摘要目的:探讨富硒茶叶中有机硒的高效提取方法及其赋存形态。方法:采用持续透析法和差减法进行有机硒提取方法优选，同时根据Osborne溶解性蛋白质的分类及性质，顺序浸提水溶、盐溶、醇溶及碱溶蛋白4种蛋白质。利用体外模拟技术模拟富硒茶叶中硒在胃肠液的消化过程，采用原子荧光光度计-液相色谱联用法进一步分析人体摄入硒的生物可利用度及有机硒在茶叶中的赋存形态。结果:富硒茶叶总硒含量为（303.12 ± 1.19）μg/kg，持续透析法、差减法测得有机硒含量分别为（154.76 ± 9.47）、（265.02 ± 6.55）μg/kg，二者比较差异有统计学意义（ t=- 2.56， P < 0.05）。4种蛋白质含量由大到小依次为碱溶蛋白（29.79 g/100 g）、水溶蛋白（2.52 g/100 g）、盐溶蛋白（2.15 g/100 g）、醇溶蛋白（1.04 g/100 g）。经胃肠液消化模拟，茶叶样品的硒含量为（203.01 ± 3.16）μg/kg，硒的生物可利用度为66.97%；醇溶蛋白中硒代蛋氨酸（SeMet）含量为（13.87 ± 3.21）μg/kg，硒代半胱氨酸（SeCys）含量为（0.82 ± 0.38）μg/kg；碱溶蛋白中SeMet含量为（2.59 ± 2.16）μg/kg。 结论:富硒茶叶的有机硒提取方法中，差减法优于持续透析法。富硒茶叶中SeMet在醇溶、碱溶蛋白中均可检出，SeCys在醇溶蛋白中可检出。

abstractsObjective:To explore the efficient extraction method of organic selenium from selenium-rich tea and its occurrence form.Methods:The continuous dialysis method and the subtraction method were used to optimize the extraction method of organic selenium. At the same time, the four proteins (water-soluble, salt-soluble, alcohol-soluble, alkali-soluble proteins) were sequentially extracted according to the classification and properties of Osborne soluble proteins. In vitro simulation technology was used to simulate the digestion process of selenium in selenium-rich tea in the gastrointestinal fluid, and the bioavailability of human intake of selenium and the occurrence form of organic selenium were further analyzed by atomic fluorescence spectrometer-liquid chromatography. Results:The total selenium content of selenium-rich tea was (303.12 ± 1.19) μg/kg. The contents of organic selenium measured by the continuous dialysis method and the subtraction method were (154.76 ± 9.47) and (265.02 ± 6.55) μg/kg, respectively, the difference was statistically significant ( t=- 2.56, P < 0.05). The contents of four proteins in descending order were alkali-soluble protein (29.79 g/100 g), water-soluble protein (2.52 g/100 g), salt-soluble protein (2.15 g/100 g), and alcohol-soluble protein (1.04 g/100 g), respectively. After digestion simulation of gastrointestinal fluid, the selenium content of tea samples was (203.01 ± 3.16) μg/kg, and the bioavailability of selenium was 66.97%. The content of selenomethionine (SeMet) in alcohol-soluble protein was (13.87 ± 3.21) μg/kg, and the content of selenocysteine (SeCys) was (0.82 ± 0.38) μg/kg; the content of SeMet in alkali-soluble protein was (2.59 ± 2.16) μg/kg. Conclusions:In the extraction method of organic selenium from selenium-rich tea, subtraction method is better than continuous dialysis method. SeMet in selenium-rich tea can be detected in alcohol-soluble and alkali-soluble proteins, and SeCys can be detected in alcohol-soluble protein.