Amino Acid Analysis And Spectroscopic Study Of The Effect Of Sodium Selenite On The Root Of Moringa Oleifera Lam.

Selenium?Se?was considered to be a beneficial element.Deficiency of Se will lead to malnutrition and induce liver disease.Se deficient crops are common.Increasing the content of Se that can be absorbed by human body in food will become an important direction of the development in modern agriculture.Moringa oleifera was an angiosperm with high nutritional value.It is rich in mineral elements,amino acids and antioxidant substances.Therefore,Moringa oleifera can be used as a functional health food.Na₂SeO₃ is applied through the soil to achieve the purpose of bio-enhancement of Se in root of Moringa oleifera.In this paper,Na₂SeO₃ was applied to the soil to cultivate Moringa oleifera.The effects of different concentrations of Na₂SeO₃ on elements,amino acids and proteins in roots of Moringa oleifera were studied by inductively coupled plasma atomic emission spectrometry,ninhydrin colorimetry and combustion.The mechanism of the effects of Na₂SeO₃ on the components of the roots of Moringa oleifera was studied by Fourier transform infrared?FTIR?spectroscopy,in order to provide scientific basis for the roots of Moringa oleifera to be used as Se-fortified products.The results of the paper show that:?1?Compared with the control group,the Moringa oleifera root cultivated with exogenous Se increased Se by 42⁴15%.The accumulation of Se in Moringa oleifera root was the highest when Na₂SeO₃ was added near 4.0 mg/kg.When Na₂SeO₃?0.5mg/kg was cultivated,the accumulation of K was decreased.When Na₂SeO₃>0.5mg/kg was added,the concentration of K in the roots of Moringa oleifera increased by 0.49¹47.92%compared with the control group;The content of Mo decreased by 24.73⁷9.52%when exogenous Se was added.When Na₂SeO₃?0.3mg/kg was added,the concentration of Mo increases with Na₂SeO₃;When Na₂SeO₃ was added in the range of 0.3¹.5 mg/kg,the concentration of Na decreased with the increase of the addition amount.When Na₂SeO₃ was added in the range of 1.5⁶.0 mg/kg,the concentration of Na increases with Na₂SeO₃;When Na₂SeO₃<1.0mg/kg,the concentration of P decreases with the addition of Na₂SeO₃.When Na₂SeO₃ was added in the range of 1.0⁶.0 mg/kg,the concentration of P increases with Na₂SeO₃;The application of exogenous Se can significantly reduce the accumulation of Zn in the roots of Moringa oleifera,which is 30.76⁵3.89%lower than that of the control group.?2?The addition of exogenous Se can significantly affect the absorption of potentially harmful elements in the root of Moringa oleifera.The addition of Se made Moringa oleifera root inhibit the absorption of Cd,Cr and Ni.When 2.0mg/kg was added,the inhibition effect on Cd and Cr was the best,with the reduction of 81.89%and 64.02%,respectively;The reduction of Ni was in the range of 18.22⁵7.73%;When the concentration of Na₂SeO₃<1.0mg/kg was added,it had no inhibitory effect on Hg.When exogenous Se was 1.0⁶.0mg/kg,the range of Hg concentration decreased was 43.45⁶7.71%compared with the control group;Adding exogenous Se in the range of 0.3⁶.0mg/kg,compared with the control group,the content of Pb decreased by 7.02⁵7.67%.?3?The FTIR spectra of Moringa oleifera root was mainly composed of the characteristic peaks of hemicellulose,lignin,calcium oxalate,protein and polysaccharide.The carboxylate,phosphate,hemicellulose and protein in Moringa oleifera roots were changed by cultivating Moringa oleifera with different concentrations of exogenous Se.PLSR analysis was performed for Se,Cd,Mg,Mn and Mo by FTIR spectra,the regression determination coefficients were 0.7479,0.9181,0.8585,0.9164 and 0.7884,respectively.Tthe concentration of Se in Moringa oleifera root was related to hemicellulose,protein,polysaccharide and lignin,Mg was mainly related to protein,Mn was related to hemicellulose and protein,and Mo was related to hemicellulose,protein and lignin.?4?The cultivation of Moringa oleifera by adding Na₂SeO₃ can significantly reduce the content of non-essential amino acids,total amino acids and protein in the root of Moringa oleifera.The first limiting amino acid in Moringa oleifera root was Met+Cys,and the SRCAA values are all greater than 70.The SRCAA value of Moringa oleifera root can be increased by adding exogenous Se,and the increase was in the range of 4.24%to 30.95%.The results showed that exogenous se changed the carboxylate,phosphate,hemicellulose,lignin and protein in the roots,which can increase the accumulation of Se in the root while changing the content of mineral elements and inhibiting the absorption of potentially harmful elements.Therefore,the roots of Moringa oleifera are expected to become Se enriched fortified food.