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The chemical composition of the tobacco leaf directly affect the quality of the tobacco products. Compared to the quality of our tobacco quality tobacco abroad Currently, there are still a wide gap between Hong temperament and tobacco aroma quantity greater difference with foreign tobacco aroma insufficient flue gas due to soft. The flavor precursors because of its tobacco production, stable during storage, and release the aroma in the suction process, you can avoid the loss of aroma and make uniform aroma release. Therefore is the focus of the study of tobacco and flavor of food aroma. This thesis, the ultra-high performance liquid chromatography - electrospray ionization mass spectrometry (UPLC / ESI-MS / MS) of the categories in the tobacco flavor precursors are summarized as follows: (a) using ultra-high performance liquid chromatography - electrospray Ionization Mass Spectrometry (UPLC / ESI-MS / MS), and rapid determination of five aromatic tobacco acid and phenolic acids (benzoic acid, phthalic acid, 4 - coumaric acid, caffeic acid, ferulic acid) were measured The results showed: ① flue-cured tobacco in acid, phthalate, 4 - coumaric acid and ferulic acid content were lower; caffeic acid content is much higher than other aromatic acids and phenolic acids ② flue-cured tobacco, and domestic flue-cured tobacco caffeic acid content greater than foreign flue-cured tobacco: the ③ Yunnan Province, producing flue-cured tobacco phenolic content than other parts of flue-cured tobacco phenolic content. (B) the rapid determination of tobacco glycosidic: ① the use of GC-MS analysis aglycone structure, combined with liquid chromatography mass spectrometry identification of the five kinds of glycosidic; ② summarized glycosidic fragmentation in ESI (-) ion source mode law . (C) 11 kinds of rapid screening and identification of tobacco flavor precursors: (1) using mass neutral loss scan function, screening out 11 kinds of flavor precursors; ② summarized in the ESI (-) ion source mode the fragmentation of the law. (D) the rapid screening and identification of five kinds of tobacco flavonoids: (1) using mass precursor ion scanning function, screening 5 rue sugars flavonoids; ② summarized under the ESI (-) ion source mode The fragmentation of the law. Summarizes several categories flavor precursors cleavage rule: (1) organic acids, flavor precursors will fracture obtaining characteristics acid, then lost-COOH, such as p-coumaric acid derivatives will be cleaved to generate the coumaric acid fragments 162.8, 118.9 fragment ions lost-COOH; ② single-glucoside glucoside bond at fracture, glycosylation fragments of 163, and aglycone [M-162] - bioside will produce two glycosylated fragment ions 296, and sugar The base 163 and [M-295] -; ③ flavonoids in ESI positive and negative ion mode, aglycone and sugar fracture to produce sugar 309 and sugar with Na combined to produce 331 fragment ions and aglycone ion and its combination with Na ion. Flavor precursors plant metabolites, most difficult to obtain standard, its research as part of the standard organic acids and flavonoids. Through the UPLC-MS/MS the neutral loss scanning ion scan before, the screening of 20 tobacco flavor precursors, several flavor precursors in two MS scan mode ESI ion source and Fracture law summarized. The two fragments of mass spectral library established part of the flavor precursors, and tobacco upper, middle, lower leaves flavor precursor substance content were compared using semi-quantitative. These efforts will help to understand the differences of the various tobacco flavor precursors, liquid chromatography-mass spectrometry analysis of flavor precursors lay the foundation for future use.
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