Penicillium species during the manufacturing and ripening of Armada raw goat's milk cheese:: identification, characteristics and in vitro potential toxins production

The species and characteristics of the moulds of the Penicillhm genus were studied throughout the manufacturing and ripening of Armada cheese. Along the ripening of four batches of cheese, samples of milk, curd, and 1-, 2-, 4-, 8-, and 16-week-old cheese were studied. Of the 274 isolates obtained from the Oxytetracycline Glucose Yeast-Extract Agar medium throughout the manufacturing and ripening, 28 were considered moulds belonging to the Penicillium genus and were identified using both morphological and physiological tests as following: Penicillium roqueforti (10 strains), P. crustosum (6 strains), P. commune (4 strains), P. aurantiogreiseum (3 strains), P. verrucosum chemotype I (2 strains), and P. chrysogenum (3 strains). The presence of the species of the Penicillium genus was more important in the last stages of ripening. This fact could be related to the marked increase in the content of total free fatty acids, and of shea-chain fatty acids in particular, which is observed after the second month of ripening in this cheese. The mycotoxin production was investigated by thin-layer chromatography techniques. All the strains were toxigenic in vitro. (C) Inra/Elsevier, Paris.