Development Of Multi-component Quantitation Methodology And Degradation Means Via Electrolyzed Water Of Mycotoxin Contamination In Fresh Fish And Dried Seafoods

Mycotoxins are secondary metabolites produced by fungi,and the most relevant groups of mycotoxins are aflatoxins, ochratoxin A, trichothecenes(type A: HT-2 and T-2 toxin, and type B: deoxynivalenol), zearalenone, fumonisins B1 and B2, et al. They are nephrotoxic natural compounds which can lead to human mutagenesis, teratogenesis and carcinogenesis. They could be detected in several kinds of food, i.e., cereals and their derivatives, meat, and spices. Moreover, trace levels of mycotoxins have been detected in muscle and ovary of fresh fish as well as dried fish products in earlier studies, which may bring potential risk to consumers’ health. Therefore, it is urgent to develop methods for simultaneous determination and degradation of multi-mycotoxins in aquatic derived foods. In the present study, a reliable liquid chromatography–tandem mass spectrometry(LC–MS/MS) method was developed for simultaneous determination of mycotoxins in aquatic derived foods, electrolyzed oxidizing water was used to eliminate mycotoxins in standard solutions and in semi-dry fish products, and the degradation products were also investigated.1. A reliable liquid chromatography–tandem mass spectrometry(LC–MS/MS)method was developed for simultaneous determination of nine mycotoxins, i.e.,aflatoxin B1(AFB1), aflatoxin B2(AFB2), aflatoxin G1(AFG1), aflatoxin G2(AFG2),ochratoxin A(OTA), zearalenone(ZEN), T-2 toxin, HT2 toxin and deoxynivalenol(DON), in aquatic derived foods(muscle and entrails of fish as well as dried aquatic products). With regards to the high complexity of the matrices, extraction solvent, time,and temperature as well as clean-up cartridges were optimized to improve extraction efficiency and reduce matrix effects. The optimum procedure included ultrasound-assisted extraction with acetonitrile/water/acetic acid(79/20/1, v/v/v) atII40 °C for 30 min, defatting with n-hexane and purification by Oasis HLB cartridges.The method was further validated by determining the linearity(R2 ≥ 0.9989), sensitivity(limit of detection ≤ 2 μg/kg, limit of quantitation ≤ 3 μg/kg), recovery(72.2-119.9%)and precision(≤ 18.3%) in muscle and entrails of fresh crucian carp(Carassius carassius) as well as dried fish products. The method was proven to be suitable for its intended purposes. Mycotoxins of OTA, ZEN and AFB2 have been found in aquatic derived foods for the first time.2. In the present study, the effects of acidic electrolyzed oxidizing water(Ac EW)and alkaline electrolyzed water(Al EW) on the elimination of AFB1, AFB2, AFG1,AFG2 and OTA in standard solutions were explored. The degradation products of these five mycotoxins treated by Al EW were also investigated. The results showed that more than 90% of these five mycotoxins in stardard solutions were degraded after Al EW treatment, however, the Ac EW had lower degradation efficiency on OTA. These mycotoxins were degraded into three new products by Al EW. Therefore, Al EW could be used to effective degrade mycotoxins and provide reference for futher degradation study.3. The elimination effects of AFB1, AFB2, AFG1, AFG2 and OTA in semi-dry fish products by acidic electrolyzed water(Ac EW-1, Ac EW-2 and Ac EW-3) and alkaline electrolyzed water(Al EW-1, Al EW-2 and Al EW-3), which prepared from different content ration of sodium chloride solutions(1.5, 2.0, 2.5 g/L), respectively, were investigated. Furthermore, four combination treatments(Ac EW followed by Al EW,Al EW followed by Ac EW, Al EW followed by tap water(TW) and Ac EW followed by TW), and three single treatments(Ac EW, Al EW and TW) were also investigated.Meanwhile, some external factors(volume of electrolyzed water, soak temperature and time) were also studied, which might influence the elimination rates of mycotoxins in semi-dry fish products. The results indicated that the removing rates of these five mycotoxins in semi-dry fish products after Ac EW-3 treatment were better than Ac EW-1and Ac EW-2 treatments. The elimination effects of these five mycotoxins in semi-dry fish products among Al EW-1, Al EW-2, and Al EW-3 treatments have no significant differences(p > 0.05). The removing rates of combination treatments were better than that of single treatments. The best effect on mycotoxins elimination for contaminated semi-dry fish product(2.0 ± 0.1 g, 40 μg/kg) was obtained after the treatment of oscillation with 10 m L Al EW at 80 rpm for 40 min(35 °C) followed by soaking with 10 m L TW for 20 min(25 °C), which the elimination rates for AFB1, AFB2, AFG1, AFG2 and OTA were 81.16%, 75.01%, 77.19%, 75.60% and 43.62%, respectively. Therefore,Al EW could be used to soak the semi-dry fish products as a result of removing the redundant salts and effective degrading mycotoxins before cooking, so as to protect the health of the consumers.