Cold plasma is considered to be a novel, non-thermal, chemical-free and eco-friendly disinfection and surface modification technology. Plasma treatment of air to generate the so called plasma processed air (PPA) induces the formation of reactive oxygen (ROS) and nitrogen species (RNS). As a result, PPA has a different chemical composition compared to untreated air and suits therefore as an alternative method for microbial disinfection. However, depending on the product properties of the food matrix and its composition, a number of plasma-induced reactions also need to be taken into consideration.

This necessitates also the elucidation and understanding of the basic interactions of plasma species with bioactive compounds. The intention here is to avoid the degradation of these valuable substances and to prevent other undesirable effects in future food related applications.

In the present study, the effects of PPA treatment on selected antioxidants such as pyrocatechol and derivatives of hydroxycinnimic acid were investigated in model systems to specify possible reactions induced. Antioxidant capacity, pH value, UV–Vis spectroscopy, RP-HPLC and LC-MS analysis were applied to identify reaction products providing information on possible changes induced in food matrices by PPA treatment.

Exposure to PPA caused a perceptible color change towards yellow-brown accompanied by a strong reduction of the pH and the formation of insoluble sediments in the model solutions. The accumulation of nitrate, nitrite, but not of hydrogen peroxide was shown. LC-MS analysis demonstrated the formation of plasma-modified derivatives in all tested systems. The main reactions in liquid model solutions exposed to PPA were attributed to oxidation, nitration and polymerization of the phenolic compounds.

冷等离子体被认为是一种新颖的，非热的，无化学物质且环保的消毒和表面改性技术。对空气进行等离子体处理以生成所谓的等离子体处理后的空气（PPA）会诱导形成活性氧（ROS）和氮物质（RNS）。结果，PPA与未经处理的空气相比具有不同的化学组成，因此适合作为微生物消毒的替代方法。然而，取决于食物基质的产品特性及其组成，还需要考虑许多等离子体诱导的反应。

这也需要阐明和理解血浆物质与生物活性化合物的基本相互作用。此处的目的是避免这些有价值的物质降解，并防止在未来与食品相关的应用中产生其他不良影响。

在本研究中，在模型系统中研究了PPA处理对选定的抗氧化剂（如邻苯二酚和羟基肉桂酸衍生物）的影响，以明确可能引起的反应。抗氧化能力，pH值，UV-Vis光谱，RP-HPLC和LC-MS分析用于鉴定反应产物，从而提供有关PPA处理在食品基质中可能引起的变化的信息。

暴露于PPA会引起明显的黄褐色颜色变化，伴随着pH值的强烈降低和模型溶液中不溶性沉积物的形成。显示了硝酸盐，亚硝酸盐而不是过氧化氢的积累。LC-MS分析表明，在所有测试的系统中均形成了血浆修饰的衍生物。暴露于PPA的液体模型溶液中的主要反应归因于酚类化合物的氧化，硝化和聚合。