二羟丙酮羰氨反应体系中烷基吡嗪生成规律的研究
Study on the Formation of Alkyl Pyrazine in 1, 3-Dihydroxyacetone Carbonyl Ammonia Reaction System
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摘要: 烷基吡嗪(APZ)是食品的重要风味成分组分,同时也是羰氨反应(美拉德反应)的产物之一。为了探究羰氨反应体系中新的APZ反应模型及模型中烷基吡嗪生成的规律,本文以铵盐与二羟丙酮为底物,研究了铵盐种类、时间、温度、浓度、比例及pH对二羟丙酮产生不同烷基吡嗪化合物(Alkylpyrazine,APZ)的影响规律。以反应APZ生成量为标准,在五种铵盐中,氯化铵与二羟丙酮反应生成APZ含量最高,为(4.59±0.11) mg/L;最适反应时间为15 h,反应浓度为3.7 mol/L,反应比例为1∶1,反应pH为3。以氯化铵与二羟丙酮为反应底物,APZ生成量随着温度的升高而升高;随着反应时间的延长,APZ生成量先上升再下降,其中,2,3,5-三甲基吡嗪与四甲基吡嗪的生成遵循零级反应规律;随着反应浓度的增大,APZ生成量呈现先上升后下降的趋势,固定二羟丙酮浓度,随着氯化铵浓度比例的增高,APZ含量也呈现先升后降的趋势;在弱酸性的环境下,更有利于APZ的生成。Abstract: Alkylpyrazine is an important flavor component of food, and it is also one of the products of carbonyl ammonium reaction. In order to explore the new alkylpyrazine reaction model in the carbonyl ammonium reaction system and the law of alkylpyrazine formation in the model, in this paper, ammonium salts and dihydroxyacetone were used as substrates. The effects of the type, time, temperature, concentration, ratio and pH of ammonium salts on the production of different alkylpyrazine (APZ) from dihydroxyacetone were studied. Taking APZ production amount as the standard, the APZ content was the highest (4.59±0.11) mg/L when ammonium chloride reacted with dihydroxyacetone among the five ammonium salts. Optimum extraction conditions were concluded as follows:Time of 15 h, concentration of 3.7 mol/L, reaction ratio of 1:1, pH of 3.With ammonium chloride and dihydroxyacetone as the reaction substrate, the content of APZ increased with the increase of temperature. With the increase of the reaction time, the content of APZ increased first and then decreased, the formation of 2, 3, 5-trimethyl pyrazine and tetramethylpyrazine follows a zero-order reaction law. With the increase of the reaction concentration, the content of APZ production first increased and then decreased, and the concentration of dihydroxyacetone was fixed, and as the proportion of ammonium chloride concentration increased, the APZ content also showed a trend of rising first and then falling. In a weakly acidic environment, it was more conducive to the formation of APZ.