Abstract：
Reactive carbonyl species (RCS) are generated during thermal food processing, and their accumulation in the body increases the risk of various chronic diseases. Herein, the RCS-scavenging ability of theanine, a unique nonproteinogenic amino acid, was evaluated in terms of the scavenging rate, reaction kinetics, and reaction pathway using LC-MS/MS. Three major products of theanine conjugated with acrolein (ACR) and glyoxal (GO) were prepared and identified using nuclear magnetic resonance. Thereafter, the simultaneous reactions of four types of RCS (namely, ACR, crotonaldehyde, methylglyoxal, and GO) with theanine were discussed in RCS-theanine and RCS-tea models. Under different reaction ratios, theanine could nonspecifically scavenge the four coexisting RCS by forming adducts with them. The amount of theanine-RCS adducts in green and black tea was more than that of catechin (epigallocatechin gallate, epigallocatechin, epicatechin gallate, and epicatechin)-RCS adducts despite the lower content of theanine than catechins. Thus, theanine, as a food additive and dietary supplement, could demonstrate new bioactivity as a promising RCS scavenger in food processing.
摘要：
反应性羰基（RCS）是在热食品加工过程中产生的，它们在体内的积累增加了各种慢性疾病的风险。在这里，茶氨酸清除RCS的能力，一种独特的非蛋白质氨基酸，根据清除速率进行评估，反应动力学，和使用LC-MS/MS的反应途径。制备了与丙烯醛（ACR）和乙二醛（GO）缀合的茶氨酸的三种主要产物，并使用核磁共振进行了鉴定。此后,四种类型的RCS的同时反应(即，ACR,巴豆醛,甲基乙二醛，和GO）在RCS-茶氨酸和RCS-茶模型中讨论了茶氨酸。在不同的反应比例下，茶氨酸可以通过与它们形成加合物来非特异性地清除四个共存的RCS。绿茶和红茶中茶氨酸-RCS加合物的含量高于儿茶素（表没食子儿茶素没食子酸酯，表没食子儿茶素，表儿茶素没食子酸酯,和表儿茶素）-RCS加合物，尽管茶氨酸的含量低于儿茶素。因此，茶氨酸,作为食品添加剂和膳食补充剂，作为食品加工中一种有前途的RCS清除剂，可以证明新的生物活性。
