This study was aimed to extract milk-clotting enzyme from sunflower seeds and to determine its potentiality for manufacturing white soft cheese from cows and goats milk. The seeds were blended and extracted using two types of buffers and milk-clotting and proteolytic activities were evaluated. The enzyme was partially purified using ammonium sulfate fractionation techniques. Results indicated that sunflower seeds extracted with 5% NaCl in 50 mmol/L acetate buffer, pH 5.0, had the highest milk-clotting activity (MCA) and lowest coagulation time compared to that extracted with only acetate buffer (pH 5.0). Ammonium sulfate at 30-50% saturation purified the enzyme to 4.3 folds with MCA of 241.0 U/mL and final enzyme yield of 10.9%. The partially purified enzyme was characterized by SDS-PAGE that showed two bands with molecular weight of 120 and 62 kDa. When compared with other plant enzymes, the partially purified sunflower enzyme was found to have higher milk-clotting activity and lower proteolytic activity. Also, both milk sources and enzyme types significantly affected the cheese yield and curd formation time. The cheese made from cow milk using sunflower enzyme had higher yield compared to that obtained using commercial rennet, whereas the opposite was observed when using goat milk. 734

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Cheese is a product that made from the curd obtained from milk by coagulating the casein with the help of rennet or similar enzymes in the presence of lactic acid microorganism (Ramakant, 2006). The diversity of cheesemanufacturing protocols, ripening regimens, and composition makes cheese a complex subject microbiologically. Romi cheese is fermented hard cheese manufactured from raw cows and buffalo's milk. As a result of moulds growth mycotoxins may be produced in cheese, rendering it unfit for human consumption (Pitt and Hocking, 2009). Romi cheese has been introduced to Sudanese

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The study was conducted to study the quality characteristics of white cheese in Khartoum State, 60 samples of white cheese (30 samples from each plastic and paper packs) were collected randomly from three different areas (Khartoum North, Omdurman and Khartoum) in Kharoum state. The manufacture date of cheese samples was defined to fixed date. Cheese samples were examined for chemical composition and microbial contents under different packing materials. The packaging materials significantly affected the chemical composition of the white cheese samples (P< 0.01) the higher (24.23 ± 1.10 %) fat content was in plastic pack. The fat (14.62 ± 0.98 %) was higher in plastic pack, also the results showed that protein, total solids, titratable acidity and the ash contents were higher in the cheese samples in plastic pack. However, volatile fatty acids were higher (7.06 ± 0 .21) in paper pack in comparison with plastic pack. The mineral contents (Calcium, Phosphorus and Potassium) were significantly higher in plastic pack. The high total bacterial count was found in cheese samples in paper pack (5.47 ± 0.76 cfu/ml). The results indicated that presence of yeast and molds, Staphylococcus aureus, E. coli and coliforms were found in white cheese samples in different packing materials (15%, 8%, 1% and 1%, respectively), with average counts (2.4 -2.7 Lg cfu/ml), (2.5 -2.8 Lg cfu/ml), (0.0 -3.0 Lg cfu/ml) and (0.0 -5.0Lgcfu/ml) respectively. Salmonella spp and Listeria monocytogenes were not detected in all cheese samples.