title: Ochratoxin A and ochratoxigenic Aspergillus species in Argentinean wine grapes cultivated under organic and non-organic systems.
abstract: The evolution of contamination with Aspergillus section Nigri and ochratoxin A occurrence was evaluated in four vineyards located at Mendoza province, Argentina during 2003-2004. The survey included two grape varieties, one of late maturation (Bonarda) and the other of early maturation (Tempranillo). The vineyards were set under non-organic and organic cropping systems. Bunches of grapes at different growth stages were collected, and berries (50 by sample) were plated on Petri dishes containing Dichloran 18% Glycerol Agar (DG18) and Dichloran Rose Bengal Chloramphenicol Agar (DRBC) media. After an incubation period of 7 days at 25 degrees C+/-1 degrees C, the mycoflora belonging to Aspergillus section Nigri was identified. The ability to produce ochratoxin A (OTA) by the potential ochratoxigenic species was evaluated on YES (2% yeast extract, 15% sucrose) medium. The cultures were incubated at 30 degrees C+/-1 degrees C for 10 days in darkness. The OTA content of the grapes was determined by HPLC. Through the different growth stages, from setting to harvest, grape contamination by the Aspergillus species, section Nigri increased. The main species isolated belonged to the A. niger aggregate. From 246 strains evaluated 24% was ochratoxigenic. OTA was not detected in grapes during the survey.
authors.affiliation: Departamento de Microbiología e Inmunología, Facultad de Ciencias Exactas, Físico, Químicas y Naturales, Universidad Nacional de Río Cuarto, Ruta Nacional No 36 Km 601, (5800) Río Cuarto, Córdoba, Argentina.
authors.forename: Ma Lorena
authors.initials: ML
authors.lastname: Ponsone
authors.forename: Mariana
authors.initials: M
authors.lastname: Combina
authors.forename: Ana
authors.initials: A
authors.lastname: Dalcero
authors.forename: Sofía
authors.initials: S
authors.lastname: Chulze
mesh_terms: D000383:Agriculture / Q000379:methods*; D001118:Argentina; D001230:Aspergillus / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification / Q000378:metabolism*; D002273:Carcinogens / Q000032:analysis; D003257:Consumer Product Safety; D003470:Culture Media / Q000737:chemistry; D005506:Food Contamination / Q000032:analysis*; D006801:Humans; D009793:Ochratoxins / Q000032:analysis / Q000096:biosynthesis*; D010802:Phylogeny; D013696:Temperature; D013997:Time Factors; D027843:Vitis / Q000737:chemistry / Q000382:microbiology; D014920:Wine / Q000032:analysis
chemical_list: D002273:Carcinogens; D003470:Culture Media; D009793:Ochratoxins; C025589:ochratoxin A