الفهرس 
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Abstract
To improve the hygienic quality of ripened Domiati cheese produced in some traditional low technology dairy plants our study was divided into two parts. The first part investigated the impact of raw materials and processing techniques on the microbiological quality of Egyptian Domiati cheese. In which, three hundred random composite samples were collected from three traditional factories at Fayoum Governorate, Egypt. Collected samples represented twenty-five each of: raw milk, table salt, calf rennet, microbial rennet, water, environmental air, whey, fresh cheese, ripened cheese & swabs from: worker’s hands; cheese molds & utensils and tanks. All samples were examined microbiologically for Standard Plate Count (SPC), coliforms count, Staphylococcus aureus (S. aureus) count, total yeast & mould count, presence of E. coli, salmonellae and Listeria monocytogenes (L. monocytogenes). Regardless the quality of used raw materials and the processing techniques, ripening period seemed to have significant effect on improving the quality of the final product through the prevailed adverse conditions. The diverse of microorganisms and their counts in raw materials, food handlers and food contact surfaces, besides, the processing conditions have impact on the quality and safety of the product.
The second part studied the effect of some improved processing techniques on the microbiological and sensory quality of Domiati cheese. Different trials were made to overcome the common defects that usually occur, as well as to improve the microbiological quality of the produced cheese without affecting the final product organoleptic quality. Trials include use of raw-, pasteurized- and cultured pasteurized milk for cheese making, accompanied with or without sanitizing of equipment with 0.25% hydrogen peroxide, or adding 0.1% potassium sorbate as a preservative to milk. 3 trials were made for different treatments. Samples from fresh and ripened produced cheese from different treatments were examined microbiologically and organoleptically. Pasteurization of raw milk positively affected the microbiological quality, but negatively affected the organoleptic parameters of cheese. The use of cultured pasteurized milk improved both the microbiological and sensory parameters of ripened final product. Sanitizing of food contact surfaces with hydrogen peroxide improved the microbiological quality of the produced cheese. However, it negatively affects the overall acceptability of the organoleptic parameters. Addition of potassium sorbate 0.1% found to be effective in controlling the microbial growth with no effect on final product sensory parameters. Domiati cheese makers are recommended to use cultured pasteurized milk with addition of potassium sorbate, as they not only had a nearly similar sensory parameters to that arise from raw milk cheese but also more safer to the consumer. Recommendations were given to Domiati cheese manufacturers to save them from economic losses, as well as, to safeguard the consumer’s health through production of high quality and safe products.