UTILIZATION OF SALT WHEY FROM EGYPTIAN RAS (CEPHALOTYRE) CHEESE IN MICROBIAL MILK CLOTTING ENZYMES PRODUCTION | ||||
Journal of Food and Dairy Sciences | ||||
Article 2, Volume 3, Issue 5, May 2012, Page 299-314 PDF (1.24 MB) | ||||
Document Type: Original Article | ||||
DOI: 10.21608/jfds.2012.75391 | ||||
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Authors | ||||
E. El - Tanboly ![]() | ||||
1Dairy sciences, National Research Centre, Dokki, Cairo Egypt., | ||||
2Faculty of agriculture, El-Azhar University, Assiut, Egypt. | ||||
Abstract | ||||
Microbial milk-clotting enzymes are valued as calf rennet substitutes in the cheese industry. Mucor pusillus QM 436 was identified to produce the highest milk-clotting activity during screening of 19 fungal strains. Salted whey resulting from Ras (Cephalotyre) cheese manufacture as a whole medium for growth of Mucor pusillus QM 436 and production of the enzyme. The milk-clotting enzyme from Mucor pusillus QM 436 was purified to 7.14-fold with 54.4% recovery by precipitation in ammonium sulfate, ethanol and fractionated by gel filtration on Sephadex G-100. The enzyme was active in the pH range 5.5-7.5 and was inactivated completely by heating 5 min at 70ºC and 30 min at 65ºC. The highest level of enzyme activity was obtained at 60ºC, pH 5.5. A positive and proportional relationship occurred in presence of CaCL2 in milk, with inhibition occurred in presence of NaCl. The high level of milk-clotting activity coupled with a low level of thermal stability suggested that the milk-clotting enzyme from Mucor pusillus QM 436 should be considered as a potential substitute for calf rennet. | ||||
Keywords | ||||
Milk-clotting enzymes; Mucor pusillus QM 436; Ras cheese; Salted whey; Purification | ||||
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