【摘要】：硒是存在于地殼中的一種痕量元素,對人體和動植物十分重要。硒具有很強的生物活性,是谷胱甘肽過氧化物酶的組成成分,硒缺乏引起動物心肌病及肝壞死、動物生長和發(fā)育不良。植物能夠積聚無機硒,通過一系列生物化學反應將無機硒轉(zhuǎn)化為毒性低生物利用率高的有機硒,從而成為天然補硒劑。葡萄的營養(yǎng)成分豐富,通過富硒技術生產(chǎn)富硒葡萄對改善葡萄的品質(zhì)、提高葡萄的經(jīng)濟收益具有重要意義。本論文以葉面噴施硒肥的葡萄為研究對象,研究外源硒在葡萄中的生物富集和不同形態(tài)硒的相互轉(zhuǎn)化的影響,具體研究內(nèi)容包括:1.富硒葡萄的培養(yǎng)及葡萄中硒的分析方法研究在溫室大棚內(nèi)通過葉面噴施濃度為40-200mg/kg的硒肥培養(yǎng)富硒葡萄,考察其富硒特性。選擇微波密閉消解法快速高效消解葡萄,氫化物發(fā)生原子熒光光譜法對富硒葡萄中的硒含量進行分析,優(yōu)化樣品取樣量,微波消解條件,酸度和硼氫化鈉用量。考察該方法的精密度,檢出限和回收率。結(jié)果表明:葡萄在施硒量為40-200mg/kg范圍內(nèi)長勢良好。1g富硒葡萄干樣在2ml HNO3-1ml H_2O_2消解體系中消解,儀器測定時選用5%鹽酸和20g/L硼氫化鈉。該方法定量分析富硒葡萄中硒含量時的檢出限為0.79μg/L,精密度為1.54%,回收率為97.3%~101.9%,適合富硒葡萄中硒含量的測定。2.富硒葡萄中不同硒形態(tài)的分布研究選擇最佳溫度和時間提取葡萄中不同形態(tài)的硒,了解其分布規(guī)律。結(jié)果表明最佳提取條件為:堿溶態(tài)硒為45℃下提取60min;酸溶態(tài)硒為35℃下提取60min;水溶態(tài)硒和Tris-HCl態(tài)硒為35℃下提取40min。對葡萄中可溶性硒研究可知:堿溶態(tài)酸溶態(tài)Tris-HCl態(tài)水溶態(tài)。施硒量為160mg/kg時,堿溶態(tài)硒含量高達1791.36mg/kg,表明葡萄將外源硒轉(zhuǎn)化為不同形態(tài)硒,人體體液呈堿性時可能更益于對硒的吸收。3.富硒葡萄中的蛋白質(zhì)和多糖提取工藝研究與抗氧化性分析結(jié)合單因素試驗及響應面法提取優(yōu)化富硒葡萄中的可溶性蛋白質(zhì)和可溶性多糖,比較分析富硒葡萄中的蛋白硒和多糖硒含量,對比硒蛋白和硒多糖與同濃度的普通蛋白和多糖的抗氧化性。結(jié)果表明:在浸提劑濃度0.1mol/L,液料比16:1,提取時間97min,浸提溫度44℃時,富硒葡萄可溶性蛋白提取率可達到0.35%;在液料比22:1,提取時間64min,浸提溫度77℃,重復提取2次時,富硒葡萄中的可溶性多糖提取率為6.61%;葡萄中蛋白硒和多糖硒與施硒量呈正相關,其占總硒的比例在施硒量為160mg/kg時達到最大分別為3.24%和40.58%,硒蛋白和硒多糖分別比同質(zhì)量濃度普通蛋白質(zhì)和多糖具有更高的抗氧化性。富硒葡萄可以作為一種良好的天然抗氧化劑。4.HPLC-ESI-MS技術對富硒葡萄中硒代氨基酸的分析水浴超聲法提取富硒葡萄中的有機硒,采用HPLC-ESI-MS對水提物中的Se-Me Se Cys、Se-Met和Se Cys2進行定量定性分析,優(yōu)化儀器條件,確定Se-Me Se Cys、Se-Met和Se Cys2的定量檢測離子對分別為m/z為184-167,m/z為198-109和m/z為337-248。結(jié)果表明,隨著施硒量的增加,三種硒代氨基酸的含量均先增加后降低,但Se Met和Se Cys2在施硒量為160mg/kg時最大,而Se-Me Se Cys則在施硒量80mg/kg時達到最大值隨后緩慢下降。Se-Met含量最高,Se Cys2含量最少,在施硒量為160mg/kg時Se-Met的含量為Se-Me Se Cys和Se Cys2的2倍。因此富硒葡萄可以作為缺硒人群攝取硒代蛋氨酸等有機硒的來源之一。
[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，

本文編號：2371416