EFFECT OF ADDITION RAW BACTERIOCIN PRODUCED BY Lactobacillus delbrueckii Sub-Sp. bulgaricus ON SOFT CHEESE

The effect of adding raw bacteriocin produced by Lactobacillus bulgaricus to cheese curd at an amount of (5 and 10 and 15) mL/kg cheese as a biological preservative to prolong the shelf life of soft cheese, in addition to the control treatment, knowing that each 1 mL of bacteriocin filter contains 15 units/ mL of bacteriocin. The results of the physicochemical, microbial and sensory tests for cheese stored at refrigerator temperature for a period (zero) to (21) d of adding bacteriocin showed the superiority of the treatment of cheese added to 15 mL/kg cheese of bacteriocin over the rest of the other treatments during the storage period, where the acidity development decreased by 0.363 compared to Cheese with the control treatment, which was at a rate of 0.547, as well as a significant decrease in the number of microorganisms compared with the cheese treated with the control treatment, as well as a clear improvement in the sensory characteristics of soft cheese, which makes it qualified to be a biological preservative for the absence of negative effects on the properties of the obtained product.