Prevalence of mould and yeast in some dairy products sold in Menofia Governorate

ABSTRACT

A total of one hundred samples [25 each] of milk powder, yogurt, cheddar cheese and Ras cheese were collected from dairy shops and super markets in Menofia Governorate. Each sample was divided into two parts, one part for mycological studies and the other part for aflatoxins. Our results revealed that, the mould and yeast could be detected in all examined samples of milk powder, yoghurt, cheddar cheese and Ras cheese with mean count values of 8.3x 10[2] +/- 0.2xl0[2], 6.9x10 +/- 0.4x 10, 5.3x 10[3] +/- 2.3x10[2 and 4.1x10[3] +/- l.6x10[2] for mould and 0.5x 10[2] +/- 1.1x10, l.4x10[2] +/- 0.5x 10[2], 6.5x10[4]0 +/- .4x10[4] and 5.4x 10[3] 1 +/- .1xl0[3] for yeasts respectively. Mould and yeast were isolated at varying percentages from all examined samples The mould genera were, Asprigallus spp, Alternana spp, Penicilhum spp, Cladosporium spp, Mucor spp and Rhizopus spp. While yeast genera were Candida spp, Rhodotorula spp, Saccharomyces spp and Torulopsis. Aflatoxin M1 residues were detected in 16%, 16%, 32% and 44% of examined milk powder, yoghurt, cheddar cheese and Ras cheese samples respectively. Aflatoxin B1 residues were detected in 12%, 52% and 48% of examined milk powder, cheddar cheese and Ras cheese samples respectively. On the other hand, Aflatoxin B2 were detected in 12%, 24% and 12% of examined milk powder, cheddar cheese and Ras cheese samples respectively. From the present investigation it could be concluded that, feeding of dairy animals with aflatoxins free feedstuff, using high quality raw milk strict hygienic measures during manufacture, packing and distribution, proper personal hygiene, adequate cleaning and sanitation of dairy equipments and proper refrigeration are vital elements in the production of high quality dairy products