Assessment of Mycotoxins in Vitis vinifera Wines of the Southeastern United States

Abstract

Mycotoxins pose a serious worldwide threat to the safety of numerous food commodities. Red wine is prone to contamination from ochratoxin A, produced by black-spored Aspergillus spp.; it was recently discovered that some of these species can also produce the mycotoxin fumonisin B2. Although wine surveys in most world regions have determined that mean ochratoxin A levels are below the European Union’s recommended guideline maximum (2 μg/L), monitoring toxin levels in poor vintages and in emerging regions is imperative to ensure safety. The hot, humid environment of the southeastern United States proves challenging to winegrapes because of opportunistic fungal growth and high disease pressure, yet 550+ wineries exist in this expanding region. To determine the mycotoxin potential in southeastern vineyards, 30 cluster samples (representing 10 grape varieties, eight vineyards, and three states) were collected during the 2013 harvest and analyzed for ochratoxin A and fumonisins. Additionally, nearly 200 bottles of 100% southeastern U.S. red vinifera wines were tested for mycotoxins via liquid chromatography–tandem mass spectrometry (LC-MS/MS). These wines represent 18 grape varieties grown across six states during vintages between 2001 and 2013. Only four out of 157 (2.5%) wine samples tested positive for ochratoxin A, with the highest toxin quantity being at a safe level of 0.48 μg/L. Most wines (25/27, 92.6%) contained total fumonisins (B1, B2, and B3) at extremely low concentrations (<15 μg/L), far below a health-risk level. Only one grape must sample was positive for mycotoxins (20.6 μg/L fumonisin B1) out of 30 tested. Based on these results, the southeastern U.S. Vitis vinifera wine industry has a low occurrence of the mycotoxin ochratoxin A and insignificant amounts of fumonisins in red wines.