反应条件对葡萄糖-甘氨酸模拟美拉德反应体系中α-二羰基化合物生成的影响

Effects of reaction parameters on the formation of α-Dicarbonyl compounds in Glucose-Glycine Maillard chemical model system

采用邻苯二胺（OPD）衍生和HPLC定性定量考察了反应条件（温度、p H、时间和底物浓度比）对葡萄糖-甘氨酸模拟美拉德反应体系中三种α-二羰基化合物3-葡萄糖醛酮（3-DG）、乙二醛（GO）和丙酮醛（MGO）生成的影响。结果表明：在80~140℃范围内温度的升高会促进体系中MGO和GO的生成,而3-DG在温度达到110℃时达到峰值,随后则开始下降。p H在5~9范围内对三种物质的影响趋势和温度类似,MGO和GO的生成随p H的升高而不断增加,而3-DG在p H为6时含量达到最高,随后急剧降低。3-DG和GO生成的速率随着时间的延长逐渐降低,而在2 h内MGO的生成速率则趋于恒定。葡萄糖的相对含量升高有利于3-DG的生成,而当甘氨酸的相对含量较高时则会促进MGO和GO的生成。本研究能够为美拉德反应中以α-二羰基化合物为中间产物的风味物质的生成机制研究提供一定的实验依据。

Derivatization with o-phenylenediamine（OPD） as well as qualitative and quantitative analysis with HPLC were employed to investigate the effects of reaction conditions（temperature,p H,duration and reactant ratio） on the formation of three α-dicarbonyl compounds including 3-deoxyglucosone（3-DG）,glyoxal（GO）and methylglyoxal（MGO） in glucose-glycine maillard chemical model systems. The results showed thatthe increasing of temperature promoted the generation of MGO and GO within 80~140 ℃,while the level of 3-DG increased to the highest at 110 ℃,and decreased subsequently. The effects of p H value within 5 ~9 were similar to that of the temperature：the formation of GO and MGO increased with the increasing of p H values,while the levels of 3-DG increased to the maximum as p H vaue of 6. The rate of 3-DG and GO formation decreased as the extension of duration,but it tended to be constant for MGO within 2 h. In terms of the substrate ratio,the formation of 3-DG could be enhanced by the increasing of relative content of glucose,while increasing of glycine levels could promote GO and MGO formation. The results may provide experimental basis to certain extent for flavor compounds with α-dicarbonyl compounds as intermediate products.