Aussenac T, Lacombe S, Daydé J
Laboratoire d'Agrophysiologie, ESA Purpan, Toulouse, France.
Am J Clin Nutr. 1998 Dec;68(6 Suppl):1480S-1485S. doi: 10.1093/ajcn/68.6.1480S.
Soybean isoflavones (genistin, daidzin, glycitin, and their malonyl forms and aglucons) are thought to be responsible for the astringent taste of soyfoods. Generally, HPLC with a methanol and water elution gradient is used for isoflavone quantification, but capillary zone electrophoresis (CZE) has been used more recently to separate several flavonoids in plant extracts. We present the results of CZE analysis of isoflavones in soybean extracts. Conditions for separation by using CZE were optimized for analysis of soybean isoflavones. We compared the results of extraction at different temperatures and with different compositions of solvent. Total extraction of isoflavones was not affected by temperature but was affected by composition of the solvent. Malonyl forms of isoflavones were thermally unstable. We analyzed the isoflavone content of different varieties of soybean seeds sown on different dates. Total isoflavone content varied among different varieties and with sowing dates. Interactions between the variety and the sowing date also affected isoflavone composition. We conclude that the variety of soybean seed and environmental growing conditions, such as sowing date, can contribute to seed quality by reducing its isoflavone content, modifying its isoflavone composition, or both.
大豆异黄酮（染料木苷、大豆苷、黄豆黄素及其丙二酰化形式和苷元）被认为是大豆食品产生涩味的原因。一般来说，采用甲醇和水梯度洗脱的高效液相色谱法用于异黄酮定量分析，但最近毛细管区带电泳（CZE）已被用于分离植物提取物中的几种黄酮类化合物。我们展示了大豆提取物中异黄酮的毛细管区带电泳分析结果。通过毛细管区带电泳进行分离的条件针对大豆异黄酮分析进行了优化。我们比较了不同温度和不同溶剂组成下的提取结果。异黄酮的总提取量不受温度影响，但受溶剂组成影响。异黄酮的丙二酰化形式热不稳定。我们分析了在不同日期播种的不同品种大豆种子的异黄酮含量。不同品种以及不同播种日期的总异黄酮含量各不相同。品种与播种日期之间的相互作用也会影响异黄酮的组成。我们得出结论，大豆种子的品种以及环境生长条件，如播种日期，可通过降低异黄酮含量、改变异黄酮组成或两者兼而有之来影响种子质量。
