Determination of microbiological and physical chemical quality of mud cheese produced by traditional method, determination of shelf life and production of probiotic additional functional mud cheese

Tire mud cheese is a traditional cheese produced in the Aegean region and is loved and consumed by the local people. In this thesis, in order to determine the present microbial flora of Tire mud cheese obtained from 4 different dairy farms, total mesophilic aerobic bacteria (TMAB), total psychrophilic aerobic bacteria (TPAB), mold yeast (K&M) lactic acid bacteria (LAB), total coliform bacteria (TCB), fecal coliform bacteria (TFCB), coagulase positive Staphylococcus, Listeria monocytogenes, Salmonella sp. were analyzed. According to TMAB, TPAB, LAB, K&M, TKB, TFKB count results, the value ranges from highest to lowest are as follow respectively TMAB was 4.99±0.08 - 4.56±0.56; TPAB was 3.16±0.81 - 3.70±0.58; LAB 3.46± 0.15 - 5.35±0.25; K&M 3.35 ± 0.10 -3.87±0.09, KB 1.75±0.20 - 2.27±0.30; TFKB 1.46 ± 0.15 - 1.91 ± 0.29 log CFU/g. The results of physico-chemical analyzes were pH 6.77±0.09 - 5.15±0.01, aw 0.92±0.01 - 0.90 ±0.03; titration acidity% (in terms of lactic acid) 0.10±0.02 - 0.08±0.01%; salt% 1.02%±0.01 - 2.20%±0.05; dry matter% 30.35%±0.43 - 27.33%±1.82; color value L * 84.37±0.17 - 71.81±0.98; a * (-2.01±0.47) - (-4.02±0.06); b * 12.90±0.54 - 13.83±0.23; ∆E 73.18±0.68 - 85.58±0.16. Coagulase positive Staphylococcus, Listeria monocytogenes, Salmonella sp. were not detected. E.coli was not found in the cheese samples, but according to the results of IMViC test Klebsiella pneumonoiae, Enterebacter aerogenes, Citrobacter freundi were detected. In the second part of the study, microbiological analysis of mud cheese produced under laboratory conditions were performed. According to the results of the microbiological analysis TMAB 3.73±0.29 - 2.70±0.34, TPAB 2.36±0.35-3.96 LAB 5.03±0.15 - 5.35±0.25 log CFU/g. In the third stage of the study, probiotic bacteria (Bifidobacterium animalis ssp lactis B94) were added to the mud cheese produced under laboratory conditions and microbiological and physicochemical properties of mud cheese without probiotic addition were compared. TMAB was found to be 2.76±0.17 - 2.70±0.34, LAB 7.24±0.05 - 5.35±0.25, while M&Y, TCB and TFCB was found to be below the values in cheese samples. The result of physico-chemical properties pH 5.50±0.93 - 5.25±0.01; aw 0.93±0.01 to 0.92±0.01; titration acidity 0.15±0.01% - 0.11±0.01%, salt% 1.89±0.01% - 1.91±0.01%, dry matter% 28.94±0.06 - 27.70±0.11; color value L* 84.37±0.17 - 81.23±1.05; a* (-4.02±0.05) - (-2.84±0.11); b* 15.80±0.32 - 13.83±0.23, ∆E 85.21±0.88 - 82.35±1.02. In the last stage of the study, cheese samples were stored at 4 °C for 30 days and subjected to microbiological and physical analyzes at certain periods (0, 1, 3, 5, 10, 20 and 30 days). After 30 days of storage, the number of TMAB was 2.70 ± 017 to 7.44 ± 0.04 log CFU/g; the number of LAB 4.21±0.05 - 7.64±0.03log CFU/g, the number of M&Y 3.35±0.10 - 6.82 ± 0.76log CFU/g, the number of TKB 2.15 ± 0.77 - 0.15 ± 0.27 log CFU/g, the number of TFK 2.72±0.28 - 1.49±0.94 log CFU/g. Physico-chemical analysis results after 30 days mean pH 6.77 ± 0.09 - 4.76 ± 0.01,% titration 0.08 ± 0.15 - 0.25 ± 0.01, aw 0.85± 0.05 to 0.93±0.06; b * 11.04±0.60 to 17.66±0.07; L * 61.15±1.03 to 87.74±1.35; a *( -1.67±0.10) - (-4.53±0.19); dry matter% 27.33%±0.18 - 37.57%±0.33; salt% 1.02 ±0.01 - 2.25±0.05. As a result, it was determined that the commercially available Tire mud cheese samples had a short shelf life, the most important factor was the unfavorable production conditions, production under appropriate conditions increased the safety and shelf life of the cheese, and both safer and functional products could be obtained by adding probiotics. KEYWORDS: Traditional cheese, Tire mud cheese, functional food