A kind of thiazole compound with bean flavor and aroma characteristics and preparation method thereof

Abstract

The invention discloses a thiazole compound with bean flavor and aroma characteristics and a preparation method thereof. The molecular structure formula of the thiazole compound is: in the formula, R is formyloxyethyl, acetoxyethyl, formyloxymethyl, acetyloxy Methyl, 2-ketopropionyl or 2-hydroxypropionyl. The preparation method is divided into two steps. First, dilute the mercaptan sample, extract it with double-distilled petroleum ether, combine the petroleum ether layers extracted each time, and concentrate under reduced pressure to obtain the bean fragrance sample A; then add the bean fragrance sample A with dichloromethane Dissolve, evaporate the solvent, and load the sample on a silica gel chromatography column for ordinary silica gel column chromatography separation; use n-hexane-ethyl acetate system as the mobile phase, collect the eluent in the selected interval according to the polarity from small to large, and press Rf Fractions with high purity were combined, and the eluted fractions were concentrated and combined according to the aroma to obtain the part sample B containing bean flavor components; the part sample B containing bean flavor components was purified, concentrated and dried under reduced pressure to obtain the target product.

Description

technical field [0001] The invention belongs to the technical field of chemical industry, and relates to a preparation method of 4-methyl-5-R-thiazole, a characteristic compound of bean flavor and aroma, especially refers to the extraction and separation of 4-methyl-5-R-thiazole, a characteristic compound of bean flavor and aroma, from mercaptan spices. 5-R-thiazole method. Background technique [0002] Thiazole chemical name: 4-methyl-5-(β-hydroxyethyl)-thiazole, referred to as thiol; English name is 4-Methyl-5-beta-hydroxyethyl thiazole referred to as MHT. The FEMA number is 3204. Colorless to light yellow viscous oily liquid, the color becomes dark after long storage. The boiling points are: 135°C / 933.3Pa, 123~124°C / 399.9Pa, 103°C / 133.3Pa. The refractive index is: n D 20 =1.5470, very soluble in water, soluble in ethanol, ether, benzene and chloroform, has an unpleasant smell of thiazole compounds at higher concentrations, but has a pleasant fragrance at extremely lo...

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Problems solved by technology

[0008] 4-Methyl-5-(β-hydroxyethyl)-thiazole is commonly used as a chemically synthesized food flavor. During different processing processes such as preparation and purification, a small amount of different impurities that cause aroma are produced to present a nutty bean aroma, Milk aroma, eggy smell, meat aroma, these trace aroma components are small in content and unknown in structure, so it is difficult to be directly detected and identified by gas chromatography-mass spectrometry GC-MS. For the separation and identification of these aroma-causing impurities in mercaptans It has always been a hot spot in the field of fragrance research. So far, there has been no literature report on the separation of this type of aromatizing component in mercaptans, let alone the chemical structure of this aromatizing component in mercaptans.

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