problem of red color defect in raw milk soft cheese in Egypt

ABSTRACT

Mycological examination of samples representing 337 tins packed with soft cheese "Domiatti" was done for explanation of a red color defect which is characterized by diffuse deep red color over the surfaces of raw milk soft cheese stored for four months at room temperature without any apparent colonial growth. A red color mold growth over Sabouraud dextrose agar could be isolated and identified as Monascus ruber. The suspected mold was inoculated in experimentally manufactured soft cheese and could produce the same defect. Ascospores of Monascus ruber survived pasteurization, but boiling of milk with holding time of 5 minutes destroyed these spores. Effect of storage temperatures and NaCl concentrations to prevent such defect in cheese were studied and discussed. Economical and public health importance of the isolated mold and its pigment as well as control measures for solving the problem have been discussed