Lactobacillus kefiranofaciens: From Isolation and Taxonomy to Probiotic Properties and Applications

One of the main lactic acid bacterial species found in the kefir grain ecosystem worldwide is Lactobacillus kefiranofaciens, exhibiting strong auto-aggregation capacity and, therefore, being involved in the mechanism of grain formation. Its occurrence and dominance in kefir grains of various types of milk and geographical origins have been verified by culture-dependent and independent approaches using multiple growth media and regions of the 16S rRNA gene, respectively, highlighting the importance of their combination for its taxonomic identification. L. kefiranofaciens comprises two subspecies, namely kefiranofaciens and kefirgranum, but only the first one is responsible for the production of kefiran, the water-soluble polysaccharide, which is a basic component of the kefir grain and famous for its technological as well as health-promoting properties. L. kefiranofaciens, although very demanding concerning its growth conditions, can be involved in mechanisms affecting intestinal health, immunomodulation, control of blood lipid levels, hypertension, antimicrobial action, and protection against diabetes and tumors. These valuable bio-functional properties place it among the most exquisite candidates for probiotic use as a starter culture in the production of health-beneficial dairy foods, such as the kefir beverage.

KEFIR DENGAN KOMBINASI SUSU SAPI DAN TEPUNG MOCAF TERHADAP pH, KADAR AIR, TOTAL PADATAN DAN PROPERTI FISIK

ABSTRAK Kefir merupakan sebuah produk olahan dalam bentuk minuman dari suatu fermentasi susu menggunakan starter berupa butir atau biji kefir (kefir grain/kefir granule) yaitu butiran-butiran putih atau krem yang memiliki kandungan Streptococcus sp, Lactobacilli dan beberapa jenis ragi atau khamir nonpatogen. Bakteri tersebut memiliki peran dalam pembentukan asam laktat, sedangkan khamir menghasilkan alkohol dan CO2. Tujuan penelitian ini adalah untuk mengetahui pengaruh kombinasi susu sapi dan tepung mocaf pada kefir dan menentukan formulasi kombinasi susu sapi dan tepung mocaf paling optimal. Penelitian ini dilakukan secara experimental menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 6 ulangan. Perbandingan antara susu sapi dan tepung mocaf adalah 100:0, 90:10, 80:20, 70:30. Parameter yang dianalisis meliputi pH, Kadar air, total padatan dan propert fisik. Hasil yang diperoleh dianalisis menggunakan uji analisis variasi ANAVA. Hail uji pada pH dan kadar air mengalami kenaikan sedangkan total padatan mengalami penurunan. Kesimpulan pada penelitian Kefir dengan kombinasi susu sapi sangat berpengaruh nyata (p<0,01) terhadap nilai pH, kadar air dan total padatan. Nilai pH mengalami kenaikan dikarenakan tingginya pati pada tepung mocaf. Peningkatan nilai kadar air dan penurunan total padatan disebabkan banyaknya air pada larutan mocaf. Hasil uji pada properti fisik ini tidak memiliki perbedaan hal ini dikarenakan tepung mocaf memiliki warna putih, aroma netral, dan rasa netral. Kata Kunci: Kefir, Tepung Mocaf, Susu Sapi, Susu Fermentasi ABSTRACT Kefir is a processed product in the form of a drink from a fermented milk using a starter in the form of kefir grains or seeds (kefir grain/kefir granule), namely white or cream granules containing Streptococcus sp, Lactobacilli and several types of non-pathogenic yeast or yeast. These bacteria have a role in the formation of lactic acid, while yeasts produce and CO2. The purpose of this study was to determine the effect of the combination of cow's milk and mocaf flour on kefir and to determine the most optimal combination of cow's milk and mocaf flour. This research was conducted experimentally using a completely randomized design (CRD) with 4 treatments and 6 replications. The ratio between cow's milk and mocaf flour is 100:0, 90:10, 80:20, 70:30. Parameters analyzed include pH, moisture content, and total solids. The results obtained were analyzed using the ANOVA variation analysis test. The test results on pH and water content increased while total solids decreased. The conclusion in the study of Kefir with a combination of cow's milk was very significant (p<0.01) on the pH value, water content and total solids. The pH value increased due to the high starch in mocaf flour. Increase in the value of water content and decrease in total solids due to the amount of water in the mocaf solution. The test results on this physical property have no difference, this is due to the white color of mocaf flour, neutral aroma, and neutral taste. Keywords: Kefir, Mocaf Flour, Cow's Milk, Fermented Milk

Storage Stability of Antioxidant in Milk Products Fermented with Selected Kefir Grain Microflora

The aim of the study was to assess the antioxidant potential of goat’s milk and whey from goat’s milk fermented with selected bacteria strains from kefir grain (L. plantarum, L. fermentum, L. rhamnosus and L. acidophilus) with regard to fermented cow’s milk with the same bacteria strains. The assessment of antioxidant potential was made by ABTS, DPPH, TPC and FRAP methods. The work also assessed metabolic activity of tested lactic acid bacteria using measurement of electrical impedance changes in the growing medium. The highest values describing the antioxidant potential were found for fermented milk by L. acidophilus. It was also found that the time of cooling storage causes significantly increasing the antioxidant potential of most analyzed samples. Metabolic activity of tested lactic acid bacteria was the highest for cow’s milk. The course of curves for goat’s milk and whey from goat’s milk was similar, which confirms the differences between cow and goat milk.

The Type and Concentration of Inoculum and Substrate as Well as the Presence of Oxygen Impact the Water Kefir Fermentation Process

Eleven series of water kefir fermentation processes differing in the presence of oxygen and the type and concentration of inoculum and substrate, were followed as a function of time to quantify the impact of these parameters on the kinetics of this process via a modeling approach. Increasing concentrations of the water kefir grain inoculum increased the water kefir fermentation rate, so that the metabolic activity during water kefir fermentation was mainly associated with the grains. Water kefir liquor could also be used as an alternative means of inoculation, but the resulting fermentation process progressed slower than the one inoculated with water kefir grains, and the production of water kefir grain mass was absent. Substitution of sucrose with glucose and/or fructose reduced the water kefir grain growth, whereby glucose was fermented faster than fructose. Lacticaseibacillus paracasei (formerly known as Lactobacillus paracasei), Lentilactobacillus hilgardii (formerly known as Lactobacillus hilgardii), Liquorilactobacillus nagelii (formerly known as Lactobacillus nagelii), Saccharomyces cerevisiae, and Dekkera bruxellensis were the main microorganisms present. Acetic acid bacteria were present in low abundances under anaerobic conditions and only proliferated under aerobic conditions. Visualization of the water kefir grains through scanning electron microscopy revealed that the majority of the microorganisms was attached onto their surface. Lactic acid bacteria and yeasts were predominantly associated with the grains, whereas acetic acid bacteria were predominantly associated with the liquor.

Changes in benzoic acid content of goat milk kefir produced using different kefir cultures

In this study, the content of hippuric and benzoic acid of goat milk kefir produced with commercial lyophilized kefir cultures and kefir grain was investigated. 9 commercial kefir culture and 1 kefir grain were used in production of goat milk kefir. Based on the obtained results, hippuric acid was not found in kefir samples during the storage period, whereas goat milk samples contained hippuric acid (14.8 mg/kg). Benzoic acid levels of kefir samples ranged from 8.5 to 26.6 mg/kg during the 28-day storage period. The highest Lactobacillus and Lactococcus counts were observed in kefir sample produced with kefir grain while this sample was one of the sample containing the lowest (11.2 mg/kg) benzoic acid levels. In conclusion, the research results showed that starter kefir cultures and microbiota used in kefir production and storage period had a significant effect on the formation of benzoic acid levels (p<0.05).

Determination of monosaccharide composition of kefiran using HPLC

Kefiran is an exopolysaccharide (EPS) produced by specific microorganisms in the kefir grain. In this research, kefir grain was activated in various carbon sources (glucose, galactose or lactose) containing medium. The monosaccharides composition of the formed kefiran were determined by a high performance liquid chromatography (HPLC). HPLC with refractive index (RI) detector was used in order to make qualitative and quantitative analysis of sucrose, glucose, galactose, arabinose, xylose, and ribose present in kefiran. Also, the physical properties of differently kefiran formed were determined. The amount of kefiran in the control group and in the sample from the galactose containing medium were determined to be 511.00 and 610.55 mg/L, respectively. The kefiran form obtained from the medium containing galactose was more positively affected than in other media. The apparent viscosity, at a shear rate of 66.0 s-1of the kefiran produced in glucose containing medium, was determined to be 29.2 mPas. The surface morphologies of different kefirans were analysed and roughness parameters were determined by atomic force microscopy (AFM); the maximum height of lumps ranged from 16.80 to 22.10 nm. In this study, of sucrose, glucose, galactose, arabinose, xylose, and ribose were found in sugar composition in all kefiran samples.

Karakteristik Fisik dan Total Bakteri Kefir Susu Kerbau yang Diproduksi pada Suhu Ruang

Pemanfaatan susu kerbau Indonesia masih sangat terbatas dan hanya diolah menjadi beberapa makanan tradisional seperti dali dan dadih serta masih sedikit yang digunakan sebagai kefir.Penelitian bertujuan untukmengembangkan teknologi pengolahan susu kerbau menjadi produk kefir. Bahan utama yang digunakan dalam penelitian ini adalah susu kerbau segar dari Sumatera Utara dan kefir grain. Waktu inkubasi yang digunakan adalah selama 48 jam dengan periode pengamatan 12 jam. Parameter yang merupakan karakteristik fisik yang diamati adalahtotal padatan, solid non fat (SNF), berat jenis, pH, dan viskositas, serta ditambah dengan pengamatan total mikroba. Data dianalisis menggunakan uji Analysis of Variance (ANOVA) dengan taraf signifikansi 5% dan apabila terdapat perbedaan maka dilanjutkan dengan uji Duncan. Hasil penelitian menunjukkan adanya peningkatan yang sangat tajam pada SNF dan berat jenis. Disamping itu, adanya penurunan terjadi pada nilai total padatan. Seiring dengan lamanya inkubasi, viskositas dan total mikroba tampak meningkat. Nilai pH tampak sangat tajam penurunannya. Kesimpulannya, kefir berhasil diproduksi pada suhu ruang dan menunjukkan adanya perubahan sifat fisikokimia serta sifat mikrobiologis yang sangat spesifik.Physical Characteristic and Total Bacteria on Kefir made of Buffalo's Milk in Room TemperatureAbstractIn recent decades, utilization of Indonesian buffalo’s milk is limited to produce traditional foods such as Dali and Dadih (traditional’s name of curd) and has not been well developed to produce kefir. This research was aimed at producing kefir that was made of buffalo’s milk. Fresh buffalo’s milk from Sumatera Utara and kefir grain were used in this research. Kefir was made from the fortification kefir grain into buffalo’s milk then this mixture was incubated for 48 hour without additional heating control or in room temperature. Total solid, solid non-fat (SNF), specific gravity, pH, viscosity were analyzed as physic parameters and total bacteria was also studied. Data were analyzed using the Analysis of Variance (ANOVA) test using a significance level of 5% Duncan test was applied when significant result was obtained. Solid non-fat and specific gravity were remarkably decrease in its value while viscosity and total bacteria showed an increase. Significant decrease was found in pH value. As conclusion, the production of kefir was successfully achieved using buffalo’s milk and showing very specific value in physico and microbial properties.