Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Quality Characteristics of Traditional Sepet Cheese(Izmir Institute of Technology, 2009) Ercan, Duygu; Korel, FigenInvestigation and registration of traditional foods contributes to the improvement of economy and the continuation of important elements of a nation.s culinary heritage, culture. Various types of traditional cheese are present in different shape, color, taste in the world. Sepet cheese is one of the traditional cheeses produced in the Aegean region. In this study, chemical, physical, microbiological, organoleptic, and aroma characteristics of traditional sepet cheeses were investigated. The changes in the quality characteristics were examined during production and ripening periods. The natural lactic acid bacteria flora of sepet cheeses during production and ripening was identified with phenotyphic methods. As a result of chemical analysis, average chemical characteristics of traditional sepet cheeses were found as 54.33 %±5.17 total solid content, 0.82±0.05 water activity, 25.11 %±2.86 fat content, 5.58±0.43 pH, 28.99 %±2.12 protein content. According to microbiological analysis of sepet cheeses, average total aerobic, lactococci, lactobacilli, enterococci, psychrotrophic bacteria, Staphylococcus aureus, yeast, mold, coliform bacteria counts were 7.64±1.18, 7.38±1.10, 7.38±0.99, 6.99±0.99, 5.37±1.15, 1.25±1.72, 3.22±0.25, 0.95±0.96, 2.72±1.82 log cfu/g, respectively. During descriptive profile analysis, traditional sepet cheeses were described with free fatty acid, cooked, creamy, whey, animal like, sulfurous aromatic descriptives with high salty basic taste. Free fatty acids were found to be the most abundant volatile compounds of sepet cheeses and had the highest aroma intensities in volatile fraction. According to phenotypic identification, isolates were closely related to Lactococcus lactis subsp. lactis, Lactobacillus casei spp. rhamnosus, L. plantarum, heterofermentative Lactobacillus spp., Streptococcus thermophilus, Leuconostoc spp., Enterococcus durans and E. faceium.Master Thesis Quality Characteristics and Shelf-Life of 'armola Cheese(Izmir Institute of Technology, 2012) Orşahin, Hande; Korel, FigenIn this study, forty Armola cheese samples were collected from dairies located in Seferihisar, İzmir and their physicochemical, microbiological and sensorial quality characteristics were investigated. In addition, the lactic acid bacteria flora of cheese samples was identified using genotyping method (16S-rRNA gene sequencing). The average total solid, fat, and protein contents, pH value, titratable acidity, water activity and salt content of these samples were found as 37.26, 19.52, 10.87, 4.70, 0.95, 0.91, and 2.51, respectively. The average microbial counts were found as follows: Total aerobic mesophilic bacteria, 7.82; psychrotrophic bacteria, 6.98; coliform bacteria, 4.56; lactococci, 7.55; lactobacilli, 7.87; enterococci, 6.17; yeast 7.33; mold <1.00; Staphylococcus spp., 5.94; and Listeria spp., 2.94 cfu/g. The high microbial counts showed that most of these samples were produced in very poor hygienic conditions. As a result of the descriptive sensory analysis, dominant flavor were salty and sour as basic taste; however, creamy, cooked and whey tastes were as aromatics. According to genotyping identification results, the dominant bacteria were found as Enterococcus ratti, Enterococcus durans, Enterococcus hirae, Streptococcus lutetiensis, Streptococcus equines, Streptococcus luteciae, Lactobacillus paracasei subsp. tolerans, Lactobacillus casei subsp. casei, Lactobacillus zeae, and Lactobacillus paracasei subsp. paracasei. Due to the short shelf-life of Armola cheese, antimicrobials, Nisaplin®, Natamax®, and Microgard TM 100, were also used alone or in combination to extend the shelf-life of the product. Microbiological, sensory, color and pH analyses were conducted during storage. Because of the inhibition effects on yeasts, Natamax® and its combinations were the most effective on extending the shelf-life.