title: Sterigmatocystin: incidence, fate and production by Aspergillus versicolor in Ras cheese.
abstract: The occurrence, distribution, and stability of sterigmatocystin (STG) in Ras cheese were investigated. An incidence value for STG in market samples of Ras cheese was 35% with a mean value of 22.2 micrograms/kg. In experimental Ras cheese from milk contaminated with STG, 80% of the toxin was retained in the curd while 20% was found in the whey. The temperature for cheese ripening affected the toxin content. At 6 degrees C the toxin concentration was hardly affected, but at 20 degrees C the concentration was reduced by 16% after 90 days. In Ras cheese contaminated with spores of Aspergillus versicolor, toxin production started after 45 days of the ripening, reached a maximum after 90 days, and declined thereafter. Cow's milk favoured toxin formation in comparison with buffalo's milk. Aged cheese (more than 6 months) inhibited toxin production.
authors.affiliation: Department of Dairying, Faculty of Agriculture, Cairo University, Dokki, Egypt.
authors.forename: E A
authors.initials: EA
authors.lastname: Abd Alla
authors.forename: M M
authors.initials: MM
authors.lastname: Metwally
authors.forename: A M
authors.initials: AM
authors.lastname: Mehriz
authors.forename: Y H
authors.initials: YH
authors.lastname: Abu Sree
mesh_terms: D000818:Animals; D001230:Aspergillus / Q000378:metabolism*; D002020:Buffaloes; D002417:Cattle; D002611:Cheese / Q000032:analysis*; D002855:Chromatography, Thin Layer; D005506:Food Contamination / Q000032:analysis*; D005516:Food Microbiology; D008892:Milk / Q000737:chemistry / Q000382:microbiology; D013241:Sterigmatocystin / Q000032:analysis* / Q000096:biosynthesis
chemical_list: D013241:Sterigmatocystin