Cold Plasma Treatment as an Alternative for Ochratoxin A Detoxification and Inhibition of Mycotoxigenic Fungi in Roasted Coffee

Abstract

Ochratoxin A (OTA) produced by mycotoxigenic fungi (Aspergillus and Penicillium spp.) is an extremely toxic and carcinogenic metabolite. The use of cold plasma to inhibit toxin-producing microorganisms in coffee could be an important alternative to avoid proliferation of mycotoxigenic fungi. Roasted coffee samples were artificially inoculated with A. westerdijikiae, A. steynii, A. versicolor, and A. niger, and incubated at 27 °C over 21 days for OTA production. Samples were cold plasma treated at 30 W input power and 850 V output voltage with helium at 1.5 L/min flow. OTA production in coffee was analyzed by high performance liquid chromatography coupled to a mass spectrometer (HPLC-MS). After 6 min of treatment with cold plasma, fungi were completely inhibited (4 log reduction). Cold plasma reduces 50% of OTA content after 30 min of treatment. Toxicity was estimated for extracts of artificially contaminated roasted coffee samples using the brine shrimp (Artemia salina) lethality assay. Toxicity for untreated roasted coffee was shown to be “toxic”, while toxicity for cold plasma treated coffee was reduced to “slightly toxic”. These results suggested that cold plasma may be considered as an alternative method for the degradation and reduction of toxin production by mycotoxigenic fungi in the processing of foods and feedstuffs.

Application of Novel Non-Thermal Physical Technologies to Degrade Mycotoxins

“…As for the last-mentioned item, NTP has big potential to reduce the volume of mycotoxins by both fungi reduction and mycotoxins degradation with high potential for practical applications during the whole food production chain. The most recent studies [ 48 , 49 , 50 , 51 ] suggest practical applications of NTP to degrade mycotoxins on roasted coffee, hazelnuts, maize, and rice. The list of these studies can be found in Table 1 .…”

Plasma Technology Increases the Efficacy of Prothioconazole against Fusarium graminearum and Fusarium proliferatum Contamination of Maize (Zea mays) Seedlings

“…Cold plasma technologies are being widely tested on seeds to enhance the germination rate and plant growth [23][24][25][26][27]. They have been also applied for inactivating pathogenic and spoilage microorganisms in food [28][29][30]. All proposed applications of cold plasma technology for agriculture, including water treatments, are presented in Puac et al [31].…”

Cold Plasma: Clean Technology to Destroy Pathogenic Micro-organisms

“…Recent developments in sterilization technologies in the last decade focuses on the following factors: low temperature operation so that the technology is suitable for a variety of materials, shorter cycles of operation for faster sterilization, environmental friendliness, and cost reduction (Bunz et al 2018). Cold plasma can be a useful tool for destroying all types of pathogenic micro-organisms (Bunz et al 2018;Nasir et al 2016;Casas-Junco et al 2019). Cold plasma can be used in vacuum as well as in atmospheric pressure (Barve et al 2017;Kar et al 2018;Sharma et al 2017Sharma et al , 2018.…”