Study On Determination Method Of Polyphenols And Amino Acids And Quality Analysis Of Highland Barley

Highland barley is the largest quality grain crop in the plateau region of China,which is rich in nutrients and functional components.The content of polyphenols and amino acids is an important index to evaluate the quality of highland barley,but there is no standard method to detect the content of phenols and amino acids in highland barley at present,and the evaluation system of the nutritional composition of highland barley samples is not mature.Therefore,in this study,crude protein,crude fat,crude fiber,?-glucan,amylopectin,amylose,total starch,amino acids and polyphenols were used as evaluation indexes on the basis of establishing the detection method of polyphenols and amino acids in barley grains from different habitats.Principal component analysis and cluster analysis were used to evaluate the quality of barley in different regions.The main results are as follows:1.A high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS)method was developed for simultaneous determination of 24 polyphenols in barley grains.The method could detect 24 kinds of polyphenols within 35 min,and the correlation coefficient r was greater than 0.9912 in the range of 0.2-5.0 mg/L.The methodological evaluation showed that the recoveries of the method were 68.76-117.12%at a certain addition level.It can be used for the detection of polyphenols in highland barley and other agricultural products.2.A high performance liquid chromatography-tandem mass spectrometry(LC-MS/MS)method was developed for simultaneous determination of 13 amino acids in highland barley kernel.Methods 13 kinds of amino acids were separated within 15 min in the range of 1.25-65 nmol/m L with correlation coefficient R > 0.9901.The recoveries were 76.43-101.39 % with RSD?12.12 %.This method overcomes the derivatization of traditional methods and meets the requirements for the determination of 13 amino acids in highland barley kernel.3.From the above mentioned methods of Tibet,yunnan,qinghai,sichuan and gansu highland barley polyphenol compounds and amino acids were tested analysis,the results showed that different areas of highland barley ferulic acid content were the highest,but there is no significant difference between resveratrol,epicatechin,amino acid in the highland barley is given priority to with glutamic acid,arginine,content is higher,There was no significant difference in glycine,tyrosine,phenylalanine and leucine.The 44 quality indexes of highland barley were analyzed by principal component analysis,and 7principal factors were obtained,whose cumulative variance contribution rate was70.414%.The comprehensive evaluation function was used to evaluate and analyze the highland barley samples.Through cluster analysis,five quality indexes,including lysine,vanillin,p-coumaric acid,?-glucan and amylopectin,could be used as important indexes to evaluate the grain quality of highland barley.