市販アーモンド粉末におけるカビ分布とアフラトキシン汚染原因菌の解析

摘要

The fungal population and distribution of aflatoxin-producing fungi in 30 samples of imported almond powder products purchased from retail markets were examined in this study. Total counts of fungi ranged from under 1.0 × 10 colony-forming units (CFU)/g to 8.5 × 10~3 CFU/g as determined with the dilution plating technique. The predominant fungi in the mould-contaminated almond samples were Aspergillus niger,A. flavus and the related species, Penicillium, Cladosporium and Rhizopus. Aflatoxin-producing ability in the isolates of A. flavus and related fungi were tested by thin layer chromatography using 2% yeast extract and 15% sucrose broth culture. Four different aflatoxigenic fungi were detected in the isolates; aflatoxins B_1 and B_2 were produced by some strains of A. flavus and A. parvisclerotigenus, and aflatoxins B_1, B_2, G_1, G_2 were produced by all tested strains of A. parasiticus and A. nomius. Identification of the strains was based on morphological and metabolic characters.%アーモンド（Prunus amygdalus）は，中東地域原産のバ ラ科の落葉高木性の植物で，その果実内の種子（核果）を 食用とするナッツ類の一種である．スイートアーモンド （P.amygdalus var.dulcis）は，主としてアメリカ合衆国， カリフォルニア州で栽培されており，ビターアーモンド （P.amygdalus var. amara）は，イタリア，スペインなど のヨーロッパ諸国およびイランなどの中東地域で栽培され ている．