Occurrence of Ochratoxin A–Producing Fungi in Grapes Grown in Italy

Abstract

A study was carried out to investigate fungi present on grapes grown in Italy. Aspergillus and Penicillium spp. isolates were identified and studied in vitro, and their ability to produce ochratoxin A (OA) was investigated. The survey involved nine vineyards, three located in northern Italy and six located in southern Italy. In 1999 and 2000, bunches of grapes at different growth stages were collected from all nine vineyards, and berry samples were placed in moist chambers and incubated. The resultant fungal colonies were then transferred to petri dishes containing Czapek yeast agar and incubated at 25 degrees C for 7 days; the fungal isolates were identified and then cultivated in liquid Czapek yeast medium and evaluated for their ability to produce OA. During the survey, 508 isolates were collected, with 477 belonging to Aspergillus spp. and 31 belonging to Penicillium spp. Among the aspergilli, species of the Fumigati, Circumdati, and Nigri sections were identified, with species of the Nigri section (464 isolates) largely predominating; for species of the Nigri section, 108 isolates were uniseriate, 270 were biseriate, and 86 were identified as Aspergillus carbonarius. Black aspergilli isolated over the 2 years of the study showed a very similar pattern. On average, the biseriates represented about 60% of the isolates collected in both years and were followed by uniseriates (21%) and A. carbonarius (19%). The most toxigenic strains proved to be those of A. carbonarius; about 60% of these isolates were OA producers and produced the highest levels of OA. A. carbonarius was more frequent in the south, but in both areas the percentages of OA-producing isolates remained the same.

Managing ochratoxin A risk in the grape-wine food chain

“…The incidence of colonised berries is more closely related to seasonal conditions during the year of cultivation than the grape growth stage (Battilani et al 2003b; Leong et al 2006a;Cozzi et al 2007). …”

“…Good agriculture and manufacturing practices are currently under discussion by Codex Alimentarius for the adoption of a code of practice for the prevention and reduction of OTA contamination in wine, based on a code of sound vinicultural practices adopted by the Organisation Battilani et al 2003b;Leong et al 2006a). The taxonomy of this Section is still not completely resolved, especially within the A. niger ''aggregate'' (a group of morphologically indistinguishable species), often leading to misidentification of the species distribution in food.…”

Aspectos relacionados à presença de fungos toxigênicos em uvas e ocratoxina A em vinhos

“…Ocasionalmente, em uvas, foram detectadas cepas produtoras de OTA de outras espécies de Aspergillus, em particular da secção Circumdati (particularmente A. ochraceus) (ROSA et al, 2002;BATTILANI et al, 2003;BAU et al, 2005). Essas espécies, entretanto, não são relevantes para a contaminação das uvas dada a sua baixa frequência.…”

New Strategies for Tracing Foodstuffs: Biological Barcodes Utilising PCR-DGGE

“…4 Undesirable microorganisms present on coffee beans before and/or during transformation can cause detrimental, sensorial or chemical defects. Fungi are responsible for coffee diseases (mildew and black rot), 48 mycotoxin production, [49][50][51] or sensorial defects in coffee such as musty or earthy aromas. 52 Knowledge of the structure and diversity of the fungal communities of coffee beans would lead to a better understanding of the emergence of defects in coffee in relation to the fungi present on coffee beans.…”