Study On The Formming Mechanism Of Aroma Quality During Processing Black Tea

Black tea aroma is one of the key indicators to evaluate the quality of tea, t he current researchmainly focuses on the analysis of main aroma components o f black tea, black tea processingin a process of aroma quality influence, the process ing of raw materials a class of substances involved in or affect the aroma qualit y and aroma precursors formation etc, and Seldom see study the mechanism of ch anges and quality of aroma the dynamic formation of the whole process in the p rocessing of black tea. This study takes Taoyuan tea leaf as material, using the trad itional processing technology of black tea and multi sampling method, dynamic ch ange on aroma quality components of black tea in the processing of dynamic cha nges and its related substances glycosides, fatty acids, amino acids, beta carotene a nd other substances,in-depth study of the red tea the gas products associated wit h the relationship between the formation of matter, preliminary clarify the aroma quality of black tea in the process of forming mechanism. The main results are a s follows:(1) The Taoyuan tea leaf processing of black tea, detected a total of 110 aro ma components,the main group of high content divided into 22 kinds, including 9 kinds of alcohols,3 kinds offatty acids,5 aldehydes,3 lipids,2 kinds of ketone s, fresh leaves, withering leaves, rolling leaves,fermenting leaves, drying leaves we re 66,69,77,79,71 kinds of aroma components.During the withering, alcohol, lipi d aroma contentsincreased; during rolling, alcohols,aldehydes, ketones, lipid content i ncreased; during fermentation, alcohols, aldehydes,ketones relative content increase d, while the relative content of esters decreased,hydrocarbon and acid relative cont ent decreased slightly dry; during the period, the relative content of various substa nces decreased. The 22 main aroma components, neroli, Ye Lvchun, Shun-2-pente ne-1-alcohol, nerolidol, benzyl alcohol, benzyl alcohol, alpha methylvinyl-5-thre e-5-four-2-methanol, methanol benzene hydrogenation of furan, geraniol,hexana 1, (E) the relative content of-2-hexenal, incense Methylis salicylas, folic acid, pal mitic acid methyl ester from start to withering before fermentation in later perio d, gradually increased, and then decreased; the relative content of palmitic acid, li noleic acid fron the beginning to the end of the dry withering, decreased; benzenea cetaldehyde, CIS-7,10,13-sixteen carbon three aldehydes from beginning to dry wit hering the end, increased.(2) The GC/MS analysis showed that, the Taoyuan leaves in the processing of black tea, mainly linalool, geraniol, benzyl alcohol, geraniol Methylis salicyla s, there are 5 kinds of glycosidic aroma substances, including free aroma compone nts in the withering,rolling, fermentation, the relative content increased graduall y, and in dry, the relative content decline rapidly; bound aroma components showe d a gradual downward trend. A good relationship of bonding aroma components d ecreased with the relative content of free aromacomponents relative content increa sed and the change trend of beta glucosidase enzymeactivity decreased and glycos ides decreased.(3) In the processing of black tea, glutamic acid, arginine, theanine three ki nds of amino acids content decreased gradually, leucine gradually increased, while the other 14 kinds of amino acid components increased first and then decrease d; the total amino acids in the total amino acids after drying than fresh leaves deer eased by 29.40%; the change of amino acid composition on the one hand, wither ing, rolling, fermentation period because the catechinoxidation products of o-quino ne under the catalysis of Strecker degradation and the mainaroma formation qualit y components of benzaldehyde, benzene acetaldehyde, on the other hand is due t o the Maillard reaction of amino acid in dry period mainly generate aroma quality components methylpyrazine,2-pentyl furan; dynamic change correspondence betw een the two has good relationship.(4) Link with black tea in the process of the formation of aroma quality of fatty acids related mainlypalmitic acid, linoleic acid, linolenic acid, twenty-eight ac id, behenic acid and stearic acid six kinds of fatty acids. In addition to witherin g stearic acid, the other 5 kinds of fatty acidsdecreased by 10.71%, and(Z)-3-he xenal, (E)-2-hexenal,-2-, CIS pentene aldehyde has-1-alcohol and 3 kinds of este rs (Methylis salicylas, adjacent benzene two formic acid two,isobutyl methyl palm itate) aroma quality component relative content was increased, the totalincrease of 40.80%. Rolling, fermentation stage, except stearic acid, the other 5 kinds of fatt y acid content decreased continuously, and the relative content of aroma quality of theassociation increased sharply, especially the rolling stage of growth in the a mount of 148.60%. Due to the influence of high temperature drying stage,6 kin ds of fatty acids andaroma ingredients content association decreased, and the total amount of fatty acidsdecreased 26.70%, a decrease of 41.40% of total aroma co mponents.(5) In the processing of black tea, beta carotene content was decreased gra dually, the relative content of aroma components and related beta produced by the degradation of Iononeshowed a gradually increasing trend, through the processing of black tea, beta carotene content from fresh tea leaves began to wither When wi It 0.68% down to dry at the end of the 0.20%, and the relative content of beta io none from start withering 0.35% increase to dry at the end of the 1.29%, that the beta carotene content decreased and aroma quality components betalonone relative c ontent increased with better coupling relationship.