Low Occurrence of Patulin-Producing Strains of <i>Penicillium</i> in Grapes and Patulin Degradation during Winemaking in Chile

Abstract

<i>Penicillium expansum</i> has emerged as the cause of storage decay of table grapes (<i>Vitis vinifera</i>) and has been frequently isolated from apparently healthy clusters of grapes in Chile. The objectives of this study were to identify patulin-producing strains of <i>Penicillium</i> associated with winegrapes and wineries in Chile and to determine the potential presence of patulin in wines made with grapes infected with <i>P. expansum</i>. In this study, <i>P. brevicompactum, P. expansum,</i> and <i>P. glabrum</i> were identified on apparently healthy grape clusters and in the air of vineyards and wineries. Of 132 <i>Penicillium</i> isolates, 4 <i>P. brevicompactum</i> and 11 <i>P. expansum</i> strains were patulin-producing, determined by HPLC-UV/DAD. Patulin was also detected in Cabernet Sauvignon musts produced with grapes contaminated with a patulin-producing strain of <i>P. expansum.</i> However, patulin concentrations decreased during fermentation by 67.3 to 83.3%. Overall, the frequency of <i>P. expansum</i> isolation from grapes was relatively low; thus, considering the rapid degradation of patulin produced during fermentation, the risk of patulin contamination of bottled wine appears to be low.