| Nitrate and ammonium nitrogen is absorbed by plants use both the main nitrogen forms, tea is one kind of consumption of the high nitrogen plants, nitrogen directly or indirectly affect the metabolism and growth and development of the tea. Nitrogen affects not only the physiological characteristics of tea, but also affect the quality of ingredients in tea.Nitrogen is the protein, amino acids, chlorophyll and many other important organic composition.Nitrogen compounds on the quality of tea, amino acids, caffeine, water extract is equal to the color of tea, soup, taste is proportional to the This article studies the impact of different nitrogen forms on nitrogen metabolism in the active chemical components of fresh tea leaves to clarify the formation mechanism of the quality of fresh tea leaves, tea and correct fertilization and fresh leaves of quality regulation contribute to the use of modern biotechnology.Subject to varieties of tea Longjing43as experimental material, respectively, for the ammonium, nitrate, total nitrogen, nitrogen-free to deal with tea tree, and then collecting the tea leaves of different developmental stages of a bud, a bud and two leavesa clover bud and function of leaf and root tissues and save-80℃ultra-low temperature refrigerator, and then create a technology platform for sample preparation and analytical analysis of the metabolic spectrum. Preparation of aqueous extract samples, the aqueous extract material injection before derivatization. Then analysis of samples using gas chromatography-mass spectrometry technique (GC-MS), GC-MS analysis, structural analysis of various metabolites in the map based on the NIST and Wiley databases; the GC-MS spectra in order to filter noise, normalization, baseline calibration and peak matching process, the principal component analysis (PCA) and partial Least Squares (PLS) for data processing; formation of different nitrogen forms on the quality of nitrogen metabolism in fresh tea leaves at different growth stages during the mutual differences. Dynamic changes in monitoring different growth stages of fresh tea leaves samples of amino acids, catechins, alkaloids and flavonoid composition and its content.The experiment has achieved the following main results:Tea aqueous extract of the metabolic spectrum analysis technology platform, and the tea water phase for the test samples for GC-MS analysis. The results show that tea aqueous extract various peaks to distinguish between good, basic baseline separation. Metabolites in the spectra of each of retrieval and identification of the NIST mass spectrum database124from the isolated peak of the ChineseCommunists identified101peaks have been identified compounds, the total ion outflow peak area of99.17%. Tea aqueous extract of the main ingredients for the organic acids, sugars, sugar alcohols, glycosides, which hydroxybutyricacid (10.71%), glucoside (6.83%), D-fructose (4.82%),2-valerate (2.94%), L-proline (2.93%), succinic acid (2.81%). erythritol (2.58%), higher content of serine (1.41%), fresh tea leaves in addition to detect contains a lot of isocitrate(4.06%), but also contains acetic acid (0.51%), ribose (0.17%), acid (0.03%) micro-organic acids such as mandelic acid; alcohols were also detected a trace of arabinose alcohol (0.024%), ribitol (0.07%), phytol (0.06%); glycosides were also detected in addition to more outside glucosidase to a small amount of D-pyran-mannosidase(0.03%).Tea water phase extraction material by GC-MS detection data carried out PCA and PLS analysis, The different nitrogen form (of NH4+, of NO3+, NH4+and NO3-and no nitrogen) processing the sample can be carried out better distinction, that the test ofof tea samples of non-volatile substances difference; the same nitrogen forms different growth stages of the tea sample point concentration better. Deal with the same nitrogen forms in fresh tea leaves aqueous extract of multivariate statistical analysis analysis, the different growth stages of fresh tea leaves sample can be clearly differentiated. |
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