Spoilage fungi and their mycotoxins in commercially marketed chestnuts.
A nationwide survey was carried out to assess mould spoilage of Castanea sativa nuts sold in Canadian grocery stores in 1998-99. Morphological and cultural characters, along with secondary metabolite profiles derived from thin-layer chromatography, were used to sort and identify fungi cultured from nut tissue. Three mycotoxigenic fungi dominated (Penicillium crustosum, Penicillium glabrum/spinulosum and Penicillium discolor) and were isolated at frequencies of 67.1%, 18.6% and 17.7%, respectively, from a total sample size of 350 nuts. Another mycotoxin producer, Aspergillus ochraceus was also isolated, but at a much lower frequency. HPLC and diode array detection were used to confirm the suspected presence of the mycotoxins penitrem A, chaetoglobosin A and C, emodin and ochratoxin A in extracts prepared from naturally infected nut tissue. To the best of our knowledge, this is the first time emodin has been found in a naturally contaminated food source.
Overy
David P
DP
Eastern Cereal and Oilseed Research Centre, Agriculture and Agri-Food Canada, Research Branch, Ottawa, Ontario, Canada K1A 0C6. david.overy@biocentrum.dtu.dk
Seifert
Keith A
KA
Savard
Marc E
ME
Frisvad
Jens C
JC
D001235:Aspergillus ochraceus / Q000302:isolation & purification* / Q000378:metabolism; D002855:Chromatography, Thin Layer; D005506:Food Contamination / Q000032:analysis; D005516:Food Microbiology; D009183:Mycotoxins / Q000032:analysis*; D009754:Nuts / Q000382:microbiology*; D010407:Penicillium / Q000302:isolation & purification* / Q000378:metabolism
D009183:Mycotoxins