Detection of Molds in Egyptian Ras Cheese with Special Reference to Aspergillus flavus Aflatoxins

Ras cheese is the most common hard cheese in Egypt. It is usually produced from raw cow milk and ripened in unhygienic conditions; this may promote the growth of molds. This study was conducted to determine the contaminant molds in different samples of Egyptian Ras cheese and detect the level of fungal toxins as AFM1 and AFB1 in positive Aspergillus flavus samples. A total of 150 Ras cheese samples (recent, medium and old, 50 for each) were collected randomly from different dairy shops and supermarkets, located in Sohag Governorate, Egypt. These samples were examined for total mold counts. The results revealed that the mean total mold count in recent, medium and old Ras cheese samples were 41× 105 ±14× 105, 12× 106 ±1.9× 106 and 48× 106 ±5.9× 106 CFU/g, respectively. All samples were exceeded the permissible limits of total mold counts established by Egyptian standard (ES). Aspergillus was the most predominant genus and represented by eight species namely A. flavus, A. niger, A. fumigatus, A. nidulans, A. brasiliensis, A. ochraceus, A. parasiticus and A. terreus. The incidence of A. flavus samples in recent, medium and old Ras cheese samples were 22, 25 and 37, respectively. All positive A. flavus samples were exceeded the permissible limits of AFB1 established by Egyptian Standard (ES). Also, 58.3 % of positive A. flavus samples were exceeded the permissible limits of AFM1 established by Egyptian Standard. Therefore, Ras cheese should be made from pasteurized milk to avoid mold contamination and their mycotoxins.