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Rosane Freitas Schwan - One of the best experts on this subject based on the ideXlab platform.
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Fermentation process for production of apple-based Kefir vinegar: microbiological, chemical and sensory analysis
Brazilian Journal of Microbiology, 2017Co-Authors: Roberta Oliveira Viana, Roberto Alves Braga, Karina Teixeira Magalhães-guedes, Disney Ribeiro Dias, Rosane Freitas SchwanAbstract:The aim of this study was to develop a Kefir apple-based vinegar and evaluate this fermentation process using new methodology with Biospeckle Laser. Brazilian Kefir grains were inoculated in apple must for vinegar production. In this study, the microbial community present in Kefir, and correspondent vinegar, was investigated using Matrix Assisted Laser Desorption/Ionization – Time of Flight Mass Spectrometry (MALDI-TOF MS) technique. Saccharomyces cerevisiae, Lactobacillus paracasei, Lactobacillus plantarum, Acetobacter pasteurianus and Acetobacter syzygii were the microbial species identified. S. cerevisiae, L. plantarum, A. pasteurianus and A. syzygii were found in smaller quantities at the beginning of the alcoholic fermentation, but were found throughout the alcoholic and acetic fermentation. Kefir grains were able to utilize apple must as substrate to produce ethanol, and acetic acid. Acetate, volatile alcohols and aldehydes in the vinegar-based Kefir were also produced. The yield of acetic acid in the Kefir vinegars was ∼79%. The acetic acid concentration was ∼41 g L−1, reaching the required standard for the Brazilian legislation accepts it as vinegar (4.0% acetic acid). Kefir vinegar showed good acceptance in the sensory analysis. The technology proposed here is novel by the application of immobilized-cell biomass (Kefir grains) providing a mixed inocula and eliminating the use of centrifuge at the end of the fermentative process. This step will save energy demand and investment. This is the first study to produce apple vinegar using Kefir grains.
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comparative study of the biochemical changes and volatile compound formations during the production of novel whey based Kefir beverages and traditional milk Kefir
Food Chemistry, 2011Co-Authors: Karina Teixeira Magalhaes, José M. Oliveira, Giuliano Dragone, Lucilia Domingues, Gilberto Vinicius De Melo Pereira, José A. Teixeira, Joao Almeida B E Silva, Rosane Freitas SchwanAbstract:Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of Kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by Kefir grains and compared with values obtained during the production of traditional milk Kefir. The results showed that Kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8-8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based Kefir and milk Kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of Kefir-like beverages similar to milk Kefir.
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brazilian Kefir structure microbial communities and chemical composition
Brazilian Journal of Microbiology, 2011Co-Authors: Karina Teixeira Magalhaes, Giuliano Dragone, Gilberto Vinicius De Melo Pereira, Cassia Roberta Campos, Rosane Freitas SchwanAbstract:Microbial ecology and chemical composition of Brazilian Kefir beverage was performed. The microorganisms associated with Brazilian Kefir were investigated using a combination of phenotypic and genotypic methods. A total of 359 microbial isolates were identified. Lactic acid bacteria (60.5%) were the major isolated group identified, followed by yeasts (30.6%) and acetic acid bacteria (8.9%). Lactobacillus paracasei (89 isolates), Lactobacillus parabuchneri (41 isolates), Lactobacillus casei (32 isolates), Lactobacillus Kefiri (31 isolates), Lactococcus lactis (24 isolates), Acetobacter lovaniensis (32 isolates), Kluyveromyces lactis (31 isolates), Kazachstania aerobia (23 isolates), Saccharomyces cerevisiae (41 isolates) and Lachancea meyersii (15 isolates) were the microbial species isolated. Scanning electron microscopy showed that the microbiota was dominated by bacilli (short and curved long) cells growing in close association with lemon-shaped yeasts cells. During the 24 h of fermentation, the protein content increased, while lactose and fat content decreased. The concentration of lactic acid ranged from 1.4 to 17.4 mg/ml, and that of acetic acid increased from 2.1 to 2.73 mg/ml. The production of ethanol was limited, reaching a final mean value of 0.5 mg/ml.
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Comparative study of the biochemical changes and volatile compound formations during the production of novel whey-based Kefir beverages and traditional milk Kefir
Food Chemistry, 2011Co-Authors: Karina Teixeira Magalhaes, João B.almeida E Silva, José M. Oliveira, Giuliano Dragone, Lucilia Domingues, Gilberto Vinicius De Melo Pereira, José A. Teixeira, Rosane Freitas SchwanAbstract:Cheese whey (CW) and deproteinised cheese whey (DCW) were investigated for their suitability as novel substrates for the production of Kefir-like beverages. Lactose consumption, ethanol production, as well as organic acids and volatile compounds formation, were determined during CW and DCW fermentation by Kefir grains and compared with values obtained during the production of traditional milk Kefir. The results showed that Kefir grains were able to utilise lactose from CW and DCW and produce similar amounts of ethanol (7.8-8.3 g/l), lactic acid (5.0 g/l) and acetic acid (0.7 g/l) to those obtained during milk fermentation. In addition, the concentration of higher alcohols (2-methyl-1-butanol, 3-methyl-1-butanol, 1-hexanol, 2-methyl-1-propanol, and 1-propanol), ester (ethyl acetate) and aldehyde (acetaldehyde) in cheese whey-based Kefir and milk Kefir beverages were also produced in similar amounts. Cheese whey and deproteinised cheese whey may therefore serve as substrates for the production of Kefir-like beverages similar to milk Kefir. © 2010 Elsevier Ltd. All rights reserved.
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diversity of bacteria present in milk Kefir grains using culture dependent and culture independent methods
Food Research International, 2010Co-Authors: Maria Gabriela Da Cruz Pedrozo Miguel, Patricia Gomes Cardoso, Lilian De Assis Lago, Rosane Freitas SchwanAbstract:In the present work bacteria associated with milk Kefir grains from several Brazilian States, Canada and the United States of America under traditional conditions have, for the first time, been studied using a combination of pheno-and genotypic methods. Conventional culturing was performed and a total of 270 isolates were obtained from all samples. Isolates were identified using biochemical tests and partial sequence analysis of 16S rDNA. Denaturing gradient gel electrophoresis (DGGE) of partially amplified 16S rDNA followed by sequencing of the most intense bands showed that the dominant bacterium was Lactobacillus Kefiri. PCR-DGGE revealed the presence of Gluconobacter japonicus and Lactobacillus uvarum which were no isolated. Conventional isolation revealed the presence of L. helveticus, L. Kefiri and Acetobacter syzygii not identified among the sequenced DGGE bands. This study is the first to report the presence of Lactobacillus satsumensis and Acetobacter syzygii in milk Kefir grains.
Luc De Vuyst - One of the best experts on this subject based on the ideXlab platform.
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The water Kefir grain inoculum determines the characteristics of the resulting water Kefir fermentation process.
Journal of Applied Microbiology, 2017Co-Authors: David Laureys, Luc De VuystAbstract:Aims To investigate the influence of the water Kefir grain inoculum on the characteristics of the water Kefir fermentation process. Methods and results Three water Kefir fermentation processes were started with different water Kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile, and metabolite production course. The inoculum determined the water Kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations, and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these microorganisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii, and Saccharomyces cerevisiae were always present and may be the key microorganisms during water Kefir fermentation. Low water Kefir grain growth was associated with small grains with high viable counts of microorganisms, fast fermentation, and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. Conclusions The water Kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key microorganisms was always present during fermentation. Significance and Impact of the Study This study allows a rational selection of a water Kefir grain inoculum. This article is protected by copyright. All rights reserved.
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Investigation of the instability and low water Kefir grain growth during an industrial water Kefir fermentation process
Applied Microbiology and Biotechnology, 2017Co-Authors: David Laureys, Amandine Van Jean, Jean Dumont, Luc De VuystAbstract:A poorly performing industrial water Kefir production process consisting of a first fermentation process, a rest period at low temperature, and a second fermentation process was characterized to elucidate the causes of its low water Kefir grain growth and instability. The frozen-stored water Kefir grain inoculum was thawed and reactivated during three consecutive prefermentations before the water Kefir production process was started. Freezing and thawing damaged the water Kefir grains irreversibly, as their structure did not restore during the prefermentations nor the production process. The viable counts of the lactic acid bacteria and yeasts on the water Kefir grains and in the liquors were as expected, whereas those of the acetic acid bacteria were high, due to the aerobic fermentation conditions. Nevertheless, the fermentations progressed slowly, which was caused by excessive substrate concentrations resulting in a high osmotic stress. Lactobacillus nagelii, Lactobacillus paracasei, Lactobacillus hilgardii, Leuconostoc mesenteroides, Bifidobacterium aquiKefiri, Gluconobacter roseus/oxydans, Gluconobacter cerinus, Saccharomyces cerevisiae, and Zygotorulaspora florentina were the most prevalent microorganisms. Lb. hilgardii, the microorganism thought to be responsible for water Kefir grain growth, was not found culture-dependently, which could explain the low water Kefir grain growth of this industrial process.
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Microbial species diversity, community dynamics, and metabolite kinetics of water Kefir fermentation
Applied and Environmental Microbiology, 2014Co-Authors: David Laureys, Luc De VuystAbstract:Water Kefir is a sour, alcoholic, and fruity fermented beverage of which the fermentation is started with water Kefir grains. These water Kefir grains consist of polysaccharide and contain the microorganisms responsible for the water Kefir fermentation. In this work, a water Kefir fermentation process was followed as a function of time during 192 h to unravel the community dynamics, the species diversity, and the kinetics of substrate consumption and metabolite production. The majority of the water Kefir ecosystem was found to be present on the water Kefir grains. The most important microbial species present were Lactobacillus casei/paracasei, Lactobacillus harbinensis, Lactobacillus hilgardii, Bifidobacterium psychraerophilum/crudilactis, Saccharomyces cerevisiae, and Dekkera bruxellensis. The microbial species diversities in the water Kefir liquor and on the water Kefir grains were similar and remained stable during the whole fermentation process. The major substrate, sucrose, was completely converted after 24 h of fermentation, which coincided with the production of the major part of the water Kefir grain polysaccharide. The main metabolites of the fermentation were ethanol and lactic acid. Glycerol, acetic acid, and mannitol were produced in low concentrations. The major part of these metabolites was produced during the first 72 h of fermentation, during which the pH decreased from 4.26 to 3.45. The most prevalent volatile aroma compounds were ethyl acetate, isoamyl acetate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate, which might be of significance with respect to the aroma of the end product.
Rudi F Vogel - One of the best experts on this subject based on the ideXlab platform.
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structural characterization of the exopolysaccharides from water Kefir
Carbohydrate Polymers, 2018Co-Authors: Lea Fels, Rudi F Vogel, Frank Jakob, Daniel WefersAbstract:Abstract Water Kefir is a beverage which is produced by initiating fermentation of a fruit extract/sucrose solution with insoluble Kefir grains. Exopolysaccharides that are formed from sucrose play a major role in the Kefir grain formation, but the exopolysaccharides in the Kefir beverage and the detailed structural composition of the whole Kefir grains have not been studied yet. Therefore, Kefir grains and the corresponding Kefir beverage were analyzed for exopolysaccharides by multiple chromatographic approaches and two-dimensional NMR spectroscopy. Furthermore, different fractionation techniques were applied to obtain further information about the exopolysaccharides. The exopolysaccharide-fraction of the investigated Kefir beverage was predominantly composed of O3- and O2-branched dextrans as well as lower amounts of levans. The insoluble dextrans from the Kefir grains were mostly O3-branched and contained an elevated portion of 1,3-linked glucose units compared to the soluble dextrans. The structurally different exopolysaccharides in water Kefir suggest the involvement of multiple bacteria.
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comparative phylobiomic analysis of the bacterial community of water Kefir by 16s rrna gene amplicon sequencing and ardra analysis
Journal of Applied Microbiology, 2013Co-Authors: Anna Gulitz, Jasmin Stadie, Matthias A Ehrmann, Wolfgang Ludwig, Rudi F VogelAbstract:AIMS: The aim of this study was to analyse the bacterial microbiota of water Kefir using culture-independent methods. METHODS AND RESULTS: We compared four water Kefirs of different origins using 16S rDNA amplicon sequencing and ARDRA. The microbiota consisted of different proportions of the genera Lactobacillus (Lact.), Leuconostoc (Leuc.), Acetobacter (Acet.) and Gluconobacter. Surprisingly, varying but consistently high numbers of sequences representing members of the genus Bifidobacterium (Bif.) were found in all Kefirs. Whereas part of the bifidobacterial sequences could be assigned to Bifidobacterium psychraerophilum, a majority of sequences identical to each other could not be assigned to any known species. A nearly full-length sequence of the latter exhibited a beyond-species similarity (96.4%) with the sequence from the closest relative species Bif. psychraerophilum. A Bifidobacterium-specific ARDRA analysis reflected the abundance of the novel Bifidobacterium species by revealing its unique MboI restriction profile. Attempts to isolate the bifidobacteria were successful for Bif. psychraerophilum only. CONCLUSIONS: The complexity of the water Kefir microbiota has been underestimated in previously studies. The occurrence of bifidobacteria as part of the consortium is novel. SIGNIFICANCE AND IMPACT OF THE STUDY: These data give new insights into the understanding of the complexity of food fermentations and underline the need for approaches detecting noncultivable organisms.
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the microbial diversity of water Kefir
International Journal of Food Microbiology, 2011Co-Authors: Anna Gulitz, Jasmin Stadie, Mareike Wenning, Matthias A Ehrmann, Rudi F VogelAbstract:Abstract The microbial diversity of water Kefir, made from a mixture of water, dried figs, a slice of lemon and sucrose was studied. The microbial consortia residing in the granules of three water Kefirs of different origins were analyzed. A collection of 453 bacterial isolates was obtained on different selective/differential media. Bacterial isolates were grouped with randomly amplified polymorphic DNA (RAPD)-PCR analyses. One representative of each RAPD genotype was identified by comparative 16S rDNA gene sequencing. The predominant genus in water Kefirs I and II was Lactobacillus , which accounted for 82.1% in water Kefir I and 72.1% in water Kefir II of the bacterial isolates. The most abundant species in water Kefirs I and II were Lactobacillus hordei and Lb. nagelii followed by considerably lower numbers of Lb. casei . Other lactic acid bacteria (LAB) were identified as Leuconostoc mesenteroides and Lc. citreum in all three water Kefirs. The most abundant species in water Kefir III was Lc. mesenteroides (28%) and Lc. citreum (24.3%). A total of 57 LAB belonging to the species of Lb. casei , Lb. hordei , Lb. nagelii , Lb. hilgardii and Lc. mesenteroides were able to produce exopolysacchrides from sucrose. Non LABs were identified as Acetobacter fabarum and Ac. orientalis . The Acetobacter species were more prevalent in consortium III. Cluster analyses of RAPD-PCR patterns revealed an interspecies diversity among the Lactobacillus and Acetobacter strains. Aditionally, Saccharomyces cerevisiae , Lachancea fermentati , Hanseniaospora valbyensis and Zygotorulaspora florentina were isolated and identified by comparison of partial 26S rDNA sequences and FTIR spectroscopy.
David Laureys - One of the best experts on this subject based on the ideXlab platform.
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The water Kefir grain inoculum determines the characteristics of the resulting water Kefir fermentation process.
Journal of Applied Microbiology, 2017Co-Authors: David Laureys, Luc De VuystAbstract:Aims To investigate the influence of the water Kefir grain inoculum on the characteristics of the water Kefir fermentation process. Methods and results Three water Kefir fermentation processes were started with different water Kefir grain inocula and followed as a function of time regarding microbial species diversity, community dynamics, substrate consumption profile, and metabolite production course. The inoculum determined the water Kefir grain growth, the viable counts on the grains, the time until total carbohydrate exhaustion, the final metabolite concentrations, and the microbial species diversity. There were always 2-10 lactic acid bacterial cells for every yeast cell and the majority of these microorganisms was always present on the grains. Lactobacillus paracasei, Lactobacillus hilgardii, Lactobacillus nagelii, and Saccharomyces cerevisiae were always present and may be the key microorganisms during water Kefir fermentation. Low water Kefir grain growth was associated with small grains with high viable counts of microorganisms, fast fermentation, and low pH values, and was not caused by the absence of exopolysaccharide-producing lactic acid bacteria. Conclusions The water Kefir grain inoculum influences the microbial species diversity and characteristics of the fermentation process. A select group of key microorganisms was always present during fermentation. Significance and Impact of the Study This study allows a rational selection of a water Kefir grain inoculum. This article is protected by copyright. All rights reserved.
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Investigation of the instability and low water Kefir grain growth during an industrial water Kefir fermentation process
Applied Microbiology and Biotechnology, 2017Co-Authors: David Laureys, Amandine Van Jean, Jean Dumont, Luc De VuystAbstract:A poorly performing industrial water Kefir production process consisting of a first fermentation process, a rest period at low temperature, and a second fermentation process was characterized to elucidate the causes of its low water Kefir grain growth and instability. The frozen-stored water Kefir grain inoculum was thawed and reactivated during three consecutive prefermentations before the water Kefir production process was started. Freezing and thawing damaged the water Kefir grains irreversibly, as their structure did not restore during the prefermentations nor the production process. The viable counts of the lactic acid bacteria and yeasts on the water Kefir grains and in the liquors were as expected, whereas those of the acetic acid bacteria were high, due to the aerobic fermentation conditions. Nevertheless, the fermentations progressed slowly, which was caused by excessive substrate concentrations resulting in a high osmotic stress. Lactobacillus nagelii, Lactobacillus paracasei, Lactobacillus hilgardii, Leuconostoc mesenteroides, Bifidobacterium aquiKefiri, Gluconobacter roseus/oxydans, Gluconobacter cerinus, Saccharomyces cerevisiae, and Zygotorulaspora florentina were the most prevalent microorganisms. Lb. hilgardii, the microorganism thought to be responsible for water Kefir grain growth, was not found culture-dependently, which could explain the low water Kefir grain growth of this industrial process.
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Microbial species diversity, community dynamics, and metabolite kinetics of water Kefir fermentation
Applied and Environmental Microbiology, 2014Co-Authors: David Laureys, Luc De VuystAbstract:Water Kefir is a sour, alcoholic, and fruity fermented beverage of which the fermentation is started with water Kefir grains. These water Kefir grains consist of polysaccharide and contain the microorganisms responsible for the water Kefir fermentation. In this work, a water Kefir fermentation process was followed as a function of time during 192 h to unravel the community dynamics, the species diversity, and the kinetics of substrate consumption and metabolite production. The majority of the water Kefir ecosystem was found to be present on the water Kefir grains. The most important microbial species present were Lactobacillus casei/paracasei, Lactobacillus harbinensis, Lactobacillus hilgardii, Bifidobacterium psychraerophilum/crudilactis, Saccharomyces cerevisiae, and Dekkera bruxellensis. The microbial species diversities in the water Kefir liquor and on the water Kefir grains were similar and remained stable during the whole fermentation process. The major substrate, sucrose, was completely converted after 24 h of fermentation, which coincided with the production of the major part of the water Kefir grain polysaccharide. The main metabolites of the fermentation were ethanol and lactic acid. Glycerol, acetic acid, and mannitol were produced in low concentrations. The major part of these metabolites was produced during the first 72 h of fermentation, during which the pH decreased from 4.26 to 3.45. The most prevalent volatile aroma compounds were ethyl acetate, isoamyl acetate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate, which might be of significance with respect to the aroma of the end product.
Zeynep B. Guzel-seydim - One of the best experts on this subject based on the ideXlab platform.
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The effect of Kefir produced from natural Kefir grains on the intestinal microbial populations and antioxidant capacities of Balb/c mice
Food Research International, 2018Co-Authors: Fatih Selim Erdogan, Seda Ozarslan, Zeynep B. Guzel-seydimAbstract:Abstract Kefir is a probiotic and fermented dairy product authentically produced from Kefir grains. Kefir grain, as a natural starter culture, contains numerous lactic acid bacteria, acetic acid bacteria and yeasts within a polysaccharide structure. True Kefir is a miraculous food in terms of its favorable contributions to human health. However, Kefir starter cultures used in industrial Kefir productions contain very few lactic acid bacteria and yeasts. These starter cultures do not contain characteristic Kefir bacteria, such as Lactobacillus Kefiranofaciens, Lactobacillus Kefiri, and Lactobacillus paraKefiri. The objective of this study was to compare the intestinal microorganisms of BALB/c mice fed Kefir produced from natural Kefir grains and Kefir produced from starter culture. The mice in Kefir groups were fed an oral dose of 0.3 mL Kefir/day for 15 days, and the control group did not receive Kefir. The feces were collected in metabolic cages, and the lactic acid bacteria, yeasts-fungi, and Lactobacillus acidophilus and Bifidobacterium species were determined. Additionally, PCR analysis based on yeast-fungus 23S rRNA was carried out, and serial analysis was performed with an ABI 3100 Genetic Analyzer. Serum total antioxidant status (TAS), serum total oxidant status (TOS) levels, malondialdehyde (MDA) levels and myeloperoxidase (MPO) levels were determined. The mean lactic acid bacteria (LAB) contents of the feces samples obtained from the mice fed Kefir samples produced from Kefir grains and starter culture were 9.08 log cfu/g and 7.32 log cfu/g on the 15th day, respectively. Mold was found in both the starter Kefir group and in the control group (range, 1.91–2.02 log cfu/g). The mold was identified as Trichoderma koningii, a potential human pathogen and carcinogen. It was very impressive that mold was not observed in the feces samples of the mice fed the Kefir produced from Kefir grains. The highest TAS value was determined in the serum samples of mice fed Kefir produced using Kefir grains. MPO values in the small intestines of mice fed Kefir produced using starter culture were higher than those in the CK group that was associated with possible inflammation. This study might lead to new studies focused on the antifungal effects of Kefir and on the importance of using Kefir grains in the production of Kefir.
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Immunological effects of Kefir produced from Kefir grains versus starter cultures when fed to mice
Functional Foods in Health and Disease, 2018Co-Authors: Funda Davras, Zeynep B. Guzel-seydimAbstract:Background: Natural Kefir grains have a unique microbiota. The structure contains lactic acid bacteria (LAB), acetic acid bacteria and yeast in specific ratios in a polysaccharide matrix. Authentic Kefir is produced by a traditional method using Kefir grains cultured in milk. In contrast, starter cultures are used instead of Kefir grains in the industry. The commercial Kefir starter cultures used are limited and often very different from the Kefir grain microbiota. The resultant commercial “Kefir” is just a fermented drink containing some probiotic microorganisms and does not possess the same microbial population or chemical and physical characteristics of authentic Kefir. The aim of this project was to determine and compare the effects on the mouse immune system of Kefir produced using natural Kefir grain versus commercial Kefir produced by starter culture. Methods: Kefir produced with different cultures was fed to Balb/c mice (6-8 weeks, 20-25 grams, male) by gavage for two weeks at 300 μl/day. Intestinal tissues were collected from sacrificed mice at the end of the trial. The control group of mice (CNI group) were fed with phosphate buffered saline (PBS). The experimental treatments were mice fed mice fed authentic Kefir produced using Kefir grains (KGI group) and mice fed Kefir produced using starter culture (STI group). Immunoglobulin (Ig) A, Immunoglubulin G, Interleukin (IL)-4, Interleukin-10, Interleukin-12, Toll Like Receptor (TLR)-4 were analyzed immunologically in intestinal fluid samples. Results: Results indicated that IgA values were 60.87, 72.78 and 55.31 ng/mL; IgG values were 26.59, 38.90 and 29.44 ng/mL; IL-4 values were 84, 40.28 and 53.28 pg/mL; IL-10 values were 110.98, 175.91 and 134.77 pg/mL; IL-12 values were 53.90, 22.93 and 24.75 pg/mL; TLR-4 values were 0.53, 0.43 and 1.37 ng/mL, for the CNI, KGI and STI groups, respectively. Conclusion: The high probiotic content of grain Kefir had the ability to modulate many immunological mechanisms. Keywords: immune system, in vivo , Kefir grain, probiotic, starter Kefir culture
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Effect of Gluconacetobacter spp. on Kefir grains and Kefir quality
Food Science and Biotechnology, 2015Co-Authors: Nilgün Özdemir, Zeynep B. Guzel-seydimAbstract:Microbial, chemical, physical, and sensorial analyses of Kefir samples produced using Kefir grains embedded with Gluconacetobacter spp. were investigated using Kefir samples with Gluconacetobacter spp. inclusion (KA), and regular Kefir grains (control, KC) lacking Gluconacetobacter spp. The genus Gluconacetobacter, (identified using PCR) isolated from apple cider vinegar, was embedded in Kefir grains. Inclusion of Gluconacetobacter spp. provided a significant biomass increase (p
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Influence of Kefir fermentation on the bioactive substances ofdifferent breed goat milks
LWT - Food Science and Technology, 2015Co-Authors: Gulcin Satir, Zeynep B. Guzel-seydimAbstract:The aim of this study was to investigate the effects of Kefir fermentation on the functional properties of Hair and Saanen goat milk samples, including intensive and extensive nutritional regimes. Kefir samples were produced with natural Kefir grains (2%). Microbial content, the total phenolic content, total antioxidant activity (using ORAC and TEAC assays) and quantification of phenolic substances using liquid chromatography were carried out.After fermentation with Kefir grains, the antioxidant activity of the Kefir samples increased. Kefir made from goat milk had higher content of microflora and total antioxidant activity. The total phenolic contents of the Kefir samples made from different goat milk samples ranged between 726.08 and 1359.32mg of gallic acid equivalents (GAE) L-1. The phenolic compounds in Kefir samples ranged between 0.77 and 4.21mg 100g-1 for gallic acid and 0.36-5.09mg 100g-1 for catechin. This study showed that goat Kefir samples had significantly high bioactive substances.
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Effects of different fermentation parameters on quality characteristics of Kefir.
Journal of dairy science, 2013Co-Authors: Tuğba Kök-taş, Atif Can Seydim, Barbaros Ozer, Zeynep B. Guzel-seydimAbstract:The main objective of the study was to determine the effects of different fermentation parameters on Kefir quality. Kefir samples were produced using Kefir grains or natural Kefir starter culture, and fermentation was carried out under normal or modified atmosphere (10% CO(2)) conditions. The microbiological (lactobacilli, lactococci, Lactobacillus acidophilus, Bifidobacterium spp., and yeasts), chemical (pH, lactic acid, total solids, protein, ethanol, exopolysaccharide contents), rheological, and sensory properties of Kefir samples were investigated during a 21-d storage period. The use of different fermentation parameters or the choice of grain versus natural Kefir starter culture did not significantly affect the content of microorganisms. Lactobacilli, lactococci, and yeast contents of Kefir samples varied between 9.21 and 9.28, 9.23 and 9.29, and 4.71 and 5.53 log cfu/mL, respectively, on d 1 of storage. Contents of L. acidophilus and Bifidobacterium spp. were between 5.78 and 6.43 and between 3.19 and 6.14 log cfu/mL, respectively, during 21 d of storage. During the storage period, pH, lactic acid (%), total solids (%), protein (%), acetaldehyde, and ethanol contents of Kefir samples ranged from 4.29 to 4.53, from 0.81 to 0.95%, from 7.81 to 8.21%, from 3.09 to 3.48%, from 3.8 to 23.6 mg/L, and from 76.5 to 5,147 mg/L, respectively. The exopolysaccharide contents of the samples decreased during 21 d of cold storage; the samples fermented under modified atmosphere had relatively higher exopolysaccharide contents, indicating higher potential therapeutic properties. The Kefir samples exhibited non-Newtonian pseudoplastic flow behavior according to the power law model. According to the sensory results, Kefir produced from natural Kefir starter culture under CO(2) atmosphere had the highest overall evaluation score at d 1.