The effect of cold atmospheric pressure plasma on Aspergillus ochraceus and ochratoxin A production

Comprehensive Insights into Ochratoxin A: Occurrence, Analysis, and Control Strategies

Ochratoxin A (OTA) is a toxic mycotoxin produced by some mold species from genera Penicillium and Aspergillus. OTA has been detected in cereals, cereal-derived products, dried fruits, wine, grape juice, beer, tea, coffee, cocoa, nuts, spices, licorice, processed meat, cheese, and other foods. OTA can induce a wide range of health effects attributable to its toxicological properties, including teratogenicity, immunotoxicity, carcinogenicity, genotoxicity, neurotoxicity, and hepatotoxicity. OTA is not only toxic to humans but also harmful to livestock like cows, goats, and poultry. This is why the European Union and various countries regulate the maximum permitted levels of OTA in foods. This review intends to summarize all the main aspects concerning OTA, starting from the chemical structure and fungi that produce it, its presence in food, its toxicity, and methods of analysis, as well as control strategies, including both fungal development and methods of inactivation of the molecule. Finally, the review provides some ideas for future approaches aimed at reducing the OTA levels in foods.

Nonthermal Plasma Effects on Fungi: Applications, Fungal Responses, and Future Perspectives

The kingdom of Fungi is rich in species that live in various environments and exhibit different lifestyles. Many are beneficial and indispensable for the environment and industries, but some can threaten plants, animals, and humans as pathogens. Various strategies have been applied to eliminate fungal pathogens by relying on chemical and nonchemical antifungal agents and tools. Nonthermal plasma (NTP) is a potential tool to inactivate pathogenic and food-contaminating fungi and genetically improve fungal strains used in industry as enzyme and metabolite producers. The NTP mode of action is due to many highly reactive species and their interactions with biological molecules. The interaction of the NTP with living cells is believed to be synergistic yet not well understood. This review aims to summarize the current NTP designs, applications, and challenges that involve fungi, as well as provide brief descriptions of underlying mechanisms employed by fungi in interactions with the NTP components.

Non-thermal plasma induces changes in aflatoxin production, devitalization, and surface chemistry of Aspergillus parasiticus

Non-thermal plasma (NTP) represents the fourth state of matter composed of neutral molecules, atoms, ions, radicals, and electrons. It has been used by various industries for several decades, but only recently NTPs have emerged in fields such as medicine, agriculture, and the food industry. In this work, we studied the effect of NTP exposure on aflatoxin production, conidial germination and mycelial vitality, morphological and surface changes of conidia and mycelium. When compared with colonies grown from untreated conidia, the colonies from NTP-treated conidia produced significantly higher levels of aflatoxins much earlier during development than colonies from untreated conidia. However, at the end of cultivation, both types of cultures yielded similar aflatoxin concentrations. The increase in the accumulation of aflatoxins was supported by high transcription levels of aflatoxin biosynthetic genes, which indicated a possibility that NTP treatment of conidia was having a longer-lasting effect on colony development and aflatoxins accumulation. NTP generated in the air at atmospheric pressure effectively devitalized Aspergillus parasiticus in conidia and hyphae within a few minutes of treatment. To describe devitalization kinetics, we applied Weibull and Hill models on sets of data collected at different exposure times during NTP treatment. The damage caused by NTP to hyphal cell wall structures was displayed by raptures visualized by scanning electron microscopy. Fourier transform infrared spectroscopy demonstrated that changes in cell envelope correlated with shifts in characteristic chemical bonds indicating dehydration, oxidation of lipids, proteins, and polysaccharides. Key points • Non-thermal plasma increases aflatoxin production shortly after treatment. • Non-thermal plasma rapidly devitalizes Aspergillus parasiticus. • Non-thermal plasma disrupts the cell surface and oxidizes biological components.

Bio-control on the contamination of Ochratoxin A in food: Current research and future prospects

Ochratoxin A (OTA) is a secondary metabolite of several fungi and widely exists in various species of foods. The establishment of effective methods for OTA reduction is a key measure to ensure food processing and human health. This article reviews the current research of OTA reduction by biological approaches, summarizes the characteristics and efficiency of them, and evaluates the transformation pathways and metabolites safety of each degradation technology. The shortcomings of various methods are pointed out and future prospects are also proposed. Biological methods are the most promising approaches for OTA control. The defect of them is the long processing time and the growth of microbial cells may affect the product quality. Therefore, the control of OTA contamination should be conducted according to the food processing and their product types. Besides, it is significant for the exploitation of new strains, enzyme and novel adsorbents.

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The application of physical and chemical methods has been restricted.

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Existing biological methods can effectively detoxify OTA.

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OTA reduction systems should be established for different food.

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The exploitation of novel equipment, enzyme and adsorbents is essential.