Determination of mycotoxin profiles characteristic of Alternaria strains isolated from Malbec grapes

Abstract

The world grape production has increased, reaching 751million quintals (Mql) in 2013. Many Alternaria species have beenstudied for their ability to produce secondary metabolites in foods, some ofwhich have toxic properties with tenuazonic acid (TA), alternariol (AOH),alternariol methyl ether (AME) being the most important ones. The aim was todetermine the characteristic mycotoxin production profiles of Alternaria strainsisolated from Malbec grapes in the Patagonian región of Argentina. Fifty Alternariaisolates (5 A. alternata, 5 A. arborescens and 40 A.tenuissima) were analyzed for the production of mycotoxins (TA, AOH andAME) in autoclaved rice media by High Performance Liquid Chromatography (HPLC).All isolates were found to be producers of mycotoxins; the 100% was producer ofTA (0.016?21.031 mg/kg), 98% produced AOH (0.003?0.057 mg/kg) and 36% produced AME (0.001?0.133mg/kg). Thirty-three isolates co-produced the three mycotoxins. In this study,it was demonstrated a high toxigenic potential of Alternaria isolates.Although Alternaria growth on grapes has been amply demonstrated, thereare few studies about the incidence their more characteristic mycotoxin sandtheir toxicogenic capacity determination in grapes, wines and derivatives. Inaddition, mycotoxins studied in this work are not regulated in oenology. Therefore,further studies should be conducted to assess the health risk due to thepresence of Alternaria toxins in grapes, wine, grape juice and raisins.