MYCOTOXIGENIC FUNGAL CONTAMINANT OF PROCESSED CHEESE AND DRIED MILK

Document Type : Original Article

Authors

1 Food Hygiene and Control Dept., Fac. of Vet. Med., Mansoura Univ.

2 Food Hygiene and Control Dept., Fac. of Vet. Med., Kafrelsheikh Univ.

Abstract

A total of one hundred and twenty random samples of processed cheese and dried milk were examined for incidence of mycotoxigenic moulds.
The result show that processed cheese samples contained 95.7% moulds with a mean count of 2.25x103 cfu/g while 78% of dried milk samples had mould counts with a mean value of 3.69x102 cfu/g.
Aspergillus, Penicillium, Fusarium, Alternaria, Cladosporium, Paecilomyces and Mucor was isolated from the examined samples. Aspergillus and Penicillium species predominate all species isolated.
Aspergillus spp. were isolated from 34.3% of processed cheese samples and identified as A. niger (17.9%), A. candidus (7.5%), A. flavus (6%), A. ochraceus (6%), A. wentii (3%), A. versicolour (1.5%), A. terres (1.5%), A. penicilloid (1.5%) and A. fumigatus (1.5%), while Asperigillus spp. isolated from 17.94% of dried milk samples were identified as A. niger (5.1%), A. flavus (10.3%) and A. fumigatus (2.7%).
Moreover, Penicillium spp. were isolated from 11.9% of processed cheese samples and identified into P. verrucosum, P. expansum, P. rogueforti and P. camemberti by incidence percentage of (3%) for each, while Penicillium spp. were detected in 28.2% of dried milk samples and  identified as P. verrucosum in (28.2%), P. chrysognum (5.1%) and P. Expansum (2.6%)  of examined samples.
A total of eleven A. flavous strains were screened for their ability to produce aflatoxin B1 in liquid synthetic medium (YESB) and viewed visually on TLC plates. Three strains were toxigenic, one from processed cheese and two from dried milk samples.
The public health importance of moulds and alfatoxins as well as recommendations concern with production, handling and storage of dairy products were discussed.

Keywords

Main Subjects