Viability Of Probiotic Bacteria Research Articles

Effects of Faba Bean (Vicia faba L.) Flour on Viability of Probiotic Bacteria During Kefir Storage

<p>Whole ground faba bean was investigated for its capability and efficiency to enhance bacterial survival and growth during kefir storage. Microbial analyses, pH and total titratable acidity (TTA) were measured in kefir samples, containing starter cultures with or without probiotic bacteria, (<em>Lactobacillus acidophilus</em><em> </em>and <em>Bifidobacterium</em><em> </em><em>lactis</em>) supplemented with whole ground faba bean during 28 days cold storage at 4 ºC. Faba bean flour supplementation (4%) stimulated bifidogenic microbial growth, increased titratable acidity linearly from day 1 to 21, and reduced pH during kefir storage. Bacterial count was strongly and positively correlated with lactic acid content and inversely associated with pH. Faba bean contributed to the additive effect on viable cell counts and pH of the probiotic co-culture (<em>Lb. acidophilus </em>and <em>B. lactis</em>), but had a distinct antagonistic effect on titratable acidity of kefir. Hierarchical cluster analysis based on the microbiological, titratable acidity and pH data differentiated kefir corresponding to the presence or absence of faba bean supplementation. Faba bean flour maintain sprobioticst ability and extends kefir shelf life.</p>

Effect of milk enriched with conjugated linoleic acid and digested in a simulator (TIM-1) on the viability of probiotic bacteria

The impact of fatty acids on the growth of lactobacilli and bifidobacteria was studied to gain insight into the beneficial effects of conjugated linoleic acid (CLA) and probiotics. Milk was enriched with CLA by adding 4% safflower oil to the cow diet, by emulsifying synthetic CLA as free fatty acids, or by emulsifying CLA as triacylglycerol, then adjusted to 1.0% or 3.25% fat and digested in a gastro-intestinal simulator. The residual fatty acid contents of milk samples containing initial fat contents of 1.0% and 3.25% were significantly different after 6 h digestion. Milk enriched with synthetic CLA and adjusted to 1.0% fat appeared to provide a digest that allowed growth of both Lactobacillus rhamnosus R0011 and Lb. rhamnosus LGG; adjustment to 3.25% fat decreased viable LGG slightly. Digestion of milk containing 3.25% fat appeared to yield a residual fatty acid mixture that may be slightly bactericidal or simply bacteriostatic.

The effect of alginate and chitosan concentrations on some properties of chitosan-coated alginate beads and survivability of encapsulated Lactobacillus rhamnosus in simulated gastrointestinal conditions and during heat processing

In this study, chitosan-coated alginate beads were produced with different concentrations of chitosan and alginate to evaluate the survival of encapsulated Lactobacillus rhamnosus GG during exposure to adverse conditions in gastrointestinal simulated juice and heat processing. The encapsulation yield of different encapsulation treatments was between 25 and 53.2%. Although there was a drastic decrease in pH within 48 h of incubation in MRS medium inoculated with free and encapsulated bacteria, no significant changes (P > 0.05) in bacterial count were observed among different encapsulation treatments. Moreover, the survival rate after gastrointestinal juice exposure of all prepared beads was 10-87 times greater than that of free cells and was significantly enhanced by increasing chitosan and alginate concentrations. The encapsulated bacteria survived significantly (P < 0.05) better than the free cells during heat exposure at 55, 60 and 65 °C: free cells experienced about 5 log cycles reduction after heat treatment at 65 °C for 30 min, whereas 40 g L(-1) alginate/10 g L(-1) chitosan-encapsulated L. rhamnosus was reduced by only 2.55 log cycles. Encapsulation effectively protected L. rhamnosus against heat treatment and gastrointestinal conditions, and this effect is important in delivering sufficient numbers of viable probiotic bacteria to the gastrointestinal tract.

Influence of some prebiotics and transglutaminase (TGase) on the viability of probiotic bacteria and quality of non fat bio-yoghurt

Results of prebiotics addition (3% inulin and 3% lactulose), yoghurt starter producing expolysaccharides (EPSYS) and transglutaminase (TGase, 0.07%) revealed that the fermentation of bio-yoghurt samples containing inulin and lactulose lasted shorter than fermentation of EPSYS - and TGase -contained samples as well as control. Inulin and lactulose resulted in slightly higher acidity (after overnight cooling) than fresh control without additives then, the acidity gradually increased with different rates during cold storage for all samples. The pH showed an opposite trend for that of acidity. The lowest pH values were recorded for inulin and lactulose- treated fresh samples, whereas the pH gradually decreased with different rates during storage. Fresh bio-yoghurt with inulin and TGase had the highest curd tension values compared with all samples while those containing inulin showed the highest significant values after 5 and 10 days of storage. Concerning curd syneresis (CS), the fresh samples made with inulin had the lowest significant CS, while the differences among the rest treatments were insignificant. The differences among the treated samples of 5 days age were insignificant and were significantly lower than those of the control, which showed the highest value after 10 days of storage. Addition of inulin and lactulose significantly increased the viability and counts of Lb. delbruekii spp. bulgricus and B. bifidum bacteria at any given storage time. On the tenth day of storage, the counts of Lb. delbruekii spp. bulgricus showed a sharp decline which was significantly different (P<0.05) from the initial counts. It was also found that adding inulin and lactulose were the best in increasing survival and counts of bifidobacteria followed by the samples containing EPSYS and TGase in order. Sensory evaluation showed that using inulin and lactulose improved body, texture and flavour compared with bio-yoghurt without additives and manufactured with adding TGase. So, this study recommended using inulin and lactulose for their functional properties to guarantee the existence of bifidobacteria with suitable counts in bio-yoghurt to gain its healthy benefits.

Viability of probiotic bacteria in fermented skim milk produced with different levels of milk powder and sugar

In this work, the effect of skim milk powder (0, 5%, 10%, 15% w/v) and sugar (0%, 10% w/v) on the viability of probiotic micro‐organisms and on the quality of fermented milks was investigated. Fermented milks were submitted to physicochemical, microbiological and sensory analyses on the 1st, 10th and 21st days after production. Sugar inclusion did not affect the probiotic growth in fermented milks, but milk powder levels of 10–15% influenced positively the probiotic counts, which were above six log colony‐forming units (cfu)/g. These findings can be useful for small dairy industries that are interested in producing flavoured fermented milks without decreasing the viability of probiotic micro‐organisms during its shelf life.

The Microstructure and Physicochemical Properties of Probiotic Buffalo Yoghurt During Fermentation and Storage: a Comparison with Bovine Yoghurt

The physicochemical and rheological properties of yoghurt made from unstandardised unhomogenised buffalo milk were investigated during fermentation and 28 days of storage and compared to the properties of yoghurt made from homogenised fortified bovine milk. A number of differences observed in the gel network can be linked to differences in milk composition. The microstructure of buffalo yoghurt, as assessed by confocal laser scanning microscopy (CLSM) and cryo scanning electron microscopy (cryo-SEM), was interrupted by large fat globules and featured more serum pores. These fat globules have a lower surface area and bind less protein than the homogenised fat globules in bovine milk. These microstructural differences likely lead to the higher syneresis observed for buffalo yoghurt with an increase from 17.4 % (w/w) to 19.7 % (w/w) in the weight of whey generated at days 1 and 28 of the storage. The higher concentration of total calcium in buffalo milk resulted in the release of more ionic calcium during fermentation. Gelation was also slower but the strength of the two gels was similar due to similar protein and total solids concentrations. Buffalo yoghurt was more viscous, less able to recover from deformation and less Newtonian than bovine yoghurt with a thixotropy of 3,035 Pa.s−1 measured for buffalo yoghurt at the end of the storage, at least four times higher than the thixotropy of bovine yoghurt. While the titratable acidity, lactose consumption and changes in organic acid concentrations were similar, differences were recorded in the viability of probiotic bacteria with a lower viability of Lactobacillus acidophilus of 5.17 log (CFU/g) recorded for buffalo yoghurt at day 28 of the storage. Our results show that factors other than the total solids content and protein concentration of milk affect the structural properties of yoghurt. They also illustrate the physicochemical reasons why buffalo and bovine yoghurt are reported to have different sensory properties and provide insight into how compositional changes can be used to alter the microstructure and properties of dairy products.

Erratum to: Effects of Chlorella vulgaris and Arthrospira platensis addition on viability of probiotic bacteria in yogurt and its biochemical properties

Erratum to: Effects of Chlorella vulgaris and Arthrospira platensis addition on viability of probiotic bacteria in yogurt and its biochemical properties

Effects of Chlorella vulgaris and Arthrospira platensis addition on viability of probiotic bacteria in yogurt and its biochemical properties

It is a practice to add microalgae into plain and probiotic fermented milks in order to promote the functionality of these products via their direct health effects as well as the enhancing impact on viability of probiotic microorganisms in product and in gastrointestinal tract. In this study, the effects of addition of two species of microalgae including Arthrospira platensis and Chlorella vulgaris (seven yogurt treatments containing three concentrations for each microalgae—0.25, 0.50, and 1.00 %—and a control without microalgae) on pH, titrable acidity, and redox potential changes as well as on the viability of probiotic bacteria during fermentation and during a 28-day refrigerated storage period (5 °C) were investigated in yogurt. Also, the amounts of lactic and acetic acids at the end of fermentation were assessed. The culture composition of yogurt was ABY type, containing Lactobacillus acidophilus LA-5, Bifidobacterium lactis BB-12, Lactobacillus delbrueckii ssp. bulgaricus, and Stresptococcus themophilus. The addition of microalgae significantly (p < 0.05) increased the viability of L. acidophilus and bifdobacteria at the end of fermentation and during the storage period. Treatments containing A. platensis had slower pH decline, faster acidity increase, longer incubation time, and greater final titrable acidity than those containing C. vulgaris and control. In treatments containing 0.5 or 1 % microalgae, the viability was almost higher than 107 cfu/mL until the end of refrigerated storage.

Functional foods as carriers for SYNBIO®, a probiotic bacteria combination

The popularity of functional foods continues to increase as consumers desire flavorful foods that will fulfil their health needs. Among these foods, probiotics may exert positive effects on the composition of gut microbiota and overall health. However, in order to be beneficial, the bacterial cultures have to remain live and active at the time of consumption. The aim of this study was to develop new probiotic food products, such as seasoned cheeses, salami, chocolate and ice-cream with a final probiotic concentration of approximately 109CFU/daily dose of Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® mixed 1:1 (SYNBIO®). The survival and viability of probiotics were determined during the foods shelf-life. The values of viable probiotic bacteria of all dairy and non-dairy foods were between 107 and 109CFU/g of food at the end of the shelf-life and for some of them the values were maintained even after the expiry date. Based on the results of the current study, all the dairy (“Caciotta” cheese, “Pecorino” cheese, “Büscion” Swiss cheese and “Fiordilatte” ice-cream) and non-dairy (“Ciauscolo” salami, Larded salami, Swiss small salami, milk chocolate, dark chocolate, organic jam and chocolate mousse) food products studied would be excellent vehicles to deliver the probiotic health effects because of the high viability of probiotics during the shelf-life of foods and in some cases even after their expiry date.

Effect of Cold Storage on Viability of Probiotic Bacteria in Carrot Fortified Milk

The growing interest in new functional drinks, resulting to the development of nutritionally and healthy probiotic drinks for consumers. Since dairy based products are a good carrier for probiotics, the suitability of milk/carrot juice drink stored at 4 ± 2°C for up to 20 days for the production of non-fermented probiotic drink was studied and survival of lactobacillus acidophilus LA5, lactobacillus plantarum, lactobacillus rhamnosus GG and bifidobacterium lactis BB12 was evaluated. The samples were evaluated in 5 days interval for cell number, pH and acidity. L.acidophilus LA5 seemed more stable than three other strains in this medium with more than 98% viability during storage but other strains showed a less viability between 88-92%. The pH and acidity changes by L.acidophilus LA5, L.Plantarum and B.lactis BB12 in storage time were low and varied according to strain from 6.43 to 6.66 and 0.13% to 0.15% (according to lactic acid) respectively and the means comparision did not show any significant differences between them. The L.rhamnosus GG and control (non-probiotic) samples showed more variation in pH and acidity. Changes of pH and acidity by L.rhamnosus varied significantly from 5.33-6.47 and 0.13-0.31% respectively. The pH level decreased from 6.48 to 5.85 and the acidity increased from 0.13% to 0.28% in the control sample. The outcome of the overall study points that milk/carrot juice drink could serve as a probiotic drink after refrigerated storage for 20 days.

Screening of Lactobacillus spp. from Buffalo Yoghurt for Probiotic and Antibacterial Activity

Since the beneficial effects of viable probiotic bacteria as dietary supplements have gained huge research interest, Lactobacillus spp. with probiotic characteristics are widely used to prepare fermented dairy products such as yoghurts, milk-shakes etc. In this study, eight (08) homemade yoghurt samples were collected from different regions in the country for isolation of probiotic Lactobacillus spp. Among the samples, four (04) isolates were identified as Lactobacillus plantarum based on their growth and biochemical characteristics. The Isolates were resistant to NaCl (1-9%) and bilesalt (0.05-0.3%) and showed good growth in the acidic condition, while maximum growth was observed at pH around 6.0. The isolates were examined for their antibacterial activity against nine (09) different test pathogens and found all pathogens are inhibited their growth to some extent but maximum zone of inhibition was observed against Bacillus cereus (53.20 mm) and minimum was against Staphylococcus aureus (19 mm) after 72 hour incubation. The results of the present study indicate that, homemade yoghurts in Bangladesh are potential source of probiotic Lactobacillus spp. Further extensive research on isolation and characterization of probiotic organisms from local fermented foods and their growth optimization might be required for development of probiotic enriched food supplements in our country.

Quantification of viable spray-dried potential probiotic lactobacilli using real-time PCR

The basic requirement for probiotic bacteria to be able to perform expected positive effects is to be alive. Therefore, appropriate quantification methods are crucial. Bacterial quantification based on nucleic acid detection is increasingly used. Spray-drying (SD) is one of the possibilities to improve the survival of probiotic bacteria against negative environmental effects. The aim of this study was to investigate the survival of spray-dried Lactobacillus plantarum 564 and Lactobacillus paracasei Z-8, and to investigate the impact on some probiotic properties caused by SD of both tested strains. Besides the plate count technique, the aim was to examine the possibility of using propidium monoazide (PMA) in combination with real-time polymerase chain reaction (PCR) for determining spray-dried tested strains. The number of intact cells, Lb. plantarum 564 and Lb. paracasei Z-8, was determined by real-time PCR with PMA, and it was similar to the number of investigated strains obtained by the plate count method. Spray-dried Lb. plantarum 564 and Lb. paracasei Z-8 demonstrated very good probiotic ability. It may be concluded that the PMA real-time PCR determination of the viability of probiotic bacteria could complement the plate count method and SD may be a cost-effective way to produce large quantities of some probiotic cultures.

Viability of the probiotic bacteria L. acidophilus in dairy products

A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus. Because of the potential health benefits, these organisms are increasingly incorporated into dairy foods. Viability of probiotic bacteria is important in order to provide health benefits. However, many studies have shown low viability of probiotics in market preparations. This study cover selective enumeration and survival of probiotic bacteria L. acidophilus in some dairy drinks. L. acidophilus was found in the range from 106 to 107 CFU.g-1 in five types of fermented milk products containing probiotic cultures. Two investigated products were up to standard according to Regulation of Ministry of Agriculture and Ministry of Health of Slovak Republic.

Utilization of Makgeolli sludge for growth of probiotic bacteria

A number of health benefits have been claimed for probiotic bacteria such as Bifidobacterium (B) spp. Lactobacillus(L) acidophilus, and Lactococcus(Lc) cremoris. Viability of probiotic bacteria is important in order to provide health benefits. Only a limited culture media for the test purpose of probiotic bacteria are commercially available (MRS broth), but the media for large-scale propagation of viable cells which are able to be used as food additive are not available. The manufacture of a low priced and preferred novel medium for probiotic bacteria was therefore, attempted using whey protein concentrate(WPC) and Makgeolli sludge as a starting material. The effect of WPC and Makgeolli sludge on the growth of four strains (B. bifidum 15696, B. longum 15707, L. acidophilus CH-2, and Lc. cremoris 20076) was investigated. Medium prepared such as WPC, Makgeolli sludge, and WPC+Makgeolli sludge(WPCMs). It was observed that the growth of 4 strains (B. bifidum 15696, B. longum 15707, L. acidophilus CH-2, and Lc. cremoris 20076) was stimulated by Makgeolli sludge, WPC, WPCMs. Especially, Viable cell number of 4 strains in the WPCMs were higher than that of the single media. These result suggest the possibility that Makgeolli and WPC, acts as a growth factor for the growth of probiotic bacteria.

The influence of different combinations of probiotic bacteria and fermentation temperatures on the microbiological and physicochemical characteristics of fermented lactic beverages containing soybean hydrosoluble extract during refrigerated storage

Lactic beverages containing probiotics were prepared with whole UHT milk, whey of Mozzarella cheese, soybean hydrosoluble extract and sugar. Three formulations were studied, each one containing a different combination of probiotic/starter bacteria, fermented at two different temperatures (37 and 45 °C). The aim of this work was to verify the influence of these variables on the viability of probiotic microorganisms and on the physicochemical stability of lactic beverages during storage under refrigeration (21 days at 7 °C). The results indicated that the fermentation temperature had a significant effect on the viability of probiotic bacteria. Counts for Lactobacillus acidophilus were affected by storage time, resulting appropriate after 21 days only for the beverage fermented at 37 °C. Physicochemical parameters did not exhibit drastic variations - proving the stability of formulations during storage. Cells of Bifidobacterium spp. showed high survival ability, probably due to the presence of growth promoters from soybean and cheese whey. The fermentation temperature of 37 °C allowed counts above the minimum limit for all the studied microorganisms, being preferred to the temperature of 45 °C. The inclusion of soybean hydrosoluble extract, a prebiotics source, resulted in a symbiotic product with more benefits to the health of consumers.

Viability of Bifidobacterium longum in cheddar cheese curd during manufacture and storage: effect of microencapsulation and point of inoculation

The goal of this study was to assess the effect of methods of inoculation on the viability of probiotic bacteria during cheddar cheese manufacture as well as their stability during storage. Bifidobacterium longum ATCC 15708 was freeze-dried and microencapsulated by spray-coating. The effect of inoculation of free whole cell or microencapsulated cells at three points during manufacture (milk before renneting, at cheddaring or at salting) on the viable counts in cheese and whey was investigated. Microencapsulation had no effect on viable counts, chemical parameters (lactose, lactic acid, total nitrogen, nitrogen soluble in TCA, moisture) or sensory properties during manufacturing or storage of the fresh cheeses for 14 days. Inoculation of the bifidobacteria in milk before renneting resulted in higher viable counts in comparison to other points of inoculation. Bifidobacteria added at the salting step, which survived pressing, were subsequently more stable during storage than those inoculated in milk. The stability of B. longum 15708 during storage was greater in the pressed cheeses that in the free curds. The results of this study provides technological data for cheese makers on the optimum point of inoculation as well as the benefit of pressing the curds in order to ensure high levels of probiotics in fresh cheddar cheese.

Effect of germination and probiotic fermentation on nutrient profile of pearl millet based food blends

PurposeProbiotic fermented foods are fast being recognized as health foods. Most of such foods are based on dairy products but little research work is available on coarse cereals and millets, which constitute the staple foods in developing countries. This paper aims to determine the effect of germination and fementation on nutrient composition of pearl millet based food blends.Design/methodology/approachIndigenously developed pearl millet based food blends containing raw and germinated pearl millet flour, whey powder and tomato pulp (2:1:1w/w) were autoclaved, cooled and fermented with 5 percent Lactobacillus acidophilus curd which supplied 106cells/ml to the slurry at 37°C for 12 h. The unfermented blends, after autoclaving, served as controls. The developed food blends were subjected to nutritional evaluation by using the standard methods of analysis. The data were statistically analysed.FindingsPearl millet based, germinated, autoclaved and fermented, food blend maintained adequate cell viability (8.64 cfu g‐1) as compared to non‐germinated food blend. Germination and probiotic fermentation caused significant improvement in the contents of thiamine, niacin, total lysine, protein fractions, sugars, soluble dietary fibre and in vitro availability of Ca, Fe and Zn of food blends.Practical implicationsResearch is currently aimed at developing probiotic millet based food mixture, which had enhanced nutrient profile. Hence, it can be considered for commercialization after establishing its health/therapeutic implications among the population.Originality/valueDairy foods have preferentially been used as the carrier medium for probiotics. This paper explores the possibility of using staple foods as the carrier medium. The consumption of such food mixtures containing viable probiotic bacteria should be enhanced among consumers in term of their role in health maintenance and disease prevention.

Probiotic ice cream: viability of probiotic bacteria and sensory properties

Ice cream is a dairy product with good potential to act as a food carrier for probiotic bacteria. The incorporation of probiotic bacteria into ice cream is highly advantageous since, in addition to making a functional healthy food, ice cream in itself contains beneficial substances such as dairy raw materials, vitamins and minerals, and is consumed by the general population. Also, compared with fermented milks as a vehicle, ice cream supports considerably greater viability of probiotic strains during production and especially storage. However, losses in the viability of probiotic bacteria in ice cream unavoidably occur during product formulation, processing, storage and melting. During these stages, probiotic cells are subjected to different stresses related to pH, acidity, redox potential, freezing, oxygen (especially in overrun processing), sugar concentration and osmotic effects, hydrogen peroxide, antagonistic impact of co-cultures (in fermented ice creams), and mechanical shearing. It seems that the rate of loss of probiotic cells is greater during the freezing process than during storage. Practicing methods such as selection and application of oxygen-resistant probiotic strains, elimination of molecular oxygen (using oxygen-scavenging components, packaging material that is impermeable to oxygen as well as thicker packaging materials and active packaging systems), applying severe heat treatment, using microencapsulation techniques, and adjusting the product formulation (e.g., fortification of milk with nutrients and prebiotics) can increase the viability of probiotics in the final product. Supplementation of ice cream with probiotic bacteria has been found to have little effect on its flavor, texture or other sensory characteristics. There are also many ways to improve the sensory attributes of the product to compensate for any changes that do occur. This article reviews the viability of probiotic bacteria in ice cream and the main methods used to improve their viability and the sensory characteristics of probiotic ice cream.

On the viability of five probiotic strains when immobilised on various polymers

The viability of probiotic bacteria in six food‐grade polymers, at two concentrations, was evaluated in order to predict their feasibility as materials for bacterium immobilisation. Alginate and whey proteins were the most adequate polymers, except for Lactobacillus acidophilus Ki and Lactobacillus casei 01 at 2% (m/v) alginate. Xanthan gum appeared to be a potential vector for three strains. L‐carrageenan was adequate for both Bifidobacterium strains, but not for Lactobacillus at 2% (m/v). Bifidobacterium strains were not negatively affected by cellulose acetate phthalate, while the opposite held for L. acidophilus strains. Chitosan was the poorest polymer for immobilisation of probiotic bacteria.

Viability of probiotic bacteria in maple sap products under storage and gastrointestinal conditions

This study was undertaken to develop new probiotic products based on liquid maple sap or its concentrate. Sap and concentrate, with or without inulin (2%) were inoculated with Bifidobacterium lactis Bb12 and Lactobacillus rhamnosus GG valio at initial counts of 10 7–10 8 CFU/ml. Viability was assessed over four weeks of storage at 4 °C and under in vitro simulated gastrointestinal conditions using dynamic gastrointestinal model known as TIM-1. Viability was maintained throughout the storage period at the same order of 10 7 to 10 8 CFU/ml. Inulin significantly enhanced the survivability during passage through the gastrointestinal tract simulator. The developed products could be an excellent alternative for delivering probiotics, especially for individuals suffering from lactose intolerance to dairy products.