Introduction | aroma is one of the important quality characteristics of aromatic rice. Aromatic rice contains more than ordinary rice an aromatic flavor similar to the popcorn or Jasmine type. As fragrant rice is very popular, it is in short supply in the world rice market. These make the study of Rice aroma components have very important value in Theory and Application. The main component of aromatic rice aroma is volatile, oxidized 2-acetyl-1-Pyrroline. |
preparation | synthesis of 2-acetyl-1-pyrroline, comprising the following steps: 1) the pyrrolidine-2-carbonitrile hydrochloride is dissolved in an inorganic alkaline solution for neutralization reaction, extracted several times with an organic extractant, the organic layer is combined, and then a desiccant is added to the organic layer to dry, dehydrate, and filter, the volatile components in the filtrate are removed to obtain an intermediate product; The pyrrolidine-2-carbonitrile hydrochloride is (S)-pyrrolidine-2-carbonitrile hydrochloride or (R)-Pyrrolidine-2-carbonitrile hydrochloride or a mixture of two isomers of (S)-pyrrolidine-2-carbonitrile hydrochloride and (R)-pyrrolidine-2-carbonitrile hydrochloride in any proportion; that is, the starting material is the S-configuration raw material or the R-configuration raw material or a mixture of the S-configuration raw material and the R-configuration raw material in any proportion. The inorganic alkaline solution is at least one of potassium carbonate solution, potassium bicarbonate solution, sodium carbonate solution and sodium bicarbonate solution; The concentration of the alkaline solution is 10-50wt%. 2) dissolve the intermediate product obtained in the previous step in an organic solvent, Dropwise add tert-butyl hypochlorite for halogenation reaction, then add potassium tert-butoxide for elimination reaction, filter, then the volatile components in the filtrate are removed to obtain pyrroline-2-carbonitrile; 3) dissolve pyrroline-2-carbonitrile in organic solvent, add Grignard reagent for Grignard reaction, add acid solution for hydrolysis, then extract several times with organic extractant, combine organic layer, the organic layer was dried and dehydrated by adding a drying agent, filtered, and the volatile components in the filtrate were removed to obtain a product. |
Application | 2-acetyl-1-pyrroline, abbreviated as 2AP,IUPAC name 1-(3, 4-dihydro-2h-pyrrol-5-yl) ethanone, an aromatic compound and flavor that provides white bread, jasmine rice and fragrant rice, and spice broccoli and the habitual odor of bread flowers (mallaris Glara). Many observers describe this smell as similar to "hot, buttered popcorn" and release it into the smell of the urine of a bear (PANDA). |
detection | polydiallyldimethylammonium chloride (PDDAC) was prepared by physical impregnation-SPME solid phase microextraction head, and coupled with gas chromatography (GC) for the selective adsorption of 2-AP in rice. The adsorption of 2-acetylpyrroline in rice by Nafion and polydimethyldiallylammonium chloride (PDDAC) modified capillary was studied by gas chromatography. The experimental conditions such as desorption temperature and desorption time were optimized, and the linear range of target molecule was 0.50-8.00 ng/mL, the detection limit of the method was 0.10 ng/mL. The experimental results were applied to the actual determination of two batches of rice samples. |