Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA; Interdepartmental Microbiology Graduate Program, Iowa State University, Ames, IA, USA.
Department of Food Science and Human Nutrition, Iowa State University, Ames, IA, USA.
Food Microbiol. 2021 May;95:103669. doi: 10.1016/j.fm.2020.103669. Epub 2020 Nov 5.
Fungal contamination is a concern for the food industry. Fungal spores resist food sterilization treatments and produce mycotoxins that are toxic for animals and humans. Technologies that deactivate spores and toxins without impacting food quality are desirable. This study demonstrates the efficiency of a high voltage atmospheric cold plasma (HVACP) technology using air to generate reactive oxygen (ROS) and nitrogen (RNS) species for the degradation of Aspergillus flavus cultures and the deoxynivalenol (DON) mycotoxin. Optical emission and absorption spectroscopy demonstrate ionization of hydroxyl groups, atomic oxygen and nitrogen, and confirm production of ROS and RNS, e.g. O, NO, NO, NO, and NO. Fungal cultures show a depletion in pigmentation and an ~50% spore inactivation after 1-min treatments. Treated spores show surface ablation and membrane degradation by scanning electron microscopy. Twenty-minute direct HVACP treatments of 100 μg of DON in one mL aqueous suspensions resulted in a greater than 99% reduction in DON structure and rescued over 80% of Caco-2 cell viability; however, the same treatment on 100 μg of powdered DON toxin only showed a 33% reduction in DON and only rescued 15% of cell viability. In summary, HVACP air treatment can inactivate both fungal spores and toxins in minutes.
真菌污染是食品工业关注的问题。真菌孢子能抵抗食品灭菌处理，并产生对动物和人类有毒的霉菌毒素。能够在不影响食品质量的情况下使孢子和毒素失活的技术是人们所期望的。本研究展示了一种使用空气产生活性氧（ROS）和活性氮（RNS）物种的高压大气压冷等离子体（HVACP）技术，用于降解黄曲霉培养物和脱氧雪腐镰刀菌烯醇（DON）霉菌毒素。光发射和吸收光谱证明了羟基、原子氧和氮的电离，并证实了 ROS 和 RNS 的产生，例如 O、NO、NO、NO 和 NO。真菌培养物显示出色素沉着减少，并且在 1 分钟的处理后孢子失活率约为 50%。扫描电子显微镜显示处理后的孢子表面烧蚀和膜降解。在 1 毫升水悬浮液中，对 100μg DON 进行 20 分钟的直接 HVACP 处理，导致 DON 结构减少 99%以上，挽救了超过 80%的 Caco-2 细胞活力；然而，对 100μg 粉末 DON 毒素进行相同的处理，DON 仅减少了 33%，仅挽救了 15%的细胞活力。总之，HVACP 空气处理可以在数分钟内使真菌孢子和毒素失活。
