Incidence of fungi in kareish cheese from raw milk and trial to control them.

Abstract

This study aimed to evaluate the incidence of fungi in kareish cheese and trial to control it. Seventy five Kareish cheese samples were collected randomly from supermarkets, groceries, small dairies and street-vendors at Gharbia Governorate for mycological examination. In addition, kareish cheese was manufactured in laboratory with addition of natamycin (0.02%, 0.015%), chitosan (1.5%, 1%) and thyme oil (1.5%, 1%) and check the quality of these cheeses during storage period. The obtained results revealed that all examined kareish cheese samples were contaminated with moulds and yeast with a mean count of 2.3×105 ±2.6×104 and 1.5x106 ± 8.4x105 cfu/g, respectively. The profile of the genera of mould isolated from kareish cheese samples were Aspergillus spp 124 (42.8%), Penicillium spp 49 (16.8%) , Phoma sorghina 15 (5%), Mucor 7 (2.4%), Nigrospora oryzae 2 (0.6%), Cladosporium cladosporidies 16 (5.5%), Chaetomium Brasiliense 4 (1.3%) Byssochlamys nivea 3 (1%), Colletotrichum gloeosporioidides 2(0.6%). Geotrichum candidum 70 (24%). The frequency distribution of yeast isolated from the examined kareish cheese samples were Candida 24.8%, Rhodotorulla 15%, Saccharomyces 13.5%, Debromyces hansenii 14.7%, Trichosporon 5.6%, Yarrowia lipolytica16.8%, Cryptococus spp. 2.2% and Torulopsis spp. 5.6%. The results of this study showed that manufactured cheese containing natamycin and chitosan had better effect on organoleptic properties and total mould count than cheese containing thyme oil.