反应条件对葡萄糖-甘氨酸美拉德反应体系中糠醛类化合物形成的影响

Effects of Reaction Conditions on the Formation of Furfural Compounds in Maillard Reaction System of Glucose-Glycine

为了分析美拉德反应体系中糠醛类化合物的形成规律,本研究构建了葡萄糖-甘氨酸反应体系,探究了反应物配比、体系初始pH、加热时间和温度对5-羟甲基糠醛(5-Hydroxymethylfurfural,HMF)、2-糠醛(2-Furfural,F)和5-甲基糠醛(5-Methyl-2-furfural,MF)形成的影响,并分析了它们的形成动力学,预测了它们的表观活化能。结果显示:葡萄糖与甘氨酸的摩尔浓度比对糠醛类化合物的生成量有较大影响。HMF生成量随着摩尔浓度比的增大而持续增加,而F与MF的生成量在摩尔浓度比为1:1时达到最高值;酸性pH条件有利于HMF的形成,中性和碱性pH条件有利于F的形成,糠醛类化合物生成总量随着pH的增加而迅速减少;随着加热温度升高、加热时间延长,HMF、F和MF的生成量均逐渐增加;HMF和F的形成在温度较低时符合一级动力学模型(HMF:70~110℃;F:70℃),在温度较高时符合零级动力学模型(HMF:130℃;F:90~130℃);MF的形成符合零级动力学模型(90~130℃)。本研究可对食品热加工过程中HMF、F和MF的生成和控制提供理论指导。

The Maillard reaction system of glucose and glycine was applied to study the formations of furfural compounds.The effects of glucose/glycine molar concentration ratio,initial pH,heating temperature and time on the formations of 5-hydroxymethylfurfural(HMF),2-furfural(F)and 5-methyl-2-furfural(MF)were evaluated.The kinetic equations of HMF,F and MF were established and their apparent activation energies were also predicted.The results showed that:Glucose/glycine molar concentration ratio had great influence on the formations of furfural compounds.The formation of HMF continued to increase with the increase of ratio,and the formations of F and MF reached the maximum when the ratio was 1:1.The acidic pH conditions could promote the formation of HMF,while the neutral and alkaline pH conditions were conducive to the formation of F.The total amount of furfural compounds decreased rapidly with the increase of pH.The amounts of HMF,F,and MF in the glucose-glycine reaction system increased with the increase of heating temperature and time. The formations of HMF and F in glucose and glycine model followed first-order kinetics model at lower temperatures (HMF: 70~110 ℃;F: 70 ℃), while their formations were in accordance with zero-order kinetics model at higher temperatures (HMF: 130 ℃;F: 90~130 ℃). The formation of MF followed zero-order kinetics model at 90~130 ℃. The results would provide guidance on the production and control of HMF, F, and MF in the food thermal processing industry.