Foti Mario C, Ingold K U
Istituto di Chimica Biomolecolare del CNR-Sezione di Catania, Via del Santuario 110, I-95028 Valverde (CT), Italy.
J Agric Food Chem. 2003 Apr 23;51(9):2758-65. doi: 10.1021/jf020993f.
gamma-Terpinene (TH), a monoterpene hydrocarbon present in essential oils, retards the peroxidation of linoleic acid (LH). The peroxidation of TH has been shown to yield p-cymene as the only organic product in a chain reaction in which the chain carrier is the hydroperoxyl radical, HOO(.). The peroxidation of LH is well-known to be a chain reaction in which the chains are carried by linoleylperoxyl radicals, LOO., and the products are linoleyl hydroperoxides. The retardation of LH peroxidation by TH has been found to be due to rapid chain termination via a very fast cross-reaction between HOO. and LOO. radicals. This antioxidant mechanism is completely different from the mechanism of antioxidant action of vitamin E. Since vitamin E becomes a prooxidant at high concentrations, the addition of essential oils containing TH to edible lipids may provide an alternative or supplementary strategy for obtaining large increases in their oxidative stability and shelf life, something that cannot be achieved by simply adding more and more vitamin E.
γ-松油烯（TH）是一种存在于香精油中的单萜烃，它能延缓亚油酸（LH）的过氧化反应。TH的过氧化反应已被证明在链式反应中仅生成对异丙基甲苯作为有机产物，其中链式载体是氢过氧自由基HOO(·)。众所周知，LH的过氧化反应是一个链式反应，其中链由亚油酰过氧自由基LOO·携带，产物是亚油酰氢过氧化物。已发现TH对LH过氧化反应的延缓作用是由于HOO·和LOO·自由基之间非常快速的交叉反应导致链式反应迅速终止。这种抗氧化机制与维生素E的抗氧化作用机制完全不同。由于高浓度时维生素E会成为促氧化剂，因此在食用脂质中添加含有TH的香精油可能为大幅提高其氧化稳定性和保质期提供一种替代或补充策略，而这是仅通过添加越来越多的维生素E无法实现的。
