The aim of this study was to develop simple, rapid and reliable methods for the selective determination of
from ACTIVIA (Danone) yogurts. The methods are based on a modified MRS medium (B-broth), which does not contain inhibitory additives. The sugar source of the medium is maltose, which is metabolized by the bifidobacteria applied in the probiotic products, and not by the normal microflora of yogurt (
). The redox potential of the medium was reduced with cysteine-HCl. Due to its reduced redox potential, the new bouillon is suitable for aerobic cultivation of bifidobacteria, while in agar form it needs anaerobic incubation. In bouillon form (MPN method) the incubation time is only 2 days compared to the 5-day requirement of the classical anaerobic plate counting methods. The B-broth in diluted form was successfully used in a RABIT (Don Whitley) equipment for selective impedimetric determination of bifidobacteria in Danone yogurts. The exact detection time of the
counts in a good quality probiotic yogurt, containing bifidobacteria at a concentration of 10
is not more than 10 to 12 h (in contrast to the 5 days of classical anaerobic plate counting methods).
The purpose of this research was to monitor the changes during storage in survival of bifidobacteria in a soft-frozen ice cream supplemented with a yeast cell wall-based product claimed to contribute to the functioning of the immune system. An ice cream mix was prepared and pasteurised. After overnight aging at 4 °C, it was inoculated with Bifidobacterium animalis subsp. lactis Bb-12. Two batches of the mix were supplemented with a commercial Saccharomyces cerevisiae cell wall product at 2.0% and 4.0% (w/w), whereas a third batch was left unsupplemented and served as control. The final mixes were frozen, and the three products were stored at –13 °C for 7 days. The ice creams contained viable bifidobacteria cells at levels exceeding 106 CFU g–1 throughout the storage throughout the storage period. Although the yeast supplement decreased the loss of viability of bifidobacteria during frozen storage of ice creams, it imparted a slightly bitter off-flavour to the samples and it also negatively influenced the original white colour of the product, thereby necessitating further work to develop flavoured varieties of the Saccharomyces cell wall-containing synbiotic ice cream.
B ujna , E. , F arkas , N.A. , T ran , A.M. , D am , M.S. & N guyen , Q.D. ( 2018 ): Lactic acid fermentation of apricot juice by mono- and mixed cultures of probiotic Lactobacillus and Bifidobacterium strains . Food Sci. Biotechnol
The inhibitory effects of three berberine alkaloids (BAs) from Coptis chinensis Franch on Bifidobacterium adolescentis growth were investigated by microcalorimetry. The growth rate constant (k) and maximum heat-output power (Pmax) decreased and peak time of maximum heat-output power (tp) prolonged with the increase of BAs concentration. Half inhibitory ratios (IC50) BAs were respectively 790.3 (berberine),
339.6 (coptisine) and 229.8 μL−1 (palmatine), which indicated the sequence of their antimicrobial activity: berberine<coptisine<palmatine. Combined with previous
findings, the sequence which could show the bioactivity of Bacillus shigae and Escherichia coli was: berberine>coptisine>palmatine. The structure-function relationship of BAs indicated that the functional group methylenedioxy
or methoxyl at C2 and C3 might be the major group inducing the activities of BAs on E. coli and B. adolescentis. Meanwhile, the substituent groups at C2, C3, C9 and C10 almost had equal effect on B. shigae.
This study was carried out to determine the intensity of production of acetic acid, short (SCFA) and medium (MCFA) chain fatty acids in cow and goat milk fermented by the use of Bifidobacterium longum Bb-46. Amounts of SCFA and MCFA in fermented goat and cow milk were determined by the use of GC/FID method. Concentration of acetic acid in the samples of fermented goat and cow milk were measured using GC/MS method. Furthermore, the growth rates of Bifidobacterium longum Bb-46 and its fermentation activity in goat and cow milk were also determined. Obtained results suggest higher metabolic activity of Bifidobacterium longum Bb-46 in goat than in cow milk. Bifidobacterium longum Bb-46 grew better in goat than in cow milk. Consequently, pH values decreased more rapidly during the fermentation of goat milk. Contents of all the examined SCFA and MCFA, as well as of acetic acid, increased more rapidly in goat milk during the whole fermentation process.
The present study was to evaluate the survival rate of free and encapsulated Bifidobacterium bifidum BB28 under simulated gastrointestinal conditions and its stability during storage. Results showed that non-microencapsulated Bifidobacterium bifidum BB28 was more susceptible to simulated gastrointestinal conditions than microencapsulated bacteria. Microencapsulated Bifidobacterium BB28 exhibited a lower population reduction than free cells during exposure to simulated gastrointestinal conditions, the viable count of monolayer microcapsules, double layer microcapsules, and triple layer microcapsules decreased by nine magnitudes, four magnitudes, and one magnitude after 2 h, respectively. The enteric test showed that the microorganism cells were released from the monolayer, double layer, and triple layer microcapsules completely in 40 min. Moreover, the optimum storage times of free Bifidobacterium BB28, monolayer microcapsules, double layer microcapsules, and triple layer microcapsules were 21 days, 21 days, 28 days, and more than 35 days in orange juice, pure milk, and nutrition Express (a commercially available milk based drink), and the viable counts were maintained at 1×106 CFU g−1 or more, which means that the double layer and triple layer of microcapsules of B. bifidum BB28 have great potential in food application.
The effect of three individual strains of Lactobacillus (L. acidophilus NCC 12, L. acidophilus NCC 36, L. acidophilus NCC 68)and two Bifidobacterium strains (B. bifidum Bb13, B. bifidum NCC 381) on the growth and AFB1 production of Aspergillus flavus NRRL 2999 was determined. The commercial MRS broth and skim milk medium were used to determine the effect of tested bacteria on the growth and AFB1 production of A. flavus NRRL 2999. The bacteria were not effective in preventing the growth of A. flavus NRRL 2999 both in MRS broth and skim milk. However, higher levels of AFB1 were obtained in the presence of individual strains of Lactobacillus and Bifidobacterium. The greatest difference was observed in the AFB1 production of A. flavus NRRL 2999 in skim milk medium compared with MRS broth.
The aim of this study was to determine the influence of goat’s milk fermented by
Bb-46 on pathogenic
strain, as well as to determine the differences of inhibitory potential between fermented goat’s and cow’s milk. The results showed significantly higher inhibitory effect of fermented goat’s milk on the growth of
compared to that of fermented cow’s milk. Fermented goat’s milk inhibited the growth of
during the whole fermentation period. In contrast to fermented goat’s milk, weaker inhibitory effect of fermented cow’s milk was observed only during the first phase of fermentation (incompletely fermented samples with higher pH values and lower number of viable cells of
Bb-46). The obtained results suggested that there was no correlation between changes of pH or CFU of
Bb-46 during fermentation and the inhibitory effect of fermented cow’s and goat’s milk. However, the results suggested some correlation between the inhibition of
growth and the content of SCFA and MCFA in fermented cow’s milk. At the same time, considerably higher amounts of all examined SCFA and MCFA were produced in goat’s milk in all the phases of the fermentation process.
Sensory acceptance of four trials of probiotic petit-suisse cheese was investigated. Cheeses were prepared using
TA 040 as starter not supplemented with any probiotic culture (T1-control),
BL04 (T3) and
(T4). Sensory acceptance tests were performed after 7 and 14 days of storage at 4±1 °C, using a 9-point hedonic scale to evaluate flavour, texture and overall acceptability. The population of La-5 and BL04 remained at 7.0 log CFU g
and at 8.0 log CFU g-1, respectively, during storage for up to 28 days. After 7 and 14 days of storage, cheese T4 presented the highest sensory acceptance for all attributes evaluated and differed significantly from the other cheeses (P<0.05). After 14 days of storage, cheese T3 presented the lowest acceptance and differed significantly from the other cheeses (P<0.05). The supplementation of petit-suisse cheese T4 with both La-5 and BL04 in coculture with a starter culture resulted in a product with high probiotic populations during storage and excellent sensory acceptance. The results also showed that, when added separately, La-5 and BL04 did not affect the sensory acceptability of petit-suisse cheese.