Analysis On Characteristics And Bioactivity In Se-enriched Grape

As a trace element that is rare but essential in nature,selenium,is of great significance to living things worldwide.Selenium-enriched food is a convenient and effective method to directly supplement selenium in human body and use exogenous selenium fertilizer to cultivate selenium-enriched crops.Plants can effectively convert selenium into organic selenium compounds through self-growth metabolism and absorption.In this study,soil selenium-enriched grape was used as a research sample to study the effect of selenium on grape absorption and transformation and its biological activity.The method of microwave sealed digestion-hydride generation atomic fluorescence spectrometry?HG-AFS?was used to analyze the selenium in selenium-enriched grapes.UV-visible spectroscopic spectroscopy?UV?was used to study the anti-oxidation and scavenging activities of selenium-containing compounds such as selenoprotein and selenium polysaccharide in selenium-enriched grapes.Inductively coupled plasma mass spectrometry?ICP-MS?was used to study selenium.Promotion or antagonism of 16 elements such as iron?Fe?and calcium?Ca?in grapes;high performance liquid chromatography-mass spectrometry?HPLC-ESI-MS?combined technique for selenium and selenium in selenium-rich grapes Different forms were analyzed.The results are as follows:1.Within the range of soil spraying selenium fertilizer?20 mg/L-200 mg/L?,there was no poisoning,indicating that the amount of selenium was in the tolerance range of grapes.In this study,the microwave sequestration digestion and HG-AFS technology were used to analyze the total selenium content in selenium-enriched grapes.The results showed that the total selenium content in the grapes was165.64-480.32 ug/kg,which was 22-67 times that of the control group,indicating that the grapes could effectively enrich the inorganic selenium fertilizer applied to the soil.2.Select ultra-pure water,HCl,NaOH,NaCl,PBS and Tris-HCl as extracting agent to analyze the soluble selenium in selenium-enriched grapes,and obtain the distribution of different dissolved selenium in selenium-enriched grapes:NaOH State>HCl state>H₂O state>NaCl state>Tris-HCl state>PBS state,the selenium migration and transformation ability and the selenium absorption and utilization of the grape in the alkali-soluble state were obtained.3.The optimal conditions for obtaining soluble protein in selenium-enriched grapes by single factor experiment are:NaOH concentration of 0.1 mol/L,ratio of material to liquid of 1:15,extraction time of 90 min,and extraction temperature of40?.Under the optimal conditions,the highest soluble protein content in selenium-enriched grape was 160 mg/L,and the soluble protein content in the sample was 16.78 mg/g.When the concentration of selenium was increased,the selenium content of selenium-enriched grape protein also increased,with a maximum of 44.14ug/kg.4.The optimal conditions for obtaining soluble polysaccharides in selenium-enriched grapes by single factor experiment are:ratio of material to liquid1:20,extraction time of 90 min,extraction temperature of 75?.Under the optimal conditions,the highest soluble polysaccharide content in the selenium-enriched selenium-enriched grape was 160 mg/L,and the soluble polysaccharide content was455.92 mg/g.The results showed that when the selenium gradient was applied,the polysaccharide selenium in the selenium-enriched grape also increased.When the amount of selenium applied was 200 mg/L,the maximum selenium content of the polysaccharide reached 134.50 ug/kg,and the distribution of polysaccharide selenium in the sample was excellent.For protein selenium.5.In the experimental concentration range,the selenium binding ability and reducing power of polysaccharides in selenium-enriched grape were higher than that of selenoprotein,and selenium polysaccharide and selenoprotein were at the maximum when the selenium gradient was 160 mg/L.It has obvious guiding ability to produce selenium-enriched grapes with antioxidant activity,and the reducing ability of selenium polysaccharide in grape is obviously better than that of selenoprotein.6.Quantitative analysis of 16 elements in selenium-enriched grapes by ICP-MS.It is found that 16 elements in different selenium-rich gradient samples show their respective trends.With the increasing concentration of selenium,the biological effects of Cu,Mg,Cr and Hg elements are not obvious;the contents of Mo,V,Mn,Zn and Ca are promoted;the selenium is heavy metal elements such as Co,Ag,As and Pb have significant inhibitory effects.7.Analytical and quantitative analysis of organic selenium and inorganic selenium in selenium-enriched grapes by HPLC-ESI-MS.The conditions for enzymatic hydrolysis of selenoprotein in the grape are optimized to obtain a selenoamino acid.The MRM mode was selected for monitoring,and the results showed that a large amount of selenoamino acids existed in the selenium-enriched grape.In the experimental range,the content of seleno amino acids in selenium-enriched grapes showed an upward trend,and was the highest when the concentration of selenium was 160 mg/L.The peaks of SeCys₂,Se-Met and Se-MeSeCys were 4.52,16.51,3.87 ug/kg,respectively.Inorganic selenium is not present in selenium-enriched grapes.It shows that grape can absorb selenium from the soil where selenium fertilizer is applied and convert inorganic selenium into non-toxic organic selenium through its own metabolic mechanism.Therefore,it is safe and reliable to use selenium-enriched grape as daily selenium supplement.