Mycotoxins detoxification using UV irradiation and advanced oxidation processes

Ultraviolet (UV-C) irradiation is a method of disinfection that is effective against many microorganisms and is also applied for chemical contaminant treatment via direct photolysis and advanced oxidation with sensitizers such as hydrogen peroxide. The present study evaluates whether UV-C can be an effective method to destroy patulin in apple juice. UV-C irradiation experiments were conducted using a collimated beam system operating at 253.7 nm. It was observed that patulin was not destroyed in pure water, but was degraded in pure and diluted apple juice upon UV-C irradiation, suggesting that chromophores (such as riboflavin) in the juice were important factors in the photo degradation. From an initial patulin concentration of approximately 200 ppb, UV-C dose of 400 mJ. cm -2 successfully reduced patulin concentration by 69.47 (±0.69) % (p\u3c0.05). In cell culture studies, Cell viability percentage increased from 47.3% to 81.64% as UV-C dose increased from 0 to 400 mJ. cm-2 . This study clearly shows the potential for using UV-C treatment for patulin degradation in turbid liquid foods such as apple juice. This study also deals with mitigation of aflatoxins (AFB1, AFB2, AFG1, AFG2) in pure water with and without the use of hydrogen peroxide as photosensitizer. UV irradiation experiments were conducted using a collimated beam system operating from 200 to 300 nm. Known concentrations of aflatoxins with and without hydrogen peroxide (0.15%) spiked in water and irradiated at UV doses ranging from 0-4.88 J.cm-2. It was observed that maximum UV irradiation exposure reduced AFB1, AFB2 and AFG1 levels in water by 98.25, 29.77 and 67.21% respectively. A dose of 4.88 J.cm-2 reduced the AFG2, AFG1, AFB2 and AFB1 content by 91.65, 75.57, 99.94 and 96.48%, respectively in water spiked with 0.15% hydrogen peroxide (p\u3c0.05). We hypothesize formation of singlet and triplet reactive oxygen species initiated by UV light, may have caused a photolytic damage to the AFB1, AFB2, AFG1 and AFG2. This study clearly shows the potential for using advanced oxidation processes (AOP) for degrading aflatoxins. This work provides the first demonstration of a non-thermal technology allowing mycotoxin destruction at a commercially relevant UV doses