Use of lactic acid in Preserving local cheeses which Product from Microbial extracted Buffalo milk and identified by HPLC technology
The study aimed to extract lactic acid from alternative and cheap sources rich in carbon and nitrogen sources by using lactic acid bacteria and using the produced acid as a preservative in dairy products such as soft cheese and extending its shelf life. Two ideal isolates L. paracasei and L. helvaticus were selected based on phenotypic and biochemical examinations, 16S rRNA test and the isolates recorded lactic acid production of 64.52 and 53.08 mg.l-1 respectively, using optimum conditions 7% molasses, 4% inoculum volume, at pH 6.9, at 38°C, 40% Whey Medium for 48 Hours. Lactic acid was used in different concentrations (0.5, 0.7, 0.9%) in preserving local soft cheese made from buffalo milk for 15 and 30 days at a temperature of 4 °C. Where the concentration of 0.9% recorded a significant superiority over the rest of the concentrations by registering the lowest microbial number at the end of preservation at 30 days, as the sample was completely free of aerobic bacteria compared to the control sample, which amounted to 122103 cells/gm cheese, while the number of psychotropic bacteria reached 89105 cells/g of cheese compared to a control sample that recorded 160105 cells/gm of cheese.The results of the sensory evaluation showed a significant superiority of the sample of soft cheese to which lactic acid was added at a concentration of 0.9%, compared to the control sample, by recording the highest scores through the characteristics of color, smell, taste, and general acceptance.