Long-term prevention of oxidation of bioactive material using three-dimensional regeneration reaction of antioxidant with catechin

本研究通过将两亲性儿茶素与亲脂性维生素E和亲水性维生素C结合，设计了一种抗氧化剂的高速再生循环，目的是长期防止食物系统中f3-胡萝卜素氧化。在维生素E和C存在的情况下，阐明了以下几点：1)只要系统中存在维生素E，就可以防止胡萝卜素氧化；2)维生素C与消耗和再生维生素E两种对比反应有关；3)在特定条件下，胡萝卜素氧化的预防期显著延长。传统上认为维生素C对维生素E的再生反应有助于延长预防期。然而，系统中的氧气被澄清几乎被维生素C本身的氧化所消耗，因此胡萝卜素的氧化被阻止了。新的动力学模型考虑了胡萝卜素、维生素E和C的反应机理，较好地描述了系统中维生素C和氧含量对促进或阻止胡萝卜素氧化的对比效应。另一方面，在儿茶素存在的情况下，阐明了以下几个问题：1)儿茶素与消耗胡萝卜素和防止胡萝卜素氧化两种对比反应有关；2)儿茶素的结构控制了哪一种反应优先发生。

In this research, a high-speed regeneration cycle of antioxidants was designed by combining an amphiphilic catechin with a lipophilic vitamin E and a hydrophilic vitamin C for the purpose of long-term prevention of f3-carotene oxidation in the food system. In the presence of vitamin E and C, the following things were clarified: 1) the carotene oxidation was prevented as long as vitamin E existed in the system, 2) vitamin C was related to two contrastive reactions consuming and regenerating vitamin E, 3) the prevention period of carotene oxidation significantly increased under specific conditions. Conventionally the regeneration reaction of vitamin E by vitamin C was considered to contribute the increase of the prevention period. However, oxygen in the system was clarified to be almost consumed by the oxidation of vitamin C itself and consequently the carotene oxidation was prevented. The novel kinetic model considering the reaction mechanisms of carotene, vitamin E and C well described the contrastive effects progressing or preventing the carotene oxidation according to the amounts of vitamin C and oxygen in the system. On the other hand, the following things were clarified in the presence of catechin: 1) catechin was related to two contrastive reactions consuming carotene and preventing the carotene oxidation and 2) the structure of catechin was controlled which reaction preferentially occurred.