Occurrence and Exposure Assessment of Mycotoxins in Ready-to-Eat Tree Nut Products through Ultra-High Performance Liquid Chromatography Coupled with High Resolution Q-Orbitrap Mass Spectrometry

Abstract

Tree nuts have become popular snacks due to their attributed benefits in the health state. Nevertheless, their susceptibility to fungal contamination lead to the occurrence of potentially dangerous mycotoxins. Hence, the aim of this work was to evaluate the presence of mycotoxins in ready-to-eat almonds, walnuts, and pistachios from Italian markets. The most relevant mycotoxin found in almonds was α-zearalanol in 18% of samples (n = 17) ranging from 3.70 to 4.54 µg/kg. Walnut samples showed frequent contamination with alternariol, present in 53% of samples (n = 22) at levels from 0.29 to 1.65 µg/kg. Pistachios (n = 15) were the most contaminated commodity, with β-zearalenol as the most prevalent toxin present in 59% of samples ranging from 0.96 to 8.60 µg/kg. In the worst-case scenario, the exposure to zearalenone-derived forms accounted for 15.6% of the tolerable daily intake, whereas it meant 12.4% and 21.2% of the threshold of toxicological concern for alternariol and alternariol monomethyl-ether, respectively. The results highlighted the extensive presence of Alternaria toxins and zearalenone-derived forms, scarcely studied in ready-to-eat tree nut products, highlighting the necessity to include these mycotoxins in analytical methods to perform more realistic risk assessments.

Development and Validation of QuEChERS Followed by UHPLC-ToF-MS Method for Determination of Multi-Mycotoxins in Pistachio Nuts

“…For ZEA, T2 and HT2, LODs and LOQs are the same for both methods. LOQs are lower than those reported by Narváez et al [32] for AFB1, AFB2, AFG2 (0.39 µg/kg) and for AFG1, T2 and HT2 (0.78 µg/kg) using C18 for clean-up followed by UHLPC-Q-Orbitrap MS and lower than those reported by Cunha et al [19] for AFs (1.25 µg/kg) and for OTA (5 µg/kg) using C18 and Z-Sep + for clean-up followed by HPLC-Quattro Micro triple quadrupole-MS. Our results only indicate higher LOQ for T2 and HT2 than Cunha et al [19] (1.25 µg/kg). The same EMR-Lipid method with nano flow HPLC-MS allows lowest LOD, for example, 0.05 µg/kg for AFG1, AFG2 and ZEA; 0.5 µg/kg for AFB1, AFB2, FB1 and OTA and 5 µg/kg for FB2, T2 and HT2 [25].…”

“…In conclusion, for optimal results in multi-mycotoxins analysis, addition of 0.1% of FA in water was used in this study, performing the best results, because fumonisins need acidification [ 30 ] but other mycotoxins have similar peak areas with pure water or 0.1% FA. In fact, 0.1% of formic acid to extract mycotoxins from pistachio samples has previously been reported in the literature [ 25 , 31 , 32 ].…”

“…Numerous multi-mycotoxin methods for pistachio, nuts and other foodstuffs based on QuEChERS methodology have been published [ 25 , 31 , 32 , 34 , 37 , 38 , 40 , 41 , 42 ]. The main difference among those methods is the clean-up step using Immunoaffinity Chromatographic Columns (IACs) or d-SPE with different mixtures of sorbents.…”

Mycotoxins in Pistachios (Pistacia vera L.): Methods for Determination, Occurrence, Decontamination

“…In the scientific literature (Table 1), the widely used analytical column is C18 with 150 × 4.6 mm, and particle size of 5 µm. Most recent studies with UHPLC used sub-2 µm diameter particles and permitted the reduction of LC column length to 100 × 2.1 mm [60,77,86] and 50 × 2.1 mm [71,78,97]. Towards the mobile phase, the most used solvents are water, acetonitrile and methanol, with the addition of formic acid, acetic acid or ammonium formate, in different proportions and mixtures.…”

Multiclass and multi-residue screening of mycotoxins, pharmacologically active substances, and pesticides in infant milk formulas through ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry analysis

“…Among the various available method approaches used in the pretreatment of samples, the QuEChERS (quick, easy, cheap, effective, rugged, and safe) approach represents the one that comes closest to achieving the characteristics mentioned above. It is largely employed to extract different groups of compounds and represents the most frequently used pretreatment technique in foods analysis (González-Curbelo et al, 2015;Rossi et al, 2018;Samsidar et al, 2018;Narváez et al, 2020a). The most frequent analytical methods are based on liquid chromatography coupled to MS.…”