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The current study aimed to determine the bacterial microbiota of five commercial and one traditional kefir beverages consumed in Turkey. In all samples, Firmicutes (93.66%-99.98%) were the most abundant filum. Actinobacteria were detected (6.19%) in one commercial sample, and Proteobacteria were detected (5.91%) in the traditional kefir beverage. The dominant family in all commercial kefir beverages was Streptococcaceae (89.12-99.83%), and the most common genus was Lactococcus in three samples and Streptococcus in the other two samples. However, Lactobacillaceae (36.68%) and Streptococcaceae (36.68%) were dominant in traditional kefir. Lactococcus, Streptococcus and Enterococcus were common in all samples.

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Öz Amaç: Starter kültür kullanılmadan üretilen kaşar peynirlerin olgunlaşma süresince kimyasal ve mikrobiyolojik özelliklerinde meydana gelen değişimin araştırılması amaçlanmıştır. Gereç ve Yöntem: Peynir üretimi için kullanılan çiğ inek sütü yağ oranı %3.0'e ayarlandı, 37˚C'ye ısıtılıp enzim ilave edildi. Pıhtı işleme, baskı ve fermantasyon işlemi aşamasından sonra parçalama işlemi yapılarak %0.1 eritme tuzları ve %1.5 kaya tuzu ilave edildi. 65˚C'de 5 dakika eritme işlemi yapılarak peynir üretildi. Peynir vakumla paketlendi, 8˚C'de 90 gün süreyle olgunlaştırıldı. Peynir örneklerinde kurumadde gravimetrik yöntemle, yağ Gerber Metodu ile tuz Mohr yöntemi ile ve titrasyon asitliği % laktik asit olarak belirlendi. pH değerleri Nell marka pH metre ile ölçüldü. Bütün numuneler TAMB, LAB, koagulaz (+) Staphylococcus aureus, Koliform bakteri, Maya-Küf yönünden incelendi. Tüm örnekler istatistiksel olarak değerlendirildi. Bulgular: Tüm peynirler 8˚C'de 90 gün süreyle olgunlaştırıldı ve olgunlaştırmanın 1., 30., 60. ve 90. günlerinde peynirlerin kimyasal ve mikrobiyolojik analizleri yapıldı. Peynirlerin ortalama pH değerleri 5.62-5.76, asitlik %0.55-0.83 L.a., kurumadde %54.93-58.04, tuz %1.22-1.37, kurumaddede tuz %2,21-2,45, yağ %23,67-25,33 ve kurumaddede yağ %41.20-45.46 arasında tespit edildi. Mikrobiyolojik sayımlarda elde edilen veriler ise TAMB 5.17-5.75 log kob/g, LAB 5.49-6.98 log kob/g, Maya-Küf sayısı 3.66-4.88 log kob/g şeklinde bulundu. Araştırmada Staphylococcus aureus ve Koliform grubu bakteriye rastlanılmadı. Sonuç olarak üretilen peynirlerin titrasyon asitliğinde önemli farklılık bulundu (P<0.05). Fakat kurumadde, yağ, tuz ve mikrobiyolojik sonuçlar üzerinde olgunlaşma süresince istatistiki olarak fark tespit edilmedi.Öneri: Kaşar peyniri üretiminde starter kültür kullanılmadan üretim yapılabileceği ve olgunlaşma sağlanabileceği ifade edilebilir.Anahtar kelimeler: Kaşar peyniri, starter olmayan laktik asit bakterileri, kimyasal, mikrobiyolojik. AbstractAim: It is aimed to research the change in chemical and microbiological properties of Kashar cheese produced without starter culture during ripening period. Materials and Methods:Fat rate of the raw cow milk was set as 3.0% and was heated to 37˚C and enzyme was added. After coagulum processing, press and fermantation stages, 0.1% of emulsifying salts and 1.5% of salt was added. Cheese was produced through a five-minute melting process at 65˚C. Cheese was packaged by vacuuming and was ripened at 8˚C for 90 days. In samples, dry matter was conducted with gravimetric, fat with Gerber, salt with Mohr and titration acidity with % lactic acidity. pH levels were tested by Nell pH meter. Samples are examined and evaluated statistically from the point of the TAMB, LAB, coagulase (+) S. aureus, coliform bacteria and mould and yeast.Results: Cheeses were ripened at 8˚C for 90 days and analyses were exercised on ripening period. According to results, pH value was found between 5.62-5.76, acidity 0.55-0.83L.a., dry matter 54.93-58.04%, salt 1.22-1.37%, salt in dry mat...

In this study Halloumi cheese samples were produced from 1:1 mixtures of ewe's and cow's milk. Cheese samples were divided into two groups. Samples of the first group were dry salted and then vacuum packed. Next group samples were ripened in tin packs containing brine solution of 13% salt content. The changes in chemical, microbiological and sensory properties of the samples were investigated during the ripening period. It was found that the samples of the first group had higher dry matter and fat contents and acidity values but lower salt and ash contents than the samples of second group. It was also observed that salt and ash contents and acidity values increased in both groups during the ripening period while pH values decreased. In microbiological view, coliforms, total viable, yeast and mould counts were higher in the first group than in the second one. Coliforms decreased in both groups during the ripening period. On the other hand, total viable, yeast and mould counts decreased in second group. According to sensory evaluations, the first group samples were more preferred. The yield of cheese was determined as 15.40%.

The aim of this research was to determine the microbiota of commercial kefir, koumiss and homemade kefir samples using metagenomic analysis and compare some probiotic properties of lactic acid bacteria isolated from these beverages and Lactobacillus casei, used in yakult production. One koumiss, 5 commercially available kefir beverages with different brands, and 1 homemade kefir were used as samples. Microbial diversity of kefir and koumiss samples were determined by metagenomic analysis, targeting V1-V2 region of 16S rRNA gene. Streptococcus thermophilus and Lactococcus lactis were detected as dominant in direct DNA isolation from commercially available kefir beverages. Lc. lactis and Leuconostoc mesenteroides were dominant in MRS agars, and Lc. lactis were dominant in M17 agars. In kefir beverages produced by kefir grains, Lb. kefiranofaciens was determined as the dominant bacteria. Lb. kefiri and Enterococcus durans were found dominant in MRS and M17 agars respectively. Lb. kefiranofaciens, Lb. kefiri, and Str. thermophilus were the dominant bacterias of koumiss beverages. Microorganisms isolated from kefir and koumiss beverages were found to exhibit basic probiotic properties, similar to the lactic acid bacteria isolated from yakult. This research presented bacterial microflora and probiotic properties of lactic acid bacteria isolated from kefir and koumiss beverages consumed in Turkey.

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This study determined changes in the live lactic microflora of cow and goat milk kefirs, traditionally produced using kefir grain and freeze stored for 30 days, using high‐throughput sequencing. In kefir grains, 71.29% Lactococcus, 16.27% Enterococcus, and 12.3% Serratia were found in the M17 agar, and 69.93% Lacticaseibacillus and 24.54% Lactobacillus were found in MRS agar. In the M17 agar of cow milk kefir, 78.26% Lactococcus was found on day 0, and this rate was 91.68%, 87.98%, and 88.14%, on the 7th, 14th, and 30th days, respectively. As for goat milk kefir, Lactococcus levels were 82.98%, 93.28%, 87.77%, and 84.92%, respectively. On the MRS agar in cow milk kefirs, Lacticaseibacillus levels were found as 56.98%, 61.21%, 87.54%, and 75.50%, on days 0, 7, 14, and 30 of storage, respectively, while the rates were 48.95%, 77.02%, 87.85%, and 83.38% for goat milk kefirs, respectively. As a result, although kefir beverages frozen at −25°C contain sufficient levels of Lactobacillus and Lactococcus, it has been determined that the genus Serratia, which is one of the main spoilage factors in dairy products, is also increasing. Novelty impact statement In this study, the changes in the living lactic microflora during the frozen storage of traditional kefir beverages, whose production is increasing, were determined by high‐throughput sequencing. It is thought that it is important to determine the effect of the freezing process on the viability of lactic acid bacteria, which are thought to have probiotic properties, for the long‐term storage of these beverages. However, while lactic acid bacteria maintain their viability, it should be taken into account that microorganisms that are resistant to freeze conditions and cause spoilage can also develop.