2.2.2. Cold Plasma

The common states of matter are solid, liquid, and gas; plasma, the fourth, uncommon state, is formed by supplying enough energy to substances to assure the transition from the solid to the ionized state [96].

Cold atmospheric plasma (CAP) is a non-thermal technology that has shown its efficiency in reducing fungal pathogens and their toxins [64]. This technology is a successful alternative to the traditional treatments (heat treatment, wet chemistry, or UV-irradiation) usually implemented. These treatments proved their inefficiency in mitigating AF without affecting the food and feed quality [77].

Complete degradation of aflatoxin B1 is achieved by the effect of CAP-RONS (Reactive Oxygen Plasma and Nitrogen Species), which have a high oxidative potential and high affinity to react with the vinyl bonds in organic molecules. These RONS are yielded by the generation of non-equilibrium atmospheric in ambient air. The same degradation rate is achieved by applying the same CAP system to contaminated corn kernels. CAP treatment is faster than UV-C treatment and is significantly more efficient in AFB1 reduction than UV-C treatment [77].

A different study explored the effect of low-pressure dielectric barrier discharge (DBD) plasma on the degradation of T-2 and HT-2 toxins in oat flour by using different working gases. Only partial degradation of T-2 and HT-2 toxins was achieved by applying this technology, and all the experiments yielded similar results to those obtained by the thermal treatments usually applied during food processing, such as cooking, extrusion, or roasting. None of the used gases in this study could completely detoxify the oat flour samples. The highest degradation rate of T-2 and HT-2 toxins reached 43.25% and 29.23%, respectively, after treating the samples with nitrogen for 30 min. CAP treatments using molecular oxygen and air as working gases did not affect these toxins [78].

Another study confirmed the results of the previous one that DBD plasma is not capable of achieving complete detoxification of AFB1 and FB1 in food matrices. In this study, spiked maize kernels were exposed to a pulsed dielectric barrier discharge (DBD) plasma jet for 10 min. The detoxification rate was 65% for maize grains spiked with AFB1 with an initial concentration of 1.25 ng/g and 64% for maize grains spiked with FB1 with an initial concentration of 259 ng/g [79].

Roasted coffee beans artificially contaminated with ochratoxin A (OTA) were treated with cold plasma for 30 min, and the degradation rate reached 50%. This result was satisfactory as per the EU standards. The brine shrimp lethality assay was used to evaluate toxicity, and the result was "Toxic" for the untreated beans and "Slightly Toxic" for the treated ones [80].

CAP has a low detrimental effect on the organoleptic and nutritional quality of foods and feeds. This treatment could explain this treatment's low penetration depth, so the degradation may affect only the superficial layers and protect all internal components. The generated RONS may affect the antioxidants and lipids present in the product [79]. SBD plasma has been shown to be more efficient than DBD plasma in the reduction of aflatoxins and other mycotoxins (Table 2), which seems to be more practical and scalable at the agri-food industrial level [77].

#### 2.2.3. Pulsed Light

Pulsed light is a non-thermal treatment used to improve food safety and maintain the quality of food products by preventing the effect of heat treatment adopted in other techniques. It is generated by the flash repetition of non-coherent, broad-spectrum, highintensity light [97]. It includes infrared, ultraviolet, and visible rays. It has been FDA approved since 1996 to be used for the superficial decontamination of food products (maximum fluence 12 J cm<sup>−</sup>2) [62,98].

This technology achieved higher reduction rates of AFB1 and AFB2 in rice bran than in rough rice because of its high efficiency on the surface and external parts [83]. Another study showed a positive relationship between the aflatoxins degradation rate and the initial concentrations in solid medium and the intensity of pulsed light treatment [82].

The effect of pulsed light on red pepper powder to mitigate microorganisms and mycotoxins such as total AF, AFB1, and OTA was investigated. The application of 61 pulses at high fluence (9.1 J/cm2) for 20 s effectively reduced the yeast and molds and the total plate count in red pepper powder. The same treatment parameters were applied to cause the reduction of total aflatoxins by 50.9%, aflatoxin B1 by 67.2%, and ochratoxin A by 36.9%. Total phenols increased apparently and significantly, while the total color was slightly changed [81].
