Evaluation of Active Oxygen Scavenging Activity of Vegetables during Cooking

虽然已知活性氧清除活性可以预防与生活方式相关的疾病，但尚不清楚具有这种活性的食物成分在烹饪过程中如何变化以及它们在所提供的膳食中的活性如何。然而，目前还没有一种简便的方法来测定食品中的活性氧清除活性。在这项工作中，研究人员使用对1，1-二苯基-2-苦基肼基（DPPH）自由基的清除能力作为活性氧清除能力的指标。当DPPH被具有活性氧清除活性的物质捕获时，它变成非自由基形式并失去可见吸收。然而，分光光度计无法检测到食物中的这种变化，因为食物中富含色素等有色物质。因此，研究人员开发了DPPH-HPLC方法，该方法单独测定DPPH，并能够测定食品中的活性氧清除活性。在此基础上，测定了不同生长条件下甘蓝和大白菜的活性氧清除能力。有机肥和化肥处理的蔬菜体内酶活性差异不显著。最后，测定了咖喱烹调过程中活性氧清除活性的变化。蔬菜的活性随热处理而增加，而香料的活性随热处理而降低。在熟咖喱中，蔬菜的活性水平与香料相似。本研究成功地建立了食品活性氧清除能力的测定方法，并阐明了烹饪过程中活性氧清除能力的变化规律。这些结果有助于规划饮食生活，以保持健康。

Though active oxygen scavenging activity is known to prevent life-style related diseases, it is not clear how food components with this activity change during cooking and how active they are in the served meals. However, there is no convenient method to determine the active oxygen scavenging activity in food. In this work, the investigators used the scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical as the index of active oxygen scavenging activity. When DPPH is trapped by substances with active oxygen scavenging activity, it changes to non-radical form and lose visible absorption. However, spectrophotometer cannot detect this change in foods because foods are rich in colored substances such as pigments. Therefore, the investigators developed DPPH-HPLC method, which determines DPPH separately, and enabled the determination of active oxygen scavenging activity in foods. Then, the active oxygen scavenging activity of cabbage and Chinese cabbage grown in different conditions was determined. There was no significant difference between the activities of vegetables grown with chemical fertilizer and organic fertilizer. Finally, the changes of active oxygen scavenging activity during cooking of curry were determined. The activity of vegetables increased by heat, while the activity of spices decreased. In cooked curry, the level of the activity from vegetables was similar as that from spices. In conclusion, the method for the determination of active oxygen scavenging activity in foods was successfully developed, and the changes in active oxygen scavenging activity during cooking were clarified. These results contribute the planning of dietary life to keep health.