Multi-Mycotoxin Quantification in Soy Protein Powders, Soymilk, Soybeans (Glycine max) and Other Legumes Using a New Targeted Differential Ion Mobility LCMS Method.

Foods contaminated with fungal mycotoxins pose a serious risk to human health. Soy and other legumes are a vital source of alternative protein, yet the rates of mycotoxin contamination are not understood. We therefore developed a sensitive stable-isotope-dilution-differential-ion-mobility-spectrometry-LC-MS method for the quantification of 43 mycotoxins in soylike matrixes. Extraction by QuEChERS-d-SPE-PSA reduced matrix effects, while Differential-Ion-Mobility-Spectrometry (DMS) decreased background-noise and enabled the selective quantification of acetyl-deoxynivalenol (ACDON) isomers. Careful parameter selection was required since 3-ACDON produced tautomeric ion-mobility peaks. Mycotoxins were rarely found in whole soybeans, with only 3 out of 13 samples containing tentoxin, tenuazonic acid, or altenuene. However, mycotoxins were found in 52% non-soy legumes, 58% soy-protein powders, and 100% soy-milk samples including infant formulas. Alternaria mycotoxins were the most prevalent mycotoxins with Fusarium and Aspergillus mycotoxins also observed. Thus, although soybeans appear relatively resistant to mycotoxin contamination, even compared to other legumes, contamination may be introduced during storage and processing.