Dept. of Food Science and Technology, Ewha Womans Univ., Seoul 120-750, Korea.
J Food Sci. 2010 Oct;75(8):C659-66. doi: 10.1111/j.1750-3841.2010.01803.x. Epub 2010 Sep 24.
Photosensitized compounds from daidzein were studied in a riboflavin model system under visible light irradiation by high-performance liquid chromatography (HPLC). As the period of light irradiation increased, concentration of daidzein decreased significantly (P < 0.05) and new peaks of daidzein derivatives were observed and changed during photosensitization. Three new peaks from photosensitized daidzein were tentatively identified as 7-, 3', 4'-trihydroxyisoflavone (or 3'-hydroxydaidzein) and 2 dimmers of daidzein by a combination of HPLC-mass spectrometry (MS) and retention times of standard compounds by HPLC. Addition of sodium azide and removal of headspace oxygen treatment affected the formation of newly formed peaks. The type I pathway of riboflavin photosensitization played more important roles than type II pathways on the formation of daidzein derivatives. Practical Application: Isoflavones are important phytochemicals found in soy foods. Generally, many foods containing soy ingredients are displayed under visible light irradiation. Also, riboflavin can be found in many foods containing vegetables. The results of this study can be used to understand the stability and changes of isoflavone aglycones in soy and soy-based foods under visible light irradiation.
在核黄素模型体系中，通过高效液相色谱法（HPLC）研究了大豆异黄酮的敏化化合物在可见光照射下的情况。随着光照时间的延长，大豆异黄酮的浓度显著降低（P<0.05），并在敏化过程中观察到和变化出新的大豆异黄酮衍生物峰。通过 HPLC-质谱（MS）联用和 HPLC 标准化合物保留时间，将敏化大豆异黄酮的三个新峰初步鉴定为 7-、3'、4'-三羟基异黄酮（或 3'-羟基大豆苷元）和大豆异黄酮的 2 个二聚体。加入叠氮化钠和去除顶空氧处理会影响新形成峰的形成。核黄素敏化的 I 型途径比 II 型途径对大豆异黄酮衍生物的形成更重要。实际应用：异黄酮是大豆食品中重要的植物化学物质。通常，许多含有大豆成分的食品在可见光下显示。此外，核黄素可以在许多含有蔬菜的食物中找到。本研究的结果可用于了解可见光照射下大豆及其豆制品中异黄酮苷元的稳定性和变化。
