闭消解法快速高效消解葡萄,氢化物发生原子荧光光谱法对富硒葡萄中的硒含量进行分析,优化样品取样量,微波消解条件,酸度和硼氢化钠用量。考察该方法的精密度,检出限和回收率。结果表明:葡萄在施硒量为40-200mg/kg范围内长势良好。1g富硒葡萄干样在2ml HNO3-1ml H_2O_2消解体系中消解,仪器测定时选用5%盐酸和20g/L硼氢化钠。该方法定量分析富硒葡萄中硒含量时的检出限为0.79μg/L,精密度为1.54%,回收率为97.3%~101.9%,适合富硒葡萄中硒含量的测定。2.富硒葡萄中不同硒形态的分布研究选择最佳温度和时间提取葡萄中不同形态的硒,了解其分布规律。结果表明最佳提取条件为:碱溶态硒为45℃下提取60min;酸溶态硒为35℃下提取60min;水溶态硒和Tris-HCl态硒为35℃下提取40min。对葡萄中可溶性硒研究可知:碱溶态酸溶态Tris-HCl态水溶态。施硒量为160mg/kg时,碱溶态硒含量高达1791.36mg/kg,表明葡萄将外源硒转化为不同形态硒,人体体液呈碱性时可能更益于对硒的吸收。3.富硒葡萄中的蛋白质和多糖提取工艺研究与抗氧化性分析结合单因素试验及响应面法提取优化富硒葡萄中的可溶性蛋白质和可溶性多糖,比较分析富硒葡萄中的蛋白硒和多糖硒含量,对比硒蛋白和硒多糖与同浓度的普通蛋白和多糖的抗氧化性。结果表明:在浸提剂浓度0.1mol/L,液料比16:1,提取时间97min,浸提温度44℃时,富硒葡萄可溶性蛋白提取率可达到0.35%;在液料比22:1,提取时间64min,浸提温度77℃,重复提取2次时,富硒葡萄中的可溶性多糖提取率为6.61%;葡萄中蛋白硒和多糖硒与施硒量呈正相关,其占总硒的比例在施硒量为160mg/kg时达到最大分别为3.24%和40.58%,硒蛋白和硒多糖分别比同质量浓度普通蛋白质和多糖具有更高的抗氧化性。富硒葡萄可以作为一种良好的天然抗氧化剂。4.HPLC-ESI-MS技术对富硒葡萄中硒代氨基酸的分析水浴超声法提取富硒葡萄中的有机硒,采用HPLC-ESI-MS对水提物中的Se-Me Se Cys、Se-Met和Se Cys2进行定量定性分析,优化仪器条件,确定Se-Me Se Cys、Se-Met和Se Cys2的定量检测离子对分别为m/z为184-167,m/z为198-109和m/z为337-248。结果表明,随着施硒量的增加,三种硒代氨基酸的含量均先增加后降低,但Se Met和Se Cys2在施硒量为160mg/kg时最大,而Se-Me Se Cys则在施硒量80mg/kg时达到最大值随后缓慢下降。Se-Met含量最高,Se Cys2含量最少,在施硒量为160mg/kg时Se-Met的含量为Se-Me Se Cys和Se Cys2的2倍。因此富硒葡萄可以作为缺硒人群摄取硒代蛋氨酸等有机硒的来源之一。
[Abstract]:Selenium is a trace element present in the earth's crust and is of great importance to the human body and animals and plants. Selenium has strong biological activity, is a component of glutathione peroxidase, and the lack of selenium causes animal cardiomyopathy and liver necrosis, animal growth and dysplasia. The plant can accumulate the inorganic selenium, and the inorganic selenium is converted into organic selenium with low toxicity and low bioavailability through a series of biochemical reactions, so as to form a natural selenium supplement. The nutritional components of the grape are rich, and the selenium-rich grape can be used for producing the selenium-rich grape to improve the quality of the grape and improve the economic benefit of the grape. The effects of exogenous selenium on the bioaccumulation of selenium in the grape and the interconversion of different forms of selenium in the grape were studied in this paper, and the content of the study was as follows: 1. The selenium-rich grape was cultured in the greenhouse, and the selenium-rich grape was cultured through the selenium fertilizer with the concentration of 40-200mg/ kg on the surface of the greenhouse, and the selenium-rich characteristics of the grape were studied. The content of selenium in the selenium-rich grape was analyzed by microwave-sealed digestion, and the content of selenium in the selenium-rich grape was analyzed by atomic fluorescence spectrometry. The sample amount, the microwave digestion condition, the acidity and the amount of sodium borohydride were optimized. The precision, detection limit and recovery of the method were investigated. The results showed that the content of selenium in grape was good in the range of 40-200mg/ kg. 1g of selenium-rich raisin was digested in 2ml of HNO3-1ml H _ 2O _ 2 digestion system, and 5% hydrochloric acid and 20 g/ L of sodium borohydride were used in the determination of the instrument. The detection limit of selenium in the selenium-rich grape was 0.79 & mu; g/ L, the precision was 1.54%, the recovery rate was 97.3% ~ 101.9%, and it was suitable for the determination of the selenium content in the selenium-rich grape. The distribution of the different forms of selenium in the selenium-rich grape was studied, and the optimum temperature and time were selected to extract the selenium in different forms of the grape. The results showed that the optimum extraction conditions were as follows: the alkali-soluble selenium was extracted at 45 鈩，
本文编号：2371416
[Abstract]:Selenium is a trace element present in the earth's crust and is of great importance to the human body and animals and plants. Selenium has strong biological activity, is a component of glutathione peroxidase, and the lack of selenium causes animal cardiomyopathy and liver necrosis, animal growth and dysplasia. The plant can accumulate the inorganic selenium, and the inorganic selenium is converted into organic selenium with low toxicity and low bioavailability through a series of biochemical reactions, so as to form a natural selenium supplement. The nutritional components of the grape are rich, and the selenium-rich grape can be used for producing the selenium-rich grape to improve the quality of the grape and improve the economic benefit of the grape. The effects of exogenous selenium on the bioaccumulation of selenium in the grape and the interconversion of different forms of selenium in the grape were studied in this paper, and the content of the study was as follows: 1. The selenium-rich grape was cultured in the greenhouse, and the selenium-rich grape was cultured through the selenium fertilizer with the concentration of 40-200mg/ kg on the surface of the greenhouse, and the selenium-rich characteristics of the grape were studied. The content of selenium in the selenium-rich grape was analyzed by microwave-sealed digestion, and the content of selenium in the selenium-rich grape was analyzed by atomic fluorescence spectrometry. The sample amount, the microwave digestion condition, the acidity and the amount of sodium borohydride were optimized. The precision, detection limit and recovery of the method were investigated. The results showed that the content of selenium in grape was good in the range of 40-200mg/ kg. 1g of selenium-rich raisin was digested in 2ml of HNO3-1ml H _ 2O _ 2 digestion system, and 5% hydrochloric acid and 20 g/ L of sodium borohydride were used in the determination of the instrument. The detection limit of selenium in the selenium-rich grape was 0.79 & mu; g/ L, the precision was 1.54%, the recovery rate was 97.3% ~ 101.9%, and it was suitable for the determination of the selenium content in the selenium-rich grape. The distribution of the different forms of selenium in the selenium-rich grape was studied, and the optimum temperature and time were selected to extract the selenium in different forms of the grape. The results showed that the optimum extraction conditions were as follows: the alkali-soluble selenium was extracted at 45 鈩，
本文编号：2371416
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