Microbiological and Chemical characterization of water kefir: An innovative source of potential probiotics for bee nutrition / Caracterización microbiológica y química del kéfir de agua: una fuente innovadora de potenciales probióticos para la nutrición de las abejas

Abstract We evaluated the microbial composition of water kefir grains and beverage overthe course of one year to determine whether the number and type of microorganisms changedover the time. Bacteria and yeast colonies with different morphologies were isolated fromwater kefir and their antimicrobial activity was evaluated against Paenibacillus larvae andAscosphaera apis. A chemical characterization of kefir was also carried out. Our results con-firmed that bacteria and yeasts were more numerous in kefir grains compared with those in thebeverage. The counts of microorganisms declined, although an important microbial community was still present in kefir after the long storage period. Eleven strains which inhibited bee pathogens were isolated from kefir. Genotypic results demonstrated that these isolates included Lentilactobacillus hilgardii, Lentilactobacillus buchneri and Saccharomyces cerevisiae. Thus, water kefir may be an innovative source of potential probiotic strains for bee nutrition in order to control honeybee diseases.

Resumen Evaluamos la composición microbiana del kéfir de agua durante un ano para determinar si la cantidad y el tipo de microorganismos cambiaban con el tiempo. Se aislaron colonias de bacterias y de levaduras con diferentes morfologías, y su actividad antimicrobiana se evaluó frente a Paenibacillus larvaey Ascosphaeraapis. También se realizó una caracterización química del kéfir. Nuestros resultados confirmaron que las bacterias y las levaduras eran más numerosas en los gránulos de kéfir en comparación con la parte líquida. Los recuentos de microorganismos disminuyeron, aunque una cantidad igualmente importante se encontró en el kéfir después de un año. Se aislaron del kéfir once cepas que inhibieron los mencionados patógenos de abejas. Los resultados genotípicos demostraron que estos aislamientos eran Lentilactobacillus hilgardii, Lentilactobacillus buchneri y Saccharomyces cerevisiae. Por lo tanto, el kéfir de agua podría ser una fuente innovadora de potenciales cepas probióticas para contribuir a la nutrición y sanidad de las abejas.

Effect of kefir on increased apoptosis in liver and kidney in cisplatin toxicity / Efecto del kéfir sobre el aumento de la apoptosis en el hígado y los riñones en la toxicidad del cisplatino

SUMMARY: Cisplatin is a chemotherapeutic agent inducing liver and kidney damage. In this study, we intended to investigate the impact of kefir beverage, an essential probiotic and functional food, on liver and kidney damage induced by cisplatin. Wistar albino rats were divided into four groups: Control, Cisplatin (single dose of 7 mg/kg, intraperitoneal), Kefir (2 ml/d, 7 d, oral gavage), and Cisplatin+Kefir (CK). At the end of day 7, animals were euthanized. Blood, kidney, and liver tissue samples were collected. For both tissues, biochemically ALT, AST, Urea, Creatine; histomorphologically, hematoxylin-eosin, Masson's Trichrome, and immunohistochemical staining of caspase-3, a marker of apoptosis, were performed. Serum urea and creatinine levels of the Cisplatin group were significantly higher than the Control group (p<0.05). In the CK group, kefir consumption decreased urea and creatinin levels approached to Control and Kefir groups. Cisplatin resulted in higher ALT and AST activities, indicating hepatocellular damage, compared to the Control group (p<0.05). Kefir consumption decreased ALT activities approached to both the Control and Kefir group. Histomorphological observations were in agreement biochemical results. In liver and kidney tissues, structural damage was observed with an increase in collagen fibers in the Cisplatin group, and Caspase-3 activity was immunohistochemically higher than in the other groups. In the CK group, collagen fiber increase, structural damage, and Caspase-3 activities were less than in the Cisplatin group. Kefir consumption alleviated liver and kidney damage. However, more research is required to understand such effect of kefir better.

RESUMEN: El cisplatino es un agente quimioterapéutico que induce daño hepático y renal. En este estudio, intentamos investigar el efecto del kéfir, un alimento funcional y probiótico esencial, en el daño hepático y renal inducido por el cisplatino. Se dividieron ratas albinas Wistar en cuatro grupos: control, cisplatino (dosis única de 7 mg/kg, intraperitoneal), kéfir (2 ml/día, 7 días, sonda oral) y cisplatino + kéfir (CK). Al final del día 7, los animales fueron sacrificados. Se recolectaron muestras de sangre, riñón y tejido hepático. Se determinó ALT, AST, Urea y Creatina; Para el análisis histomorfológico, se realizaron tinciones con hematoxilina-eosina, tricrómico de Masson y para inmunohistoquímica, caspasa-3, un marcador de apoptosis. Los niveles séricos de urea y creatinina del grupo de cisplatino fueron significativamente más altos que los del grupo de control (p<0,05). En el grupo CK, el consumo de kéfir disminuyó los niveles de urea y creatinina acercándose a los grupos Control y Kéfir. El cisplatino resultó en actividades más altas de ALT y AST, lo que indica daño hepatocelular, en comparación con el grupo Control (p<0.05). El consumo de kéfir disminuyó las actividades de ALT tanto en el grupo Control como en el de Kéfir. Las observaciones histomorfológicas coincidieron con los resultados bioquímicos. En tejidos hepáticos y renales se observó daño estructural con aumento de fibras colágenas en el grupo de Cisplatino, y la actividad de Caspasa-3 fue inmunohistoquímicamente mayor que en los otros grupos. En el grupo de CK, el aumento de las fibras colágenas, el daño estructural y las actividades de Caspasa-3 fueron menores que en el grupo Cisplatino. El consumo de kéfir mejoró el daño hepático y renal. Sin embargo, se requiere más investigación para comprender mejor el efecto del kéfir.

The effect of kefir consumption on the lipid profile for individuals with normal and dyslipidemic properties: a randomized controlled trial / O efeito do consumo de kefir no perfil lipídico em indivíduos com propriedades normais e dislipidêmicas: um ensaio clínico randomizado

ABSTRACT Objective This research was conducted as a prospective, self-controlled, eight-week clinical trial to investigate the effect of kefir consumption on the lipid profile of individuals with normal and dyslipidemic properties. Methods Kefir microorganisms given to volunteer subjects were determined using classical microbial count methods and qReal-Time Polymerase Chain Reaction. The study was carried out with 23 volunteer hospital health personnel between the ages of 20 and 55 who met the research criteria and did not have any health problems. The volunteers regularly consumed kefir on an empty stomach for four weeks. In the last stage, the eight-week study was completed by making blood and anthropometric measurements of the subjects, who continued to be studied without kefir consumption for four more weeks. Results Considering the changes in the serum lipid profiles of 13 individuals with dyslipidemic symptoms during the 4-week period they consumed kefir, Total Cholesterol values decreased by 9.15% compared to initial values, LDL-Cholesterol values decreased by 10.64%, HDL-Cholesterol values decreased by 6.9%, and triglyceride values decreased by 2.46%. The changes in the serum lipid profiles of 13 individuals with dyslipidemic findings at the end of an eight-week study were a 5.71% decrease in total cholesterol values (p<0.018) considered statistically significant, as well as a 5.31% decrease in LDL-Cholesterol values (p<0.021); the HDL-Cholesterol results were found to be significant with an 8.58% decrease in the values (p<0.035) and insignificant with a 17.21% increase in the triglyceride values (p<0.926). We concluded that regular kefir consumption was effective in both women and men in lowering total cholesterol and LDL-Cholesterol from blood lipid profiles, especially in individuals with dyslipidemic symptoms, while this effect was not observed in normal individuals. Conclusion Kefir can positively affect the total cholesterol and LDL-Cholesterol blood parameters of dyslipidemic individuals with high serum lipid values.

RESUMO Objetivo Esta pesquisa foi conduzida como um ensaio clínico prospectivo e autocontrolado de oito semanas para investigar o efeito do consumo de kefir no perfil lipídico de indivíduos com propriedades normais e dislipidêmicas. Métodos Microrganismos kefir dados a voluntários foram determinados usando métodos clássicos de contagem microbiana e de reação em cadeia da polimerase em tempo real. O estudo foi conduzido em 23 profissionais de saúde de hospitais voluntários, com idades entre 20 e 55 anos, que atendiam aos critérios da pesquisa e não apresentavam problemas de saúde. Os voluntários consumiram kefir com o estômago vazio regularmente durante quatro semanas. No último estágio, o estudo de oito semanas foi concluído com medidas de sangue e antropométricas dos indivíduos, que continuaram a ser avaliados sem consumo de kefir por mais quatro semanas. Resultados Considerando as mudanças nos perfis lipídicos séricos de 13 indivíduos com sintomas dislipidêmicos durante o período de quatro semanas em que consumiram kefir, os valores de colesterol total diminuíram em 9,15% em comparação com os valores iniciais; os valores de LDL-Colesterol diminuíram em 10,64%, os valores de HDL-Colesterol diminuíram em 6,9% e os valores de triglicerídeos diminuíram em 2,46%. Ao final de um estudo de oito semanas, o resultado foi considerado estatisticamente significativo, com queda de 5,71% nos valores de colesterol total (p<0,018); de 5,31% nos valores de Colesterol-LDL (p<0,021) e de 8,58% nos valores de HDL-Colesterol (p <0,035), e insignificantes com aumento de 17,21% nos valores de triglicerídeos (p<0,926). Como resultado do estudo, concluiu-se que o consumo regular de kefir foi eficaz em mulheres e homens na redução do colesterol total e do LDL-Colesterol dos perfis de lipídios no sangue, especialmente em indivíduos com sintomas dislipidêmicos, enquanto esse efeito não foi observado em indivíduos normais. Conclusão O kefir pode afetar positivamente os parâmetros sanguíneos do colesterol total e do LDL-Colesterol de indivíduos dislipidêmicos com altos valores de lipídios séricos.

The effects of kefir in mixed meals on appetite and food intake: a randomized cross-over trial / Os efeitos do quefir em refeições mistas sobre o apetite e a ingestão de alimentos: um estudo randomizado cruzado

ABSTRACT Objective The natural probiotic kefir is fermented milk, and may have effects on satiety and voluntary energy intake. This randomized crossover trial aimed to determine whether kefir, consumed with low- or high-glycemic index meals, affects appetite and subsequent food intake. Methods Twenty four healthy females aged 21-24 years, were recruited from Erciyes University and the surrounding community. The participants were submitted to three different breakfasts: a low glycemic index accompanied by milk, a low glycemic index with kefir, and a high glycemic index with kefir, with a 1-week washout period between meals. At 0, 15, 30, 60, 90, 120, 150, and 180 minutes after the meal, appetite ratings were measured by the visual analog scale, and then ad libitum lunch was served. Results No differences in appetite scores and voluntary energy intake were detected between the test meals. Furthermore, palatability ratings were similar between test meals, except for the higher score of high glycemic index kefir for overall palatability. Conclusion This study demonstrated that adding kefir to a high glycemic index meal may prevent increases in appetite and food intake, resulting in postprandial responses similar to those of a low glycemic index meal. These findings might enable the development of novel dietary strategies based on appetite regulation to treat or prevent obesity, particularly for Western societies. This trial was registered at ClinicalTrials.gov under the process NCT03636217.

RESUMO Objetivo O quefir probiótico natural é um leite fermentado, e pode ter alguns efeitos sobre a saciedade e a ingestão voluntária de energia. Este ensaio cruzado randomizado teve como objetivo determinar se o quefir consumido com uma refeição de baixo ou alto índice glicêmico teria afetado o apetite e a ingestão de alimentos subsequente. Métodos Vinte e quatro mulheres saudáveis, com idades entre 21 e 24 anos, foram recrutadas na Universidade de Erciyes e na comunidade circundante. Todas as participantes foram submetidas a três cafés da manhã diferentes: um baixo índice glicêmico e leite, um baixo índice glicêmico e quefir, e um alto índice glicêmico e quefir, com um período de lavagem de 1 semana entre as refeições. Aos 0, 15, 30, 60, 90, 120, 150 e 180 minutos após a refeição, as classificações de apetite foram medidas por escala analógica visual e, em seguida, o almoço ad libitum foi servido. Resultados Não foram detectadas diferenças nos escores do apetite e na ingestão voluntária de energia entre as refeições do teste. Além disso, as classificações de palatabilidade foram semelhantes entre as refeições de teste, exceto o maior escore de alto índice glicêmico quefir para palatabilidade geral. Conclusão Este estudo demonstrou que a adição de quefir a uma refeição com alto teor de índice glicêmico pode impedir o aumento do apetite e da ingestão de alimentos, resultando em respostas pós-prandiais semelhantes a uma refeição com baixo teor de índice glicêmico. Esses achados poderiam permitir o desenvolvimento de novas estratégias dietéticas baseadas na regulação do apetite para tratar ou prevenir a obesidade, particularmente para a sociedade ocidental. Esse julgamento foi registado na ClinicalTrials.gov como NCT03636217.

Effect of fermented milk with kefir grains on the in vitro demineralization of bovine tooth enamel / Efecto de la leche fermentada con granos de kéfir sobre la desmineralización in vitro del esmalte dental bovino

The dental caries is a progressive destruction of the teeth tissue due to the disbalance in the normal molecule interactions between the enamel and the bio!lm, which alters the demineralization-remineralization process. Milk fermentation produces caseinphosphopeptides with proved remineralizing capacity of the enamel. The presence of these peptides in fermented milk with ke!r grains has been described. The purpose of this work was to evaluate in vitro the capacity of milk ke!r to prevent the demineralization of dental enamel. Bovine incisors (n=68, 17 per group) were treated for 72 h with different solutions: I: artificial saliva at pH 7.2 , II: demineralizing solution at pH 4.5, III: supernatant of kefir fermented milk at pH 4.5, IV: milk supernatant at pH 4.5. The effects of treatments were evaluated by the change in the weight of the specimens, calcium concentration in the solution and by scanning electron microscopy (SEM) of the enamel. Kefir milk supernatant prevented the demineralization process, that was evidenced by a change in weight and calcium concentration that were not different from group I, although the pH was 4.5. In contrast, group IV showed a decrease in weight and an increase in calcium concentration, compared with group I (one way ANOVA, p<0.05). Images of SEM agree with the values of weight and calcium concentration. These results indicate that kefir milk supernatant has a protective effect on enamel demineralization in vitro. (AU)

La caries dental es una patología debido a un desequilibrio en las interacciones moleculares normales entre el esmalte y la biopelícula, que altera el proceso de desmineralización remineralización. La fermentación de la leche produce fosfopéptidos de caseína con probada capacidad remineralizante del esmalte, y se ha descripto la presencia de estos péptidos en la leche fermentada con granos de kéfir. El propósito de este trabajo fue evaluar in vitro la capacidad del kéfir de leche para prevenir la desmineralización del esmalte dental. Sesenta y ocho incisivos bovinos (17 por grupo) fueron tratados durante 72 h con diferentes soluciones: I: saliva artificial, pH 7.2, II: solución desmineralizante, pH 4.5, III: sobrenadante de leche fermentada con kefir, pH 4.5, IV: sobrenadante de leche, pH 4.5. El proceso de desmineralización se evaluó mediante el cambio en el peso de las muestras, la concentración de calcio en la solución y microscopía electrónica de barrido (SEM) del esmalte. El sobrenadante de leche fermentada con kéfir impidió el proceso de desmineralización, que se evidenció por un cambio en el peso y la concentración de calcio que no discreparon del grupo I, a pesar de haber tenido un pH de 4.5. En contraste, el grupo IV mostró una disminución en el peso y un aumento en la concentración de calcio, en comparación con el grupo I (ANOVA a un criterio, p<0.05). Las imágenes SEM concuerdan con los cambios en el peso y la concentración de calcio en los grupos estudiados. Los datos obtenidos demuestran que el sobrenadante de la leche tratada con kéfir tiene un efecto protector sobre la desmineralización del esmalte in vitro, inducida por el pH ácido. (AU)

Elaboracâo e análise físico-química do kefir natural e adicionado de mel de abelha (Apis melífera) / Production and physicochemical analysis of natural kefir and added with honey (Apis melífera)

Kefir é um leite fermentado, com propriedades terapêuticas e probióticas. Desta forma, objetivou-se elaborar e avaliar a composição físico-química do kefir natural e adicionado de mel de abelha. Para a elaboração do kefir foram utilizados leite UHT e grãos de kefir. Em seguida, foi realizada a mistura do kefir e do mel. Foram testadas quatro concentrações de mel na bebida kefir (F1: 5%; F2: 10%; F3: 15% e F4: 20%). Posteriormente, o produto foi embalado e armazenado a 4 ºC. Foram realizadas análises físico-químicas de pH, acidez, cinzas, umidade e atividade de água conforme as normas do Instituto Adolfo Lutz. Os dados foram submetidos à ANOVA e teste Tukey. O presente estudo demonstrou as diferentes concentrações de mel de abelhas adicionadas na bebida kefir influenciaram nas características físico-químicas, exceto para as cinzas.

Desenvolvimento de sorvete de kefir com polpa de manga: avaliação sensorial, físico-química e de bactérias ácido láticas / Development of kefir ice cream with mango pulp: sensory evaluation, physico-chemistry and lactic acid bacteria

O kefir é uma bebida probiótica que contribui com benefícios à saúde. A sua utilização em preparações como o sorvete contribui para incorporação de micro-organismos probióticos na formulação podendo estimular seu consumo com objetivo funcional, por meio de uma sobremesa apreciada entre os consumidores. O trabalho objetivou analisar as características sensoriais, físico-químicas e microbiológicas de sorvetes caseiros desenvolvidos com kefir e polpa de manga. A formulação 1 do sorvete foi elaborada com kefir à 5% e a formulação 2 com kefir a 10% (m/v) e avaliadas quanto a aceitação, pH, acidez titulável e contagem de BAL. As análises microbiológicas foram realizadas no leite integral, kefir à 5% e 10 % m/v e nos sorvetes antes do congelamento (T0), após o congelamento final (T29 h) e após uma semana do congelamento (T168 h). O pH do kefir a 5 % diferiu (p < 0,05) daquele encontrado no de 10%. A análise sensorial mostrou que as formulações foram bem aceitas (p > 0,05) em todos os atributos. Após T168 h os sorvetes apresentaram contagem BAL igual a 2,7 x107 para a formulação 1 e 1,1 x108 UFC/mL para a formulação 2. Conclui-se que o kefir apresentou características de um leite fermentado e que o sorvete de kefir com polpa de manga à 5% e 10% apresentaram após T168 h contagem mínima de bactérias ácido lácticas prevista na legislação (AU)

Kefir is a probiotic drink that contributes health benefits. Its use in preparations such as ice cream can stimulate its consumption through a dessert appreciated among consumers, in addition to allowing the ingestion of lactic acid bacteria. The objective of this work was to analyze the sensorial, physicalchemistry and microbiological characteristics of homemade ice creams developed with kefir and mango pulp. Formulation 1 of the ice cream was made with kefir at 5% and formulation 2 with kefir at 10%, (w/v) and was evaluated for acceptance, pH, titratable acidity and lactic acid bacteria count. Microbiological analyzes were performed in whole milk, kefir at 5% and 10%, and in ice cream before freezing (T0), after the final freezing (T29 h) and after one week of freezing (T168 h). The pH of the kefir at 5% differed (p <0.05) from that found in 10%. Sensory analysis showed that the formulations were accepted (P> 0.05) in all attributes. After T168 h, the ice creams had a lactic acid bacteria count (AU)

Biochemical and microbiological changes during fermentation and storage of a fermented milk product prepared with Tibetan Kefir Starter

The aim of this study was to determine the optimal temperature ranges of milk fermentation by the microbial association Tibetan Kefir Grains and to set changes during the storage of the fermented milk product. The optimum technological parameters of milk fermentation by Tibetan Kefir Grains compliance are set. Compliance of these parameters ensures the desired metabolic processes and obtaining a dairy product with good organoleptic properties: fermentation temperature is 28±1 °Ð¡ for 24 hours, acidity of the product is from 80 to 120 % lactic acid, the amount of lactic acid bacteria ­ (2.9±0.22) × 108 CFU/cm3, fungi ­ (3.7±0.27) × 104 CFU/cm3. It was found that during the storage of the fermented milk drink produced on the leaven Tibetan Kefir Grains at the temperature of 4 ± 1 °Ð¡ for 10 days titratable acidity of the product increased by 1.2 times to 108.4 ± 8.3 °Ð¢, the population of lactic acid bacteria (Lactobacillus fermentum and some other) and yeast (Saccharomyces spp and some other) remained at the initial level. This indicates that the finished fermented milk product can be stored without losing functional probiotic properties for at least 10 days and meets the requirements of the standard (ISO 4471). At the same time, at a temperature of +8 ± 1°Ð¡ the expiration date of the fermented milk drink is decreases to 7 days(AU)

El objetivo de este estudio fue determinar los rangos de tempera- tura óptimos de la fermentación de la leche mediante la asociación microbiana de granos de Kéfir Tibetanos y estudiar los cambios durante el almacenamiento del producto lácteo fermentado. Se es- tablecieron los parámetros tecnológicos óptimos de fermentación de la leche utilizando los granos de Kéfir Tibetano. El cumplimien- to de estos parámetros garantiza los procesos metabólicos desea- dos y la obtención de un producto lácteo con buenas propiedades organolépticas: la temperatura de fermentación es de 28 ± 1° С durante 24 horas, la acidez del producto es de 80 a 120% de ácido láctico, la cantidad de bacterias del ácido láctico - (2.9 ± 0.22) × 108 UFC /cm3, hongos - (3.7 ± 0.27) × 104 UFC /cm3. Se encontró que durante el almacenamiento de la bebida láctea fermentada pro- ducida con los granos de Kéfir Tibetanos de levadura a una tempe- ratura de 4 ± 1° С durante 10 días, la acidez titulable del producto aumentó 1.2 veces a 108.4 ± 8.3 ° Т, la población de las bacterias del ácido láctico (Lactobacillus fermentum y algunas otras) y la levadura (Saccharomyces spp y otras) se mantuvieron en el nivel inicial. Esto indica que el producto lácteo fermentado terminado se puede almacenar sin perder propiedades probióticas funcionales durante al menos 10 días y cumple con los requisitos de la norma ISO 4417. Al mismo tiempo, a una temperatura de + 8 ± 1 ° С, la fecha de vencimiento de la bebida de leche fermentada se reduce a 7 días(AU)

Chemical composition and hypocholesterolemic effect of milk kefir and water kefir in Wistar rats / Composição química e efeito hipocolesterolêmico do kefir de leite e do kefir de água em ratos Wistar

ABSTRACT Objective To compare the effects of fermented kefir on the nutritional, physiological, and biochemical parameters of rats. Methods Grains of milk kefir (whole and skimmed) and water kefir (brown sugar) were used. The chemical composition analysis was performed on substrates and fermented beverages. The rats were evaluated for weight gain, body mass index, as well as their food, water, kefir, and calorie intake. We also evaluated their energy efficiency coefficient, weight of organs, in addition to their serum, and hepatic biochemistry. Results Fermentation increased the acid content index owing to degradation of lactose and brown sugar. The animals consumed more kefir, reducing the intake of chow and water. Kefir did not alter body and organ weight, while improving the lipid profile. Conclusion Water kefir with brown sugar was more effective in improving the lipid profile.

RESUMO Objetivo Este estudo tem como objetivo comparar os efeitos dos fermentados de kefir sobre parâmetros nutricionais, fisiológicos e bioquímicos de ratos. Métodos Foram utilizados grãos de kefir de leite (integral e desnatado) e de água (açúcar mascavo). A composição química foi realizada nos substratos e fermentados. Foram avaliados nos ratos: ganho de peso; índice de massa corporal; ingestão de ração, água, kefir e calorias; coeficiente de eficiência energética; peso dos órgãos; e bioquímica sérica e hepática. Resultados A fermentação elevou o índice de compostos ácidos a partir da degradação da lactose e do açúcar mascavo. Os animais consumiram mais kefir, diminuindo a ingestão de ração e água. O kefir não alterou o peso corporal e dos órgãos, melhorando ainda o perfil lipídico. Conclusão O kefir de água com açúcar mascavo foi mais eficaz na melhora do perfil lipídico.

The characteristics of lactic acid bacteria isolated from Indonesian commercial kefir grain

Aims@#Kefir is a fermented dairy product using lactic acid bacteria, such as Lactobacillus lactis and L. delbrueckii subsp. bulgaricus mixed with yeast and produces acids and alcohols. Lactic acid bacteria (LAB) can be identified based on morphological and biochemical characteristics, using macroscopic and microscopic examination and biochemical tests. This study aims to isolate LAB from commercial kefir grain and to conduct an identification based on morphological characteristics using macroscopic, microscopic and biochemical techniques. @*Methodology and results@#LAB isolated from kefir grain was grown on nutrient-agar medium and then transferred to the MRS agar medium. Macroscopic observations included recording the colony size, color, form, surface, and edge. Microscopic examination involved Gram staining and spore staining. Biochemical assays included oxidase test and aerobic and anaerobic tests. The results obtained were lactic acid bacteria which were negative in the catalase and oxidase tests, positive for Gram staining, spore staining was negative, and aerobic and anaerobic tests were positive; the bacteria were rod-shaped and rounded. @*Conclusion, significance and impact of study@#Lactic acid bacteria isolated from kefir grains were identified by macroscopic and microscopic examination of morphology and using biochemical tests putatively identified as Lactococcus cremoris, Streptococcus cremoris and L. plantarum.

Milk and açaí berry pulp improve sensorial acceptability of kefir-fermented milk beverage / Leite e polpa de açaí aumentam a aceitabilidade sensorial de uma bebida fermentada por kefir

Kefir grains are a symbiotic biomass (yeast and bacteria) commonly used to produce milk probiotic fermented beverages. The aim of this study was to produce a mixed beverage of whole milk and açaí (Euterpe oleracea) berry pulp fermented by two different kefir cultures: one specific for milk and one specific for sugared water, adapted to milk. Based on the fermentation yield, pH and sensory analysis, the culture adapted to milk obtained the best results in a composition (g 100 g-1) of 70 of whole milk and 30 of açaí berry pulp, at room temperature (~25°C), without agitation and fermented for 24 h. The results obtained by this formulation were an increase of 12% in the kefir biomass, 93% of fermentation yield, pH 5.10 and overall sensory acceptance of 7.05.

Kefir é uma biomassa simbiótica (leveduras e bactérias) comumente aplicada na obtenção de bebidas fermentadas probióticas de leite. O objetivo deste trabalho foi produzir uma bebida fermentada mista de leite integral e polpa de açaí (Euterpe oleracea) a partir de duas culturas diferentes de kefir: uma original de leite e outra original de água açucarada e adaptada ao leite. Com base na conversão, pH e análise sensorial, os melhores resultados foram obtidos com a cultura adaptada na composição (g 100 g-1) de 70% de leite e 30% de polpa de açaí, sem controle de temperatura (temperatura ambiente ~25° C) e sem agitação e por 24 h de fermentação. Esta formulação apresentou 12% de aumento da biomassa, 93% de conversão, pH 5,10 e uma aceitação global de 7,05.

Propriedades antimicrobianas do kefir / Antimicrobial properties of kefir

Os leites fermentados têm sido amplamente consumidos desde a Antiguidade e, atualmente, comercializados em todo o mundo. Kefir é um leite fermentado, ácido, levemente alcoólico, produzido artesanalmente a partir da fermentação do leite pelos grãos de kefir, os quais contêm uma população estável de micro-organismos. O processo fermentativo gera uma série de compostos que conferem sabor e aroma característicos ao kefir, além de substâncias bioativas, responsáveis por propriedades nutracêuticas. A utilização de micro-organismos com propriedades antimicrobianas como conservantes naturais é uma alternativa que tem como vantagem a inibição do desenvolvimento de bactérias deteriorantes e patogênicas sem o uso de substâncias químicas indesejáveis. O interesse em tais espécies aumentou nos últimos anos, viabilizando o uso desses micro-organismos probióticos como conservantes e inibidores naturais em vários produtos de origem animal, como leites, carnes e derivados. O objetivo deste trabalho foi apresentar uma revisão da literatura sobre as propriedades antimicrobianas atribuídas ao kefir.(AU)

The fermented milks have been consumed since the antiquity, and currently it have been widely marketed and consumed around the world. Kefir is a fermented, acid, mildly alcoholic homemade milk produced from the fermentation of milk by kefir grains which contain a stable population of microorganisms. The fermentation process generates a series of compounds which impart flavor and aroma to kefir, and bioactive substances responsible for nutraceutic properties. The use of micro-organisms with antimicrobial properties as natural preservative is an alternative that has the advantage of inhibiting the development of pathogenic and spoilage bacteria without the use of undesirable chemicals. The interest in these species has increased in recent years, enabling the use of these probiotic micro-organisms as preservatives and natural inhibitors in several animal products such as milk, meat and their products. The aim of this paper is to present a review of literature on the antimicrobial properties attributed to kefir.(AU)

Biosurfactant production by Pseudomonas aeruginosain kefir and fish meal

The aim of this study was to increase rhamnolipid production by formulating media using kefir and fish meal for Pseudomonas aeruginosa strains isolated from different environmental resources. The strains, named as H1, SY1, and ST1, capable of rhamnolipid production were isolated from soil contaminated with wastes originating from olive and fish oil factories. Additionally, P. aeruginosa ATCC 9027 strain, which is known as rhamnolipid producer, was included in the study. Initially, rhamnolipid production by the strains was determined in Mineral Salt Medium (MSM) and then in media prepared by using kefir and fish meal. The obtained rhamnolipids were purified and quantified according to Dubois et al. (1956). The quantity of rhamnolipids of ATCC, H1 and SY1 strains in kefir media were determined as 11.7 g/L, 10.8 g/L and 3.2 g/L, respectively, and in fish meal media as 12.3 g/L, 9.3 g/L and 10.3 g/L, respectively. In addition, effect of UV light exposure on rhamnolipid production was also investigated but contrary a decrease was observed. The results indicate that P. aeruginosa strains isolated from various environmental resources used in this study can be important due to their rhamnolipid yield, and fish meal, which is obtained from waste of fish, can be an alternative source in low cost rhamnolipid production.

Capacidad antifúngica de sobrenadantes libres de células obtenidos de la fermentación de un sustrato de "panela" con gránulos de kéfir de agua / Antifungal capacity of cell-free supernatants obtained from fermentation of a substrate of brown sugar with water kefir grains

El kéfir de agua (KA) es una bebida fermentada medianamente ácida elaborada con soluciones azucaradas y fermentada por un consorcio de microorganismos, principalmente bacterias ácido lácticas (BAL) y levaduras (LEV), embebidas en un polisacárido llamado gránulo de KA. La presencia de hongos y sus toxinas es un problema de la producción de alimentos, como Aspergillus ochraceus y sus micotoxinas especialmente en café y vino. Entre algunas alternativas que se han evaluado para su inhibición se incluyen las bacterias ácido lácticas y productos fermentados en general. El objetivo principal de esta investigación fue evaluar la capacidad del KA en inhibir o retrasar el crecimiento de A. ochraceus. Se emplearon 8 sobrenadantes libres de células (SLC) obtenidos de diferentes fermentaciones de panela con gránulos de KA y con diferentes concentraciones de ácidos orgánicos (láctico y acético). Se hicieron fermentaciones con gránulos de KA en solución de panela por periodos de 32,5 h, a 25, 30 y 37 °C. Se determinaron la cinética de acidificación; el incremento de biomasa y se hizo el recuento de los grupos de microorganismos que componen el gránulo. A 25 °C se determinó el mayor aumento de biomasa (92%). La temperatura de fermentación afectó el recuento de los microorganismos que conforman el gránulo, principalmente las BAL, disminuyendo su cantidad a la máxima temperatura de fermentación (37 °C) (1x10ˆ6 UFC ml-1), comparado con la mínima temperatura (25 °C) (6x10ˆ7 UFC ml-1). El fermento que presentó mayor actividad antifúngica fue el SLC5 (pH: 3,2; temperatura de fermentación: 30 °C). El poder inhibitorio se atribuyó a los ácidos orgánicos producidos durante la fermentación, aunque no se puede descartar que hayan actuado otras sustancias no cuantificadas. Se pudo comprobar que el KA puede fermentar y aumentar su biomasa en un sustrato como el agua de panela y que sus SLC tienen la capacidad de reducir el crecimiento de A. ochraceus.

Water kéfir (WK) is a moderately sour fermented beverage elaborated in sugar-containing solutions through fermentation by a microorganism consortium, principally lactic acid bacteria (LAB) and yeasts, embedded in a matrix of polysaccharide so-called WK grains. The presence of fungi and their toxins it is a problem for the food industry, such as Aspergillus ochraceus and their mycotoxin production especially in coffee and wine. Some alternatives that have been evaluated for their inhibition include lactic acid bacteria and generally fermented products. The main objective was to evaluate the capacity of WK to ferment a Colombian beverage made with Panela and to assess capability of this product to retard the germination of a common toxigenic fungi like Aspergillus ochraceus. 8 cell-free supernatants (CFS) were obtained from separate fermentations and with different organic acids (OA) concentrations (e. g., lactic and acetic). Different fermentations were conducted with WK in Panela broth during 32.5 h periods at 25, 30, and 37°C. We determined the kinetics of acidification of WK along with the corresponding increment in biomass and conducted a quantitation of microorganisms groups that composed the grain. The greatest biomass increase occurred at 25 °C (92%); but the fermentation temperature affected the composition of microorganisms conforming the grain, with the quantity of LAB decreasing at the highest fermentation temperatures (37 °C) (1x10ˆ6cfu ml-1), compared with the minimum temperature (25 °C) (6x10ˆ7 cfu ml-1). The CFS5 (pH 3.2; fermentation temperature 30 °C) exhibited the greatest antifungal activity. We attribute the inhibitory power of these ferments to the OA produced during fermentation, although we cannot discard the possibility of the action of other substances not specifically quantified. We concluded that WK can grow and fermentate Panela broth and that its CFS can exert an antifungal effect against A. ochraceus.

Evaluation of a functional soy product with addition of soy fiber and fermented with probiotic kefir culture

The objective of this study was to evaluate the chemical, sensory properties and stability of a functional soy product with soy fiber and fermented with probiotic kefir culture. The product was characterized by the chemical composition, color and sensory analysis. The stability of the product was evaluated by pH, acidity, viscosity, firmness, syneresis measurements and cells counts. The functional soy product presented better chemical composition and difference in color compared to the fermented product without fiber. Sensory analysis showed that the functional soy product had good acceptance and had better firmness and reduced syneresis compared to fermented product without fiber. The lactic acid bacteria counts decreased slightly during 28 days at 4°C of the storage and the product showed good microbiological stability. The functional soy product due to high Lactococcus lactis counts could be considered as a probiotic for the entire storage period.

Inhibición del crecimiento de Aspergillus ochraceus mediante "panela" fermentada con gránulos de kefir de agua / Fungal growth inhibition of Aspergillus ochraceus with "panela" fermented with water kefir grains

Antecedentes: El kéfir de agua (KA) es una bebida producida con soluciones azucaradas fermentadas con gránulos constituidos por bacterias ácido lácticas (BAL) y levaduras embebidas en una matriz de polisacárido. Aspergillus ochraceus es un hongo filamentoso micotoxigénico, contaminante frecuente y productor de ocratoxina en café, uvas y vino. Se ha estudiado la actividad antifúngica de productos fermentados por BAL pero hasta ahora no se conocen estudios sobre la capacidad antifúngica del KA. Objetivos: Evaluar la capacidad antifúngica de soluciones de panela fermentadas a diferentes tiempos y temperaturas con KA sobre A. ochraceus. Métodos: Se inocularon 10 µL de una suspensión (3x107 conidios. ml-1) de A. ochraceus en agar malta mezclado con sobrenadantes libres de células (SLC) de los productos fermentados, incubando a 25°C y midiendo diariamente el diámetro del micelio, con lo cual se determinó el efecto antifúngico sobre la tasa de crecimiento y la fase de latencia. Se determinó la concentración de ácidos orgánicos (AO) en los SLC mediante HPLC. Resultados: Los productos fermentados por mayor tiempo y temperatura tuvieron mayor concentración de (AO) y mayor descenso de pH siendo el SLC8 (pH: 2,8) el más inhibitorio. Conclusiones: La solución de panela en agua fue adecuada para fermentación con gránulos de KA, obteniéndose metabolitos con propiedades antifúngicas como los AO.

Evaluation of antagonistic activity of milk fermented with kefir grains of different origins

In this study, the potential of kefir grains, obtained from three different towns/cities in the Southeast Region of Brazil to inhibit the growth of the five pathogenic microorganisms was evaluated. The samples showed the growth inhibition from 42.80-69.15 for Staphylococcus aureus ATCC 6538, 30.73-59.89 for Escherichia coli ATCC 11229, 44.99-73.05 for Salmonela typhi ATCC 6539, 41.45-54.18 for Listeria monocytogenes ATCC 15313 and 70.38-86.80 for Bacillus cereus RIBO 1222-173-S4. These results indicated that the kefir grains evaluated had antagonistic activity toward the different pathogens tested. The ability to inhibit, although differently depending on the regional microbiota, indicated a potential for their use as a functional food.

Níveis séricos de cortisol basal em ratos sob tratamento oral com kefir / Basal serum cortisol in rats under treatment with oral kefir

A via de metabolismo do kefir ainda é desconhecida em muitas funções, pois há poucos estudos que a evidenciam. Assim a proposta do presente estudo é avaliar o efeito do kefir sobre os níveis séricos de cortisol basal. Um Estudo experimental em que foram utilizados 60 ratos, machos, wistar, peso de 180±30g, sendo 20 animais de experimento por 07, 14 e 21dias, divididos em Kefir 20g/200ml (GK); Dexametasona 0,125mg/kg (GD); Ranitidina 0,85mg/kg (GR); Omeprazol 0,68mg/kg (GO); Controle água ad libitum (GCO). Os resultados foram avaliados pelo Software BioEstat 5.0, e para verificação do nível de significância (α<5%) usou-se a ANOVA com o teste Tukey-kramer e Bartlett’s test. Os resultados obtidos revelaram que o cortisol basal (μg/dL) do sangue de 60 ratos (Rattus norvegicus) submetidos ao tratamento, com D7 (P<0.05), evidenciou no GR uma média representativa sobre os demais grupos com 2.2075 μg/dl, e desvio padrão (SD) de 0.4329 μg/dl. Já em D14, as alterações evidenciadas foram relativamente mínimas e pouco representativas, com D21 quando relacionado o GO e GR (P<0.01), ao que tange a relação entre o GK e o GD apresentou diferenças significativas (P< 0,001). A média no GK foi de 3,4 μg/dl com um SD de 0,3238 μg/dl sobre os demais grupos experimentais, o GD apresentou níveis muito baixos de cortisol com 0,0275μg/dl e o SD de 0,009574 μg/dl. Conclui-se que o Kefir, quando consumido em doses contínuas e diariamente, repercutiu na elevação dos níveis séricos de cortisol. Não foi possível estabelece a via de mecanismo que tenha contribuído para tal, entretanto, esse aumento ocorreu sem que os animais sofressem qualquer tipo de dano, ou seja, os animais submetidos ao tratamento com kefir mostraram-se mais vistosos, pelagem firme e com brilho, esboçando aspecto saudável.

The metabolism pathway of kefir remains unknown with regard to many functions due to the few studies that have addressed this issue. The purpose of the present investigation was to evaluate the effect of kefir on basal serum cortisol. For such, 60 male Wistar rats (Rattus norvegicus) weighing 180 ± 30 g were allocated to the following five groups: kefir group (KG) – 20 g/200 ml; dexamethasone group (DG) – 0.125 mg/kg; ranitidine group (RG) – 0.85 mg/kg; omeprazole group (OG) – 0.68 mg/kg; and control group (CG) – water ad libitum. Evaluations were carried out on Days 7, 14 and 21 (20 animals per evaluation). Statistical analysis involved ANOVA with the Tukey-Kramer test and Bartlett’s test, with the level of significance set to 5% (p < 0.05). All analyses were performed with the aid of the BioEstat 5.0 program. At the Day 7 evaluation, a significant increase (p < 0.05) in basal cortisol was found in the RG (2.2075 ± 0.4329 μg/dL), whereas non-significant changes were found at the Day 14 evaluation. At the Day 21 evaluation, significant changes were found in the OG and RG (p < 0.01). Moreover, significant differences were found between the KG and DG (p < 0.001); mean cortisol level in the KG was 3.4 ± 0.3238 μg/dL, whereas a very low cortisol level was found in the DG (0.0275 ± 0.009574 μg/dL). Based on the present findings, kefir leads to elevated serum cortisol when consumed in continuous, daily doses. While it was not possible to establish the mechanism that contributed to this result, the increase occurred apparently without causing harm, as the animals submitted to kefir had a firm, shiny coat and appeared healthy.

Microbiological, technological and therapeutic properties of kefir: a natural probiotic beverage

Kefir is a fermented milk beverage produced by the action of bacteria and yeasts that exist in symbiotic association in kefir grains. The artisanal production of the kefir is based on the tradition of the peoples of Caucasus, which has spread to other parts of the world, from the late 19th century, and nowadays integrates its nutritional and therapeutic indications to the everyday food choices of several populations. The large number of microorganisms present in kefir and their microbial interactions, the possible bioactive compounds resulting of microbial metabolism, and the benefits associated with the use this beverage confers kefir the status of a natural probiotic, designated as the 21th century yoghurt. Several studies have shown that kefir and its constituents have antimicrobial, antitumor, anticarcinogenic and immunomodulatory activity and also improve lactose digestion, among others. This review includes data on the technological aspects, the main beneficial effects on human health of kefir and its microbiological composition. Generally, kefir grains contain a relatively stable and specific microbiota enclosed in a matrix of polysaccharides and proteins. Microbial interactions in kefir are complex due to the composition of kefir grains, which seems to differ among different studies, although some predominant Lactobacillus species are always present. Besides, the specific populations of individual grains seem to contribute to the particular sensory characteristics present in fermented beverages. This review also includes new electron microscopy data on the distribution of microorganisms within different Brazilian kefir grains, which showed a relative change in its distribution according to grain origin.

Identification and assessment of kefir yeast potential for sugar/ethanol-resistance

Biochemical and molecular analysis was used for identification of different kefir yeasts species from Brazil, Canada and the United States of America. The sugar/ethanol-resistant activity of the yeasts was evaluated. Saccharomyces cerevisiae and Kluyveromyces marxianus had the highest growth rates, suggesting biotechnological applications possible for these strains.