Common buckwheat (Fagopyrum esculentum) is economically important crop used in the food industry worldwide, with a net global production of almost 4 million tons. Cold plasma (ionized gas at room temperature) treatment of materials is widely used for both activation and decontamination of surfaces. Cold plasmas have lower temperatures compared to high-temperature plasmas, which gives them the potential to be used on biological, heat-sensitive materials. In recent years, these methods have been successfully used in agriculture and biomedicine to improve the quality of seed germination and the inactivation of pathogenic microorganisms colonizing plant seeds. New approaches to the use of cold plasma could thus ensure a more profitable and sustainable production and processing of common buckwheat. In our study we investigated the effect of cold plasma on germination and fungal communities of buckwheat seeds. The plasma was generated by an inductively coupled (IC) radio frequency (RF) power supply with a frequency of 27.12 MHz. The gas used was oxygen (O2), at a pressure of 50 Pa and an operating power of about 8 kW. These parameters remained the same at all treatments, only the plasma exposure time was changed (0, 15, 30, 45, 60, 90 and 120 seconds). In contrast to the results of other authors, we found that treatment with cold plasma had no positive effect on the germination of the seeds used, and we observed almost no germination at exposures of 90 s and 120 s. We successfully isolated and identified 32 species of fungi that were grown on PDA media. The most abundant species were: Epicoccum nigrum, Didymella glomerata, Alternaria alternaria and Hannaella sp. We found that 120 s treatment with cold plasma successfully decontaminated most of the fungi from the seed surface and was comparable with a classical sterilized control (30 % H2O2). Nevertheless, some fungal species (Hannaella sp.) remained present even after the longest plasma exposure. Based on our findings, seed cold plasma treatments with exposures of 120 s and above, could become important as a decontamination agent for the purposes of the food industry or to prevent fungal growth on buckwheat grains in warehouses and silos for further processing.
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