摘要：The present study examined the effect of partially purified hen egg white Lysozyme as a natural antimicrobial to prolong the shelf life of soft cheese. The mentioned enzyme with enzymatic activity equal to 39 unit/mL was added in two concentration 250 and 300 mg/kg curd of soft cheese made from buffalo milk treatments T1 and T2, respectively. Treatments cheese and control cheese (C) were storage for 15 days at 6±1°C. The results revealed that there were a significant differences in chemical composition between control and treatments of Iraqi Soft Cheese (ISC) at zero time, also the enzyme contributed clearly to reduce the development of total count of bacteria also the count of psychrophilic bacteria and yeast and mold in treatments cheese during storage, treatment T2 gave better result, in prolonged the shelf life of ISC as a regard to bacterial count and also to the results of the chemical analysis for protein degradation expressed as the percentage of non-protein nitrogen (NPN) from the total nitrogen (TN) (% NPN/TN), as well as fat degradation expressed as acid degree value (ADV) during storage and retained good quality all the periods of storage (15 days) according to the broader for BDI method compared with control cheese (C), which became outside the broader of acceptance after 3 days of storage. These results reflected on sensory evaluation result for T1 and T2 treatments which get the acceptance and the highest score along the period of storage.
