Kefir Beverage Research Articles

Microbial community dynamics of fermented kefir beverages changes over time

Kefir is a traditional fermented milk associated with several health benefits, such as immune system modulation, as well as antimicrobial, antitumor and antioxidant activity. The aim of the current study was to investigate the microbial dynamics of kefir production based on high‐throughput DNA sequencing. Results of sequence analysis have grouped the reads into 303 and 112 amplicon sequence variants (ASV) for bacteria and fungi, respectively. Firmicutes, Bacteroidetes and Proteobacteria were the prevalent bacterial phyla, whereas Lactococcus was the prevalent bacterial genus. Ascomycota was the main fungal phylum. Data have shown heterogeneity in diversity and abundance distributions between milk kefir samples.

Process Optimization for Development of a Novel Water Kefir Drink with High Antioxidant Activity and Potential Probiotic Properties from Russian Olive Fruit (Elaeagnus angustifolia)

Kefir is a dairy-based probiotic beverage with high antioxidant activity, among other health benefits. To extend kefir’s beneficial health effects to non-dairy consumers, studies on kefir fermentation using alternative matrices (referred to as water kefir) are needed. As such, the purpose of this study was to formulate a novel water kefir beverage using Russian olive, as a non-dairy product with high antioxidant activity and potential probiotic properties. To this end, the Russian olive kefir water (RWK) fermentation process was optimized to maximize the total phenolic content, antioxidant activity, and microbial viability of this product. The experimental design was set using a rotatable central composite design with response surface methodology (RSM). The optimized independent variables included the substrate concentration (20–30% of Russian olive juice), fermentation time (24–48 h), and incubation temperature (20–32 °C). The optimal fermentation conditions were observed to be 31.2 °C incubation temperature, 24 h incubation time, and 30% Russian olive juice concentration. Under these conditions, the values for FRAP antioxidant activity, DPPH radical scavenging, and TPC in RWK were 0.22 (μmol FSHE/mL), 0.096 (μmol Trolox Eq/mL), and 98.32 (μg GAE/mL), and the microbial viability (of AAB, LAB, and yeasts) was 7.20, 7.06, and 7.17 log10 CFU/mL, respectively.

Chemical, microbiological and sensory viability of low-calorie, dairy-free kefir beverages from tropical mixed fruit juices

ABSTRACT The use of non-dairy matrices for probiotic delivery can be beneficial for vegetarian, vegan and lactose intolerant consumers. Stevia rebaudiana extract can be used as sweetener to replace sucrose for glucose intolerants. This research evaluated the use of kefir grains to prepare a low-calorie, fruit-based kefir beverage. Fermentation was carried out by inoculating kefir grains into a mixture of mango and umbu pulps. Two beverages, one containing sucrose, and the other, stevia, were characterized according to their proximate composition and submitted to a 30-day shelf-life period at 5°C, evaluating lactic acid bacteria, yeasts, pH, acidity, color parameters, soluble solids, ascorbic acid, sensory acceptance, and purchase intention every 10 days. Lactic and acetic acids were analyzed at the beginning and end of the shelf-life. Both beverages showed probiotic potential. The stevia-sweetened beverage had lower calorie content and good sensory acceptance. These results support the possibility to develop low-calorie, fruit-based kefir beverages.

KEFIR OF KEJI BELING TEA (Strobilanthes crispus) AS FUNCTIONAL BEVERAGE FOR GLUCOSE INTOLERANCE

Kefir is beverage fermented product, it is usually made from milk. However, there is an arising concern about lactose intolerant. Therefore, taking benefit of herbal tea solution as raw material of kefir will give multiple benefits. The used tea solution was made from keji beling leaves (Strobilanthes crispus L.) which has many benefits. Kefir beverage is probiotic beverage which is beneficial for digestion health and can keep immune system, as well as keji beling tea which is rich in antioxidants. The used design in this research was Complete Randomized Design (Rancangan Acak Lengkap) with 4 levels of treatment namely: concentration of keji beling 0%, 10% and 15% with fermentation duration of 12 hours and 24 hours. Based on the research result pointed out the obvious effect between treatment toward pH, total polyphenols, total acetic acid, and total glucose with p score = 0,00. The result of lactic acid bacteria (BAL) total is 1,914 x107 CFU/mL and yeast total is 1,532 x 107 CFU/mL on concentration of 15% kefir of keji beling tea with fermentation duration of 24 hours. Result for organoleptic test shows the obvious effect (p=0,00) between the treatment toward parameters of taste, aroma, color and power. Panelist takes pleasure on the treatment P1 with concentration of horsewhip tea 150% in fermentation duration of 24 hours. Key words : Kefir, Keji beling tea (Strobilanthes crispus L), Fermented Beverage.

Physicochemical composition and fermentation kinetics of a novel Palm Sap-based Kefir Beverage from the fermentation of Borassus aethiopum Mart. fresh sap with kefir grains and ferments

Palm sap collected (sugary juice) from palm trees is very widespread in the intertropical regions of Asia, America and Africa. This study aimed to evaluate the use of kefir grains and ferments as starters for the fermentation of fresh palm sap (PS) from Borassus aethiopum Mart. to produce new kefir-like beverages (KLBs). The batch fermentation was performed statically at room temperature (22 °C) during 48 h. Physicochemical analysis were performed using standard and HPLC methods. The KLBs (kefir-like beverages) from PS showed low ethanol and glycerol contents ranging from 0.84 ± 0.14 to 17.30 ± 2.06 g/L (0.07 to 1.38% v/v) and 0 to 0.67 g/L respectively. The pH value decreased significantly during 24 h of fermentation and ranging from 3.98 to 4.40 at the end of fermentation. The organic acids (lactate, acetate, propionate, citrate, succinate and pyruvate) were detected in KLBs from PS. There was an increase in the content of lactate, acetate, propionate and succinate during fermentation process, except citrate content. Lactate and acetate content reached maximum values ranging between 5.18 and 9.31 g/L, 0.94 and 1.69 g/L respectively. Sucrose concentration decreased significantly and reached a value ranging from 0 to 0.84 g/L, except in KLBs fermented using milk ferments (9.45 g/L). The study showed that water and milk kefir grains as well as kefir ferments were well adapted to ferment Borassus aethiopum Mart. fresh sap for KLBs production. Palm sap could be an ideal alternative base substrate to produce non-dairy probiotic fermented beverage with low ethanol and sugar contents.

Utilization of Kefir Beverages as a Preventive Action Part of Pneumonia Infection

Introduction: Pneumonia is an acute infection of the lungs and can be caused by bacteria, viruses, fungi, chemical exposure or the influence of other infections. Pneumonia is one of the diseases that cause the most deaths in the world after diarrhoea. Pneumonia caused by several microorganisms includes Haemophilus influenza type B (HiB), Streptococcus pneumonia, influenza virus and respiratory syncytial virus (RSV). The use of antibiotics is now one of the important treatments for the management of pneumonia. However, with the challenge of antimicrobial resistance, therapy is needed to eradicate pathogens and prevent resistance. One probiotic drink that has potential in the treatment of pneumonia is kefir. The development of science now shows the potential of kefir probiotic drinks to prevent pneumonia infection.
 Discussion: This literature study proves that probiotic drinks have an antibacterial effect to prevent pneumonia infection. The complex content of probiotic bacteria between specific lactic acid bacteria, acetic acid-producing bacteria and lactose and non-lactose fermenting bacteria that symbiotic with each other stimulates the immune system to be used for pathogens of pneumonia infection. The component of probiotic bacteria in kefir can reduce the level of antibiotic and antimicrobial consumption which can complicate the treatment of pneumonia infections.
 Conclusion: Probiotic drinks from kefir which have a high content of probiotic bacteria can reduce the risk of pneumonia infection

Draft Genome Sequences of Lactobacillus plantarum Strain K03D08 and Acetobacter syzygii Strain K03D05, Isolated from a Kefir Beverage Collected in Chile.

Kefir is an ancestral food produced using microbial consortia whose composition varies depending on the geographical origin and the substrate used for fermentation. This dairy beverage is considered a probiotic food, and its consumption has been associated with several health benefits. This report describes the isolation of bacterial strains from Chilean kefir.

Possible Kefir Biological Effects: 4: Effect of Kefir Beverage on The Histopathological and Macroscopical Changes in Adipose Tissue of High Fat-Fed STZ- Induced Diabetic Male Wistar Rat

This study was designed to investigate the effect of kefir consumption as a common dairy fermented product on keep the bodyweight balanced on high fat-fed streptozotocin-induced diabetic wistar rats which fed with a daily kefir gavage dose, also to examine any effects regards the abdominal circumference (AC) and body fat mass; observed results compared to normal male rats; Experiments were carried out on 60 albino male rats, with age 8 weeks, weighing about 220-250 g, after the adaptation period, male rats were divided randomly into two experiments by six groups: experiment Ⅰ included 3 non-diabetic ones and experiment ⅠⅠ included three STZ induced diabetes groups. The groups were fed as follows: group 1 received a standard diet and served as control. Group 2 was fed on a standard diet and kefir (0.7 ml/animal/day by gavage). Group 3 received a high-fat diet and kefir (0.7 ml/animal/day by gavage). The diabetic males of groups A, B and C were fed on a high-fat diet. Group B received in addition kefir (0.7 ml/animal/day by gavage), while group C was injected additionally with insulin (0.76 UI/200 mg BW/day); all the groups have the access to the drinking water all the time.; the bodyweight of normal and diabetic rat males was determined on 1sttreatment day,and every week until the end the experiment plan (5 weeks) then all the groups were sacrificed with measuring the AC and weighting the fat mass; Summarizing it could be said; through all the work plan (5 weeks), all the six animal groups showed a significant increase in the mean body weight with a normal level in experiment Ⅰ unless in group 3 which fed on HFD and kefir, while in experiment ⅠⅠ kefir helps the diabetic treated group to not losing weight compared to the untreated one; similarity kefir neither affect AC nor relative fat weight.

Substantiation and development of technology for a new assortment of combined sour-milk drinks based on bio modified bean raw materials

Abstract Biologically complete combination products have a balanced chemical composition due to the combination of raw materials of animal and vegetable origin. In this aspect, research aimed at the development and creation of dairy and vegetable food of functional purpose are relevant. The article deals with the creation of a combined fermented milk drink such as kefir using milk from sprouted horse bean seeds and natural cow's milk. The possibility of obtaining and applying bean milk from germinated sprouted seeds for the development of the technology of combined fermented milk kefir beverage has been investigated. The mode and technology of obtaining bean milk and kefir drink with it was justified. The inclusion of bean milk from germinated seeds of horse beans, which are completely free from the presence of anti-nutritional components and the action of antitrypsin and hemagglutinin enzymes, is successfully combined with natural milk to develop a new assortment of milk-vegetable sour-milk beverage. Organoleptic evaluation and quality characteristics of acidity showed that the use of milk from beans sprouted seeds instead of part of the milk in the manufacture of kefir drinks, leads to the preparation of samples with improved technological parameters and contributes to the development of healthy milk microflora.

Microbiological characterization of Gioddu, an Italian fermented milk

Gioddu, also known as “Miciuratu”, “Mezzoraddu” or “Latte ischidu” (literally meaning acidulous milk), is the sole variety of traditional Italian fermented milk. The aim of the present study was to elucidate the microbiota and the mycobiota occurring in artisan Gioddu sampled from three Sardinian producers by combining the results of viable counting on selective culture media and high-throughput sequencing. Physico-chemical parameters were also measured. The overall low pH values (3.80–4.22) recorded in the analyzed Gioddu samples attested the strong acidifying activity carried out by lactic acid bacteria during fermentation. Viable counts revealed the presence of presumptive lactococci, presumptive lactobacilli and non-Saccharomyces yeasts. A complex (kefir-like) microbiota of bacteria and yeasts was unveiled through sequencing. In more detail, Lactobacillus delbrueckii was found to dominate in Gioddu together with Streptococcus thermophilus, thus suggesting the establishment of a yogurt-like protocooperation. Unexpectedly, in all the three analyzed batches from two out of the three producers Lactobacillus kefiri was also detected, thus representing an absolute novelty, which suggests the presence of bioactive compounds (e.g. exopolysaccharides) similar to those characterizing milk kefir beverage. Mycobiota population, studied for the very first time in Gioddu, revealed a more complex composition, with Kluyveromyces marxianus, Galactomyces candidum and Geotrichum galactomyces constituting the core species. Further research is needed to disclose the eventual occurence in Gioddu of probiotic cultures and bioactive compounds (e.g. exopolysaccharides, angiotensin-converting enzyme inhibitory peptides and antimicrobial compounds) with potential health-benefits for the consumers.

Development of a Novel Whey Date Beverage Fermented with Kefir Grains Using Response Surface Methodology

The aim of this study was to develop a novel kefir beverage using date syrup, whey permeate, and whey. The levels of the kefir grain inoculum (2–5% w/v), fruit syrup (10–50% w/v), and whey permeate (0–5% w/v) on pH, total phenolic content, antioxidant activity, lactic acid bacteria and yeast counts, and overall acceptability were investigated using central composite design. The use of response surface methodology allowed us to obtain a formulation with acceptable organoleptic properties and high antioxidant activities. The obtained beverages had total phenolic content, % DPPH scavenging activity, and overall acceptability ranging from 24 to 74 mg GAE/mL, from 74.80 to 91.37 mg GAE/mL, and from 3.50 to 6 mg GAE/mL (based on a 1 to 9 preference scale), respectively. Date syrup of 36.76% (w/v), whey permeates of 2.99%, and kefir grains inoculum size of 2.08% were the optimized process conditions achieved.

Health beliefs towards kefir correlate with emotion and attitude: A study using an emoji scale in Brazil.

Emojis can be used to explore food-evoked emotions in order to provide information that can support the product development and marketing decisions. This study aimed to evaluate consumers' acceptance, purchase intent and emotional responses to milk beverages, with and without kefir added, before and after these consumers were informed about the products' composition (0%, 15%, 30% and 50% m/v) and health claims toward kefir (blind and informed tests, respectively). Emotional responses were assessed by emoji use within a RATA questionnaire in order quantify the perceived significance of the emojis chosen. In the informed test, the consumers' perception of the sensory attributes of the milk beverages, such as their perception of an acid taste in added kefir beverages was shown to have changed. Overall, participants attributed significantly higher acceptance and purchase intent scores to added kefir beverages after they had been informed on its health benefits. In addition, expressions of positive emotion increased when participants were exposed to stimuli related to health benefits of kefir (15%, 30% and 50% m/v), while negative expressions of emotion decreased. The provided information of kefir modified valence and arousal in subjects, and it can be said that to 30% of kefir can be added to yogurt without compromising its sensory acceptability. Thus, health benefits alone cannot improve product acceptance, since participants found a 50% addition of kefir to be unpleasant when tasted during a blind test. Mixed beverages may present a probiotic beverage alternative for consumers who dislike kefir milk, but want to include it in their diets. The implications of liking and purchase intent and how they are linked to emotions are discussed in this paper as well.

Bacterial and Fungal Communities of Gioddu as Revealed by PCR-DGGE Analysis.

Gioddu is the sole variety of fermented milk originating in Italy. Despite the long history of consumption, Gioddu still represents an undisclosed source of microbial diversity. The present study was aimed to get an insight into the bacterial and fungal diversity of Gioddu samples collected from two artisan producers located in Sardinia. To this end 3 batches of Gioddu were collected from each producer and subjected to Polymerase Chain Reaction-Denaturing Gradient Gel Electrophoresis (PCR-DGGE) analyses. Gioddu was produced with sheep milk in accordance with the local tradition. Regarding the bacterial population, a low biodiversity emerged. In more detail, the sole species Lactobacillus delbrueckii subsp. bulgaricus was detected in all the samples, irrespective of the producer or the batch. A more ample microbial diversity was highlighted for the fungal population that included closest relatives to Pichia cactophila, Kluyveromyces marxianus and Galactomyces candidum. Based on the results, the detected bacterial and fungal species generally clustered in accordance with the producer, irrespective of the batch considered. It is noteworthy that, Gioddu revealed several microbiological similarities with kefir beverage, thus suggesting, by analogy, potential health benefits related to its consumption. More research is needed to better clarify the microbiota composition of Gioddu by using more powerful metagenomic techniques.

In Vitro Probiotic Properties and DNA Protection Activity of Yeast and Lactic Acid Bacteria Isolated from A Honey-Based Kefir Beverage.

The probiotic characteristics of three acid-tolerant microbial strains, viz., Lactobacillus satsumensis LPBF1, Leuconostoc mesenteroides LPBF2 and Saccharomyes cerevisiae LPBF3, isolated from a honey-based kefir functional beverage, were studied following the requirements established by the Food and Agriculture Organization of the United Nation/World Health Organization (FAO/WHO), including host-associated stress resistance, epithelium adhesion ability, and antimicrobial activity. The three microbial strains tolerated different pH values (2.0, 3.0, 4.0 and 7.0) and bile salt concentrations (0.3% and 0.6%), and survive in the presence of simulated gastric juice, which are conditions imposed by the gastrointestinal tract. In addition, they showed high percentages of hydrophobicity, auto aggregation and anti-pathogenic against Escherichia coli and Staphylococcus aureus, with no hemolytic activity. The protective capacity of human DNA through microbial treatment was investigated by single-cell gel electrophoresis (SCGE) comet assay. The three selected strains showed DNA protection effect against damage caused by hydroxyl radical (H2O2). However, when the S. cerevisiae treatment was applied, the most effective DNA protection index was observed, which can be associated to its high production of extracellular antioxidants as reveled by the 2,2-diphenyl-1-picryl-hydrazylhydrate (DPPH) method. These results indicated that the three selected microbial strains could be useful for preventing oxidative DNA damage and cellular oxidation in food products. As well-adapted microbial cells, the selected strains can be used for production of non-dairy functional beverages, especially for vegans and/or vegetarians and lactose intolerants.

Functional kefir production from high pressure homogenized hazelnut milk

This research aimed to evaluate the waste product of cold pressed hazelnut oil for the fortification of kefir beverage. Hazelnut cake was processed to a drinkable beverage that is called as hazelnut milk (HM). The effect of hazelnut milk on physicochemical, rheological, structural, bioactive properties, organic acids profiles and viability of kefir microorganisms was evaluated during storage. Fermentation process was also evaluated by watching acidification kinetics and microorganism growth. Addition more than 50% hazelnut milk resulted to prolong incubation time compared to control sample and also slowed the bacteria growth during fermentation. Hazelnut milk showed stimulating effect on the growth of yeasts in kefir samples. Viscosity, consistency index, water holding capacity and exopolysaccharide content of kefir samples enhanced with the usage of hazelnut milk in the production. Hazelnut milk also led to increase in total phenolic compound content and antioxidant capacity in the kefir samples. Using different milk type changed the organic acid profiles of kefir samples. Hazelnut milk caused to reduction in lactic and citric acid contents while led to increase in malic and acetic acid content.

Identification of new bioactive peptides from Kefir milk through proteopeptidomics: Bioprospection of antihypertensive molecules

Kefir, a probiotic beverage prepared from fermented milk, has been associated with antihypertensive activity. However, the bioactive molecules responsible for this activity still remain unclear. Therefore, in this study we aim to evaluate the mechanisms of the antihypertensive effects of Kefir in the two-kidney one-clip hypertension model, and to bioprospect for bioactive peptides identified by proteomic methodologies. Treatment with Kefir was performed via gavage, and resulted in a 37 mmHg reduction in systolic arterial pressure and 19% inhibition of angiotensin converting enzyme (ACE) activity. For the proteopeptidomic study, the protein extract of Kefir beverage and non-fermented bovine milk were analysed by MALDI-TOF mass spectrometry, and their tryptic digestion products sequenced via Shotgun proteomics (Q-Exactive mass spectrometer). A list of 35 peptides with potential hypertensive activity due to ACE inhibition were identified. These results demonstrate the benefits of Kefir products, and may guide the design of new antihypertensive drugs.

Produção de bebida fermentada kefir de quinoa (Chenopodium quinoa) saborizada com cacau (Theobroma cacao) em pó

The aim of the present work was to evaluate the use of the sugary kefir grains as a starter culture for the production of a new quinoa-based (Chenopodium quinoa) kefir beverage flavored with cocoa (Theobroma cacao) powder. Fermentation was performed by inoculating kefir grains in quinoa extract and 5% brown sugar. Flasks containing kefir grains and substrates were statically incubated at 28 °C for 24 h. The microbiota of sugary kefir grains were genera Lactobacillus, Leuconostoc and Acetobacter, as well as yeasts Saccharomyces, Kluyveromyces, Lachancea and Kazachstania. After fermentation, the beverage was flavored with cocoa powder. The product was positively qualified by sensory analysis (~ 75% acceptance). This study is the first to report the production of quinoa-based kefir beverage. This result opens up perspectives for this innovative application of sugary kefir grains for developing cereal-based beverages.

Fermentation process of mulberry juice-whey based Tibetan kefir beverage production

Mixture of mulberry juice and whey was evaluated as a potential substrate for the production of a beverage by Tibetan kefir grains. Different mulberry juice addition was used. Acidity, pH, volatile flavour compounds as well as microbial communities were determined during 40 h of fermentation at 18°C. Gas chromatography-mass spectroscopy (GC-MS) analysis revealed that ethanol and 3-methyl-1-butanol were dominant alcohols, and ethyl caprylate, ethyl caprate, ethyl acetate and ethyl caproate were the most dominant ester compounds. The microbial communities of fermented beverage were close to kefir grains indicating that they had similar microbial communities gradually during the fermentation process. Lactococcus was frequently detected at the beginning and then Lactobacillus rapidly proliferated after acclimatizing to the fermentation environment. Acetobacter was steadily increasing during the fermentation process. For the fungi, Candida was frequently detected with the highest abundances in almost all samples.

Characterization of the kefir beverage produced from yam (Colocasia esculenta L.), sesame seed (Sesamum indicum L.) and bean (Phaseolus vulgaris L.) extracts.

The objective of this study was to evaluate the characteristics of kefir beverages made from yam, sesame and bean extracts after fermentation of the extracts with water kefir grains. Formulations were prepared with raw and boiled yams. To the yam extract, sesame and different percentages of white bean extract were added. The fermentation kinetics, the chemical composition and color of the extracts were analyzed. To determine the fermentation kinetic parameters, pH and titratable acidity were evaluated. The chemical composition and color of all extracts were determined before and after fermentation process. The decrease in pH and increase in titratable acidity were affected both by raw or boiler yam. The addition of bean extract favored the decrease in pH of formulations containing extracts of raw or boiled yams. Chemical composition and color of the beverages were altered after fermentation. The kefir beverage made from yam and sesame enriched with 50% beans proved to be an excellent fermentation substrate. In addition, it is a new way of consuming vegetable products, especially fermented products, which have limited diversity to serve vegan consumers and also people with certain allergies to dairy products.

Avaliação microbiológica, físico-química e aceitação sensorial do kefir com polpa de graviola

Kefir é um produto obtido através da fermentação do leite com os grãos de kefir e de culturas preparadas a partir dos grãos. Tendo em vista suas propriedades funcionais e buscando o aproveitamento de frutos da região amazônica, foi produzida uma bebida de kefir com graviola. Foram avaliadas as características microbiológicas, físico-químicas da bebida durante a estocagem refrigerada, bem como sua aceitabilidade. Os principais grupos de microrganismos presentes no kefir são bactérias lácticas como Lactobacillus, Lactococcus, leveduras, bactérias acéticas, que foram quantificadas através de contagem seletiva em meios de cultura específicos. Verificaram-se contagens similares para todos os grupos de bactérias, em torno de 109 UFC/mL com redução de dois ciclos logaritmos ao final de 28 dias de estocagem. A adição da polpa de fruta e açúcar ao kefir não influenciou o comportamento da microbiota analisada. Bactérias láticas foram isoladas dos grãos de kefir. Os nove isolados foram caracterizados como Lactococcus lactis subp. lactis. Os valores de pH não variaram significativamente durante 21 dias, somente no 28º dia de estocagem refrigerada, mas a acidez aumentou progressivamente durante todo período. A análise sensorial do kefir com polpa de graviola apresentou uma elevada aceitabilidade.