Effects of Rare Earth on the Accumulation of Selenium in Soybean Sprouts

Effects of Rare Earth on the Accumulation of Selenium in Soybean Sprouts
　　The selenium-enriched soybean sprouts were prepared with soybean as raw materials, and add 10μg·mL-1 selenium and different concentrations of rare earth La3+、Ce3+、Nd3+ into cultivation solution by soaking and spraying. The effect of rare earth on accumulation of selenium in soybean sprouts was studied .And content of total selenium were determined by using a fluormetric method; The content of organic selenium is analyzed by the method of still-placed and oozing-out the inorganic selenium. The result indicates that rare earth can promote soybean sprouts to Neodymium Magnets absorb Se and increase the content of total selenium and organic selenium, but the impact of different rare earth element has discrepancy. The most effective rare earth element is La.
　　When the concentrations of La3+ is below 6μg·mL-1, content of total selenium and organic selenium were both raised gradually with the increase of the La concentration, but decreased when the concentrations of La3+ is above 9μg·mL-1. 6μg·mL-1 La3+ exhibits the strongest promotion ability on the accumulation of Se in sprouts, content of total selenium and organic selenium was increased to 65.68μg·g-1 and 53.58μg·g-1 respectively, which are almost 1 times to the contrastive one.The protein of selenium-enriched soybean sprouts is isolated by the method of alkali-solution and acid-isolation. The result indicates La can increase Se content and total content of amino acids in proteins extracts, increasing by 12.04% and 2.31% respectively as opposed to control. The content of rare earth La is analyzed. And the data indicates that the contents of rare earth in the samples increase with the increase of the concentration of rare earth added in the cultivation solution. When the concentrations of rare earth Neodymium Magnets added in the soybean sprouts is 7μg mL-1, the highest content of rare earth in the soybean sprouts is 30.35μg·g-1, which is below the tolerable upper intake level of rare earth for adults .Finally antioxidant analysis show that low concentration La could promote proteins to scavenge hydroxyl and superoxide radicals effectively, especially for the superoxide radicals. In general, rare earth La is an effective and safe accelerant for soybean sprouts to absorb Se.