Determination Of Chemical Composition And Tea Making Process Of T.miqueliana Flower Based On Metabolomics

mia miqueliana Maxim.is in Malvaceae family,Tilia Linn.genus,also known as the linden tree,which is endemic to China.T.miqueliana flower and bark can be used for medicine,is an ancient folk medicinal tree species,inflorescence infusion has calming,sweating,antispasmodic and antipyretic effects;The stem bark is mainly used to treat symptoms such as initial onset of fatigue and long-term cough,with high utilization value and broad promotion prospects.Pharmacopoeias such as "Medicinal Botany","Chinese Medicinal Plant Guide","Zhejiang Tianmu Yam Plant History"and other pharmacopoeias have introduced its medicinal effects,but the specific ingredients and medicinal health effects of T.miqueliana flower have not been reported in relevant literature.First.Based on non-targeted metabolomics to determine the chemical composition and content of T.miqueliana flower,a total of 118 chemical components of 22 categories,such as organic acids and amino acids,were identified with a relative content of ≥0.1%,and the relative total content is 93.35%.Systematic and in-depth chemical composition and pharmacological research on T.miqueliana flower was carried out,and the ingredients with medicinal health care effects on the human body were screened,and the material basis of the medicinal health care effects of T.miqueliana flower was further clarified.Among them,102 substances have good medicinal health care effects on the human body,and the relative total content is 83.79%,accounting for 89.76%of all metabolites,all of which are harmless to the human body and have good research value.Second.T.miqueliana tea production technology research1.The influence of different fixation methods on the quality of T.miqueliana teaIn this study,steaming,microwave fixing,and blanching were used to fixation T.miqueliana flower,and after comprehensive comparison sensory quality evaluation,the quality of T.miqueliana tea with microwave power of 500 W and 60 S is the best quality,which is the best fixation method.2.The three drying methods of hot air drying,microwave drying and vacuum freeze drying were adopted to dry the fixation T.miqueliana flower,and the best drying method of T.miqueliana tea is determined by sensory evaluation and the content of physical and chemical substances and water extracts in tea soup,which provided scientific basis and new direction for the development of T.miqueliana tea.In terms of quality,T.miqueliana tea sublimated for 15 h at-12℃ and resolved for 18 h vacuum freeze drying at 5℃ had the best quality,high drying rate,and better maintained the natural form of flower,good color and aroma.However,from the comprehensive consideration of production cost,tea soup physical and chemical substances content,the 60℃ hot air drying method is more suitable for large-scale production,the production cost performance is high,and the quality of T.miqueliana tea is also better.Third.Identification of the different components of T.miqueliana tea and flowerThis study is non-targeted metabolomics was used to screen and mensuration the differential components and contents of T.miqueliana tea and T.miqueliana flower,and 55 different metabolites in 18 categories,including organic acids,flavonoids and amino acids,were identified by liquid chromatography mass spectrometry(LC-MS)from T.miqueliana tea and flower.Among them,27 kinds of ingredients were adjusted upwards and 28 kinds of ingredients were adjusted downward.Amino acids and nucleotides were raised with large upregulation amplitudes,among which O-acetyl-L-serine and deoxyuridine the upward revisions were 4.28%and 3.58%,respectively.Flavonoids and organic acids were more regulated,among which desmethyl gentianone and vanillic acid were lowered by 4.58%and 4.06%,respectively.The reason for the difference in composition may be that organic acids and flavonoids are sensitive to heat and are easy to decompose during the tea making process,resulting in a decrease in the content of hot air drying tea organic acids and flavonoids;Proteins are hydrolyzed at high temperatures during the tea making process to generate amino acids and nucleotides,thereby increasing the content of amino acids and nucleotide compounds in hot air drying tea.This study aims to rationally develop T.miqueliana tea products in the form of health scented tea,so as to provide a basis for the standardized and large-scale production of T.m iqueliana tea,so as to improve the utilization value of T.miqueliana flower.