Analysis of the kefir and koumiss microbiota with the focus on certain functional properties of selected lactic acid bacteria

Cilj ovog rada bio je odrediti mikrobiotu komercijalno dostupnog kefira, kumisa i kefira proizvedenog u kućnoj radinosti primjenom metagenomičke analize te usporediti neka probiotička svojstva bakterija mliječne kiseline izoliranih iz tih napitaka sa sojem Lactobacillus casei koji se koristi u proizvodnji yakulta. Kao uzorci korišteni su jedan kefir iz kućne radinosti, pet komer¬cijalno dostupnih kefira različitih proizvođača i jedan kumis. Mikrobna raznolikost kefira i kumisa određena je metagenomičkom analizom na ciljano područje V1-V2 16S rRNK gena. Direktnom izolacijom DNK utvrđeno je da su u komercijalno dostupnim uzorcima kefira dominantne vrste Streptococcus thermophilus i Lactococcus lactis. Izolacijom na MRS agaru dominantnim su se pokazali Lc. lactis i Leuconostoc mesenteroides, dok je izolacijom na M-17 agaru dominantna vrsta bila Lc. lactis. U kefiru iz kućne radinosti koji je proizveden pomoću kefirnih zrnaca, dominantna vrsta bio je Lb. kefiranofaciens. Lb. kefiri i Enterococcus durans pokazali su se dominantnim vrstama izolacijom na MRS I M-17 agaru. Lb. kefiranofaciens, Lb. kefiri, i Str. thermophilus su bile dominantne vrste u kumisu. Mikroorganizmi izolirani iz kumisa pokazali su osnovna probiotička svojstva slično bakteri¬jama mliječne kiseline izoliranim iz yakulta. Ovo istraživanje daje prikaz bakterijske mikroflore i probiotičkih svojstava bakterija mliječne kiseline izoliranih iz kefira i kumisa koji se konzumiraju u Turskoj.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

Učinak različitih metoda standardizacije suhe tvari na mineralni sastav jogurta

Yoghurt is a good dietary source of macro and micro minerals. However, the mineral content of yoghurt can vary according to the technological processing used in its manufacture. In this context, the aim of this study was to compare some macro (Ca, K and Mg) and micro (As, Cd, Co, Fe, Mn, Ni, Pb, Se, V and Zn) mineral contents of total solids-standardized yoghurts with four different methods by following: (1) Addition of skim milk powder to milk, (2) Concentration of yoghurt milk by vacuum evaporation, (3) Concentration of yoghurt curd in a cloth bag and (4) Concentration of yoghurt curd by mechanical centrifugation. The highest content of the macro minerals was in the yoghurt produced with method 1, while the highest content of most of the micro minerals was in the yoghurt produced with method 4. The results of this study showed that the mineral content of yoghurt could be modified by the method used in the manufacture of yoghurt to standardize total solids content.Jogurt je dobar prehrambeni izvor makro i mikro elemenata. Međutim, udio mineralnih tvari u jogurtu može varirati ovisno o tehnološkoj obradi koja se koristi pri njegovoj proizvodnji. U skladu s tim, cilj ove studije bio je usporediti sadržaj nekih makro (Ca, K i Mg) i mikro (As, Cd, Co, Fe, Mn, Ni, Pb, Se, V i Zn) elemenata u suhoj tvari jogurta standardiziranom primjenom sljedeće četiri metode: (1) dodavanjem obranog mlijeka u prahu; (2) koncentriranjem mlijeka uparivanjem u vakuumu; (3) koncentriranjem koaguluma jogurta u sirarskoj vreći; i (4) koncentriranjem koaguluma jogurta mehaničkim centrifugiranjem. Najveći sadržaj makro elemenata utvrđen je u jogurtu proizvedenom metodom 1, dok je najveći sadržaj većine mikro elemenata utvrđen u jogurtu proizvedenom metodom 4. Rezultati ove studije pokazali su da se sadržaj mineralnih tvari u jogurtu može podešavati primjenom različitih metoda standardizacije suhe tvari

Physicochemistry, microbiology, fatty acids composition and volatile profile of traditional Söğle tulum (goat’s skin bag) cheese

Abstract Söğle cheese is a type of traditional tulum (goat’s skin bag) cheese produced from goat’s milk or a mixture of goat’s and sheep’s milk in Küçük Söğle and Büyük Söğle villages, Antalya, Turkey. This is the first study that aimed to investigate the physicochemistry, microbiology, fatty acids composition and volatile profile of traditional Söğle cheeses ripened in goat’s skins for three months in wells. The pH and titratable acidity values, total solids, fat, protein and salt contents of the Söğle cheese samples ranged from 4.9 to 5.5, from 1.4 to 2.6%, from 46.5 to 55.0%, from 2.0 to 4.5%, from 34.9 and 42.2% and from 4.1 to 8.2%, respectively. The highest proportion of fatty acids in all cheese samples was palmitic acid (C16:0). The lactobacillus, lactococcus, total aerobic mesophilic bacteria and yeast and mold counts in the cheese samples were found to be between 7.1 and 8.5 log cfu/g, 7.8 and 8.7 log cfu/g, 7.6 and 8.5 log cfu/g and 1.0 and 4.8 log cfu/g, respectively. Fifty-three volatile components were identified in the cheese samples including 13 esters, 7 ketones, 5 acids, 2 aldehydes, 5 alcohols, 12 terpenes, and 9 miscellaneous compounds. Ketones and terpenes were the predominant volatile compounds