Department of Environmental Toxicology, University of California, Davis, California 95616, United States.
J Agric Food Chem. 2013 Jul 17;61(28):6865-72. doi: 10.1021/jf401958w. Epub 2013 Jul 8.
Glyoxal, methylglyoxal, and diacetyl formed from sucrose alone and from a D-glucose/ammonia Maillard model system were analyzed by gas chromatography. They are known as precursors of 4(5)-methylimidazole (MI). Glyoxal and methylglyoxal formed more in acidic conditions than in basic conditions, whereas diacetyl formed the most at the highest basic condition of pH 12. Glyoxal formation from sucrose ranged from 0.33 to 32.90 μg/g under four different time and temperature conditions. Amounts of glyoxal, methylglyoxal, and diacetyl formed in Maillard model systems ranged from 2.98 to 46.12 μg/mL, from 8.27 to 156.61 μg/mL, and from 14.94 to 1588.45 μg/mL, respectively. 4(5)-MI formation in the same model systems ranged from 28.56 to 1269.71 μg/mL. Addition of sodium sulfite reduced formation of these chemicals significantly. Total α-dicarbonyl compounds in 12 commercial soft drinks ranged from 5.75 to 50.72 μg/mL. 4(5)-MI was found in levels ranging from 1.76 to 28.11 ng/mL in 10 commercial soft drinks.
仅由蔗糖和 D-葡萄糖/氨美拉德模型体系形成的乙二醛、甲基乙二醛和双乙酰通过气相色谱法进行了分析。它们是 4(5)-甲基咪唑（MI）的前体。乙二醛和甲基乙二醛在酸性条件下比在碱性条件下形成更多，而双乙酰在 pH 值为 12 的最高碱性条件下形成最多。在四种不同的时间和温度条件下，蔗糖形成的乙二醛范围为 0.33 至 32.90μg/g。美拉德模型体系中形成的乙二醛、甲基乙二醛和双乙酰的量分别为 2.98 至 46.12μg/mL、8.27 至 156.61μg/mL 和 14.94 至 1588.45μg/mL。同一模型体系中 4(5)-MI 的形成量为 28.56 至 1269.71μg/mL。亚硫酸钠的添加显著降低了这些化学物质的形成。12 种商业软饮料中的总α-二羰基化合物含量为 5.75 至 50.72μg/mL。在 10 种商业软饮料中发现 4(5)-MI 的含量范围为 1.76 至 28.11ng/mL。
