of wine grapes in the Czech Republic in the year 2004

Transcription

1 International Workshop Marsala, Italy, 20 th 21 th October 2005 The mycobiota of wine grapes in the Czech Republic in the year 2004 Vladimir Ostry, Jarmila Skarkova, Jiri Ruprich, Ivana Prochazkova, Alena Kubatova* National Institute of Public Health in Prague, Centre for the Hygiene of Food Chains,NRC for Microfungi and Mycotoxins in Food Chains, Brno, CZ , Czech Republic *CCF - Culture Collection of Fungi, Department of Botany, Faculty of Science, S Charles University, Prague, Czech Republic

2 Czech pilot study As a response to project "WINE- OCHRA RISK" a pilot study in the Czech Republic was prepared. The aim of this study was to monitor the mycobiota of wine grapes, occurrence of ochratoxigenic microfungi in wine grapes and occurrence of ochratoxin A in grape fresh juice, must and wine from domestic crop in the year 2004.

3 Sample characterization Five vineyards with twenty two wine grape varieties were selected for the pilot study in the ZNOJMO WINE REGION N ZNOJMO Corp.) (ZNOVÍN ZNOJMO

4 ZNOJMO WINE REGION Vineyard Volne pole Vineyard Sobes

5 Sample characterization Vineyard Vineyard Wine grape variety Type of grape N o variety 1 Hosteradice 2 Miroslav 3 Podmoli 4 Dobsice 5 Horni Dunajovice Saint Laurent, Rulander (Pinot Noir) Rhine Riesling, Rulander (Pinot Blanc), Sauvignon Blanc Frankovka (Limberger) Palava, Green Veltliner Rulander (Pinot Noir) Rhine Riesling, Rulander (Pinot Blanc), Rulander (Pinot Gris), Welschriesling Frankovka (Limberger) Sauvignon Blanc, Red Traminer Frankovka (Limberger), Cabernet moravia, Saint Laurent Sauvignon Blanc, Welschriesling, Green Veltliner Red White Red White Red White Red White Red White

6 Mycological examination Five wine grape berries per bunch were randomly selected, plated onto Dichloran Rose Bengal Chloramphenicol (DRBC) agar,, and incubated for 5-77 days at 25 C.

7 Mycological examination Penicillium sp. and Aspergillus sp. were picked off onto Czapek Yeast Extract (CYA) agar, Alternaria, Cladosporium, Rhizopus and Epicoccum onto Potato dextrose (PDA) agar to obtain pure cultures and for further species identification.

8 Wine grapes processing Grape fresh juice was prepared in laboratory conditions by wringing. Must and young wine corresponding to wine grape variety were acquired and sampled in a winery Znovín Znojmo Corp.

9 Ochratoxin A determination An validated and accredited HPTLC method for quantification of OTA in grape fresh juice, must and wine has been developed Grape fresh juice, must and wine samples were purified on commercial immunoaffinity columns (Ochratest VICAM,, USA) The limit of quantification (LoQ) was 8 ng/l of grape fresh juice, must and wine.

10 Vineyard number Identified Aspergillus or Penicillium sp. Results Other species 1 - Alternaria alternata biotype 1 Alternaria alternata biotype 2 Cladosporium herbarum Epicoccum nigrum Rhizopus nigricans 2 Penicillium aurantiogriseum Alternaria alternata biotype 2 3 P. expansum P. spinulosum Alternaria alternata biotype 1 Alternaria alternata biotype 2 Cladosporium cladosporioides 4 - Alternaria alternata biotype 1 Alternaria alternata biotype 2 Cladosporium herbarum 5 P. griseofulvum, P. aurantiogriseum, P. citrinum, Aspergillus clavatus Alternaria alternate biotype 1 Alternaria alternata biotype 2 Cladosporium herbarum Rhizopus nigricans

11 Microfungi Results Alternaria alternata biotype 1 73 (16/22) Alternaria alternata biotype 2 73 (16/22) Cladosporium herbarum 41 (9/22) Rhizopus nigricans 27 (6/22) Cladosporium cladosporioides 14 (3/22) Penicillium aurantiogriseum 14 (3/22) Penicillium griseofulvum 14 (3/22) Penicillium expansum 10 (2/22) Penicillium citrinum 5 (1/22) Penicillium spinulosum 5 (1/22) Aspergillus clavatus 5 (1/22) Frequency (%) (strains/total samples) Epicoccum nigrum 5 (1/22)

12 Results Ochratoxigenic microfungi (Aspergillus carbonarius, other Aspergillus Section Nigri, Aspergillus ochraceus, Penicillium verrucosum and Penicillium nordicum) were not found in grape samples

13 Results Occurrence of OTA in grape fresh juice, must and wine was not determined (< LoQ 8 ng/l)

14 Conclusions The results of pilot study indicate that OTA incidence and concentration decrease probably in wine products /white, rosé and red/ from Northern regions in Europe and increase in wine products from more Southern /warmer/ regions

15 International Workshop Marsala, Italy, 20 th 21 th October 2005 Tante grazie per attenzione! Thank you very much for your attention!