Levels of Alternaria Toxins in Selected Food Commodities Including Green Coffee

Abstract

Alternaria toxins are emerging mycotoxins, candidates for regulation by European Authorities. Therefore, highly sensitive, confirmatory, and reliable analytical methodologies are required for their monitoring in food. In that context, an isotope dilution LC-MS/MS method was developed for the analysis of five Alternaria toxins (Altenuene, Alternariol, Alternariol monomethylether, Tentoxin, and Tenuazonic Acid) in a broad range of commodities including cereals and cereal-based products, tomato-based products, tree nuts, vegetable oils, dried fruits, cocoa, green coffee, spices, herbs, and tea. Validation data collected in two different laboratories demonstrated the robustness of the method. Underestimation of Tenuazonic Acid level in dry samples such as cereals was reported when inappropriate extraction solvent mixtures were used as currently done in several published methodologies. An investigation survey performed on 216 food items evidenced large variations of Alternaria toxins levels, in line with data reported in the last EFSA safety assessment. The analysis of 78 green coffee samples collected from 21 producing countries demonstrated that coffee is a negligible source of exposure to Alternaria toxins. Its wide scope of application, adequate sample throughput, and high sensitivity make this method fit for purpose for the regular monitoring of Alternaria toxins in foods.

A Dilute and Shoot Strategy for Determining Alternaria Toxins in Tomato-Based Samples and in Different Flours Using LC-IDMS Separation

“…This suggests that the sample dilution already reduced the ME. Generally, AOH, AME, and TEA have high MEs [ 13 , 18 , 20 , 24 , 25 , 30 , 31 , 32 , 33 , 36 ]. However, only the signal of AOH was considerably influenced by MEs in all matrices analyzed using the described method.…”

“…The recent literature on Alternaria toxins has shown that the most suitable technique to analyze Alternaria toxins in food is liquid chromatography–tandem mass spectrometry (LC-MS/MS) [ 6 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 ]. The research articles and inhouse validation of the candidate standard method focused on the significant matrix effect (ME) [ 13 , 14 ], which greatly influences the LC-MS/MS analysis of Alternaria toxins in food matrices [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Consequently, isotope dilution mass spectrometry (...…”

“…The research articles and inhouse validation of the candidate standard method focused on the significant matrix effect (ME) [ 13 , 14 ], which greatly influences the LC-MS/MS analysis of Alternaria toxins in food matrices [ 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Consequently, isotope dilution mass spectrometry (IDMS) must be employed in order to compensate for ion suppression, which is caused by co-eluting matrix constituents [ 13 , 18 , 20 , 24 , 25 , 27 , 30 , 31 , 35 , 36 ]. When the first trial was carried out for Alternaria toxins by the JRC, the stable isotopically labeled internal standards (ISTD) were not available in the market, and an approach of matrix-matched calibration was suggested [ 10 ].…”

“…Currently, ISTDs are commercially available and the LC-IDMS method can now be carried out for to analyze Alternaria toxins. Further, the apparent compensation of the ME can also be done [ 13 , 18 , 21 , 24 , 25 , 27 , 30 , 31 , 35 ]. It is important to emphasize that all corresponding ISTD should be used because the different Alternaria toxins undergo various ME’s due to the different chemical structures and retention times in HPLC separation [ 13 , 18 , 21 , 24 , 25 , 27 , 30 , 31 , 35 ].…”

“…Another aim of SPE is to avoid sample dilution during sample preparation; therefore, the low concentration levels (down to 1 µg/kg) can be accurately measured using LC-MS/MS instruments with enhanced sensitivity. Some studies recently suggested the quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation to analyze Alternaria toxins in various food samples [ 22 , 23 , 24 , 30 ]. This extraction method is generally used to analyze pesticides, so the raw food extract, prepared for toxins, can also be analyzed for pesticides.…”