Department of Food Science and Human Nutrition, Iowa State University , Ames, Iowa 50011-1061, United States.
J Agric Food Chem. 2017 Aug 2;65(30):6222-6230. doi: 10.1021/acs.jafc.7b01604. Epub 2017 Jul 18.
High-voltage atmospheric cold plasma (HVACP) is a novel nonthermal decontamination technology that has potential for use in the food industry. In this study, HVACP was applied to treat pure aflatoxin B (AFB) powder on a glass slide. AFB was degraded by 76% using a 5 min HVACP treatment in air having 40% relative humidity. The degradation products of AFB were separated, and their molecular formulas were elucidated using liquid-chromatography time-of-flight mass spectrometry (HPLC-TOF-MS). Six main degradation products were observed. The structures of the degradation products were further clarified via orbitrap mass spectrometry by means of fragmentation of the parental ions. Two degradation pathways were proposed on the basis of the structure of the degradation products. Among the six degradation products, two were ozonolysis products of AFB. The appearance of the other four degradation products indicates that AFB was degraded by other reactive species besides ozone that were generated during HVACP treatment. Reactive oxygen gas species are suggested as the major agents for aflatoxin degradation during HVACP treatment. Two degradation pathways of AFB by HVACP treatment were proposed. One pathway involves reactions in which H, OH, CHO radicals are added. The other involves epoxidation by HO radicals and oxidation of AFBby the combined effects of the oxidative species OH, HO, and O. According to the structure-bioactivity relationship of AFB, the bioactivity of the AFB samples subjected to HVACP treatment is significantly reduced because of the disappearance of the C8═C9 double bond in the furofuran ring in all of the major degradation products as well as the modification of the lactone ring, cyclopentanone, and the methoxyl group.
高压大气压冷等离子体（HVACP）是一种新型的非热消毒技术，有望在食品工业中得到应用。本研究将 HVACP 应用于载玻片上的纯黄曲霉毒素 B（AFB）粉末。在相对湿度为 40%的空气中，使用 5 分钟的 HVACP 处理可使 AFB 降解 76%。用液相色谱-飞行时间质谱法（HPLC-TOF-MS）分离 AFB 的降解产物，并阐明其分子式。观察到六个主要的降解产物。通过母体离子的碎片化，利用轨道阱质谱进一步阐明了降解产物的结构。基于降解产物的结构，提出了两种降解途径。在六种降解产物中，有两种是 AFB 的臭氧分解产物。其他四种降解产物的出现表明，在 HVACP 处理过程中，除了臭氧之外，还有其他活性物质参与了 AFB 的降解。活性含氧气体被认为是 HVACP 处理过程中降解黄曲霉毒素的主要试剂。提出了 HVACP 处理 AFB 的两种降解途径。一种途径涉及 H、OH、CHO 自由基的加成反应。另一种途径涉及 HO 自由基的环氧化和 OH、HO 和 O 等氧化物种的联合氧化作用。根据 AFB 的结构-生物活性关系，由于所有主要降解产物中环戊烷酮、内酯环、呋喃环中 C8═C9 双键以及内酯环、环戊酮和甲氧基的修饰的消失，经 HVACP 处理的 AFB 样品的生物活性显著降低。
