Probiotic Fermented Milk Research Articles

New functional milk-based products in the Italian market

The aim of this study is to obtain an overview, from a chemical and a nutritional point of view, of functional products such as lactose-hydrolysed milk, milk with added probiotics, prebiotics and vitamins, probiotic fermented milk, and synbiotic fermented milk. For this purpose, six samples of lactose-hydrolysed UHT milk and two samples of milk with added functional ingredients, seven probiotic and four synbiotic fermented milk samples, have been studied. In lactose-hydrolysed milk samples, proximate composition, vitamins A, E and cholesterol contents have not shown significant differences, with the obvious exception of a skimmed milk sample containing small amounts of fat and related compounds. The other samples have shown a large compositional variability, and, in particular, cholesterol ranged from 3.6 to 12.7 mg/100 g, vitamin E ranged from 2.1 to 3300 μg/100 g and vitamin A ranged from 3.5 to 182.0 Retinol Equivalents (μg/100 g). Lactose levels ranged from 0.26 to 0.77 g/100 g in lactose-hydrolysed milk samples and from 2.32 to 4.55 g/100 g in the other milk samples.

Influence of chicory inulin on the survival of microbiota of a probiotic fermented milk during refrigerated storage

Inulin-supplemented and control probiotic fermented milks were produced using a dairy starter culture containingsStreptococcus thermophilus CHCC 742/2130,Lactobacillus acidophilus La-5 andBifidobacterium lactis Bb-12, and were then stored at 4°C for 6 weeks. Microbiological analyses were performed at weekly intervals. The results showed that the presence of inulin at 1 t o 5% (wt/v) did not influence significantly (P>0.05) the survival rates of eitherS. thermophilus orL. acidophilus. However, the addition of inulin at 5% (wt/v) had a significant beneficial effect (P<0.05) on the viability of bifidobacteria after 28 days of refrigerated storage.

The Effects of a Probiotic Milk Product Containing &lt;i&gt;Lactobacillus casei&lt;/i&gt; Strain Shirota on the Defecation Frequency and the Intestinal Microflora of Sub-optimal Health State Volunteers: A Randomized Placebo-controlled Cross-over Study

Forty healthy individuals with a low defecation frequency were selected, and the effects of intake of a fermented milk beverage that contains Lactobacillus casei strain Shirota (LcS) at 4 x 10 9 bacteria/bottle for 2 weeks (1 bottle/day) on the defecation frequency and intestinal microflora were evaluated by the placebo-controlled double-blind cross-over scheme. Defecation frequency both in times per week and days per week significantly increased in the LcS beverage period compared with the frequency before the beginning of intake. The differences were more notable in those with a stronger tendency to constipation (frequency of defecation before intake ≤ 4.0 times/week, n=21), and the frequency of defecation in the LcS beverage period was significantly higher than in the placebo period. The stool smell and feeling of completion of voiding improved significantly in the LcS beverage period compared with the placebo period, and in those with a stronger tendency to constipation, the stools were significantly softened compared with the state before intake. The number of bifidobacteria and their percentage in the total number of fecal bacteria in the LcS beverage period increased significantly compared with the levels before intake and were significantly higher than the values in the placebo period. No marked change due to the intake of the LcS beverage was observed in the other components of the microflora, the organic acid contents, stool pH, water content, or contents of putrefactive metabolites. These results suggest that intake of the probiotic fermented milk beverage conditions the intestines by improving the state of bowel movements and stool quality and increasing the fecal population level of bifidobacteria.

Influence of addition of raffinose family oligosaccharides on probiotic survival in fermented milk during refrigerated storage

The influence of the addition of raffinose family oligosaccharides (RFOs) extracted from lupin seeds on the survival of Bifidobacterium lactis Bb-12 and Lactobacillus acidophilus La-5 in fermented milk during 21 days of storage in refrigerated conditions was studied. For this purpose, viability and metabolic activity (expressed as pH, lactic and acetic acid production and utilization of soluble carbohydrates) of probiotic bacteria were determined. Retention of viability of B. lactis Bb-12 and L. acidophilus La-5 was greater in fermented milk with RFOs. The pH of probiotic fermented milk at 21 days of storage was lower (4.27) compared with probiotic fermented milk with RFOs (4.37). The highest levels of lactic and acetic acid were produced in probiotic fermented milk without RFOs compared with probiotic fermented milk with RFOs during storage at 4 °C. Soluble carbohydrates were utilised in fermented milk with and without RFOs, respectively, for maintaining B. lactis Bb-12 and L. acidophilus populations during refrigerated storage. In conclusion, all these experiments provide convincing evidence that RFOs have beneficial effects on the survival of these probiotic cultures in dairy products. As a result, such stored dairy products containing both probiotics and prebiotics have synergistic actions in the promotion of health.

Raffinose Family of Oligosaccharides from Lupin Seeds as Prebiotics: Application in Dairy Products

The raffinose family of oligosaccharides (RFOs) isolated from lupin seeds (Lupinus albus var. Multolupa) was evaluated for bifidogenic effects during the manufacture of probiotic fermented milk. A mixed starter inoculum was composed of Bifidobacterium lactis Bb-12 and Lactobacillus acidophilus (1:1). Lupins are a rich source of RFOs that can be used as functional food ingredients. The addition of RFOs to milk increased B. lactis Bb-12 and L. acidophilus populations at the final fermentation time compared with controls. Final fermentation products are positively affected by addition of RFOs, and time of fermentation was reduced from 12 to 10 h. When RFOs were added to milk, they were preferentially used as a carbon source (57.7%) compared with lactose (23.7%) at the end of fermentation. These results suggest that the eventual choice of B. lactis Bb-12 and L. acidophilus in a mixed culture at a 1:1 ratio and addition of RFOs to produce a fermented milk product would have the advantages of rapid growth and acidification rate and would likely increase the probiotic effect of the final functional product.

Lactobacillus casei cell immobilization on fruit pieces for probiotic additive, fermented milk and lactic acid production

Lactobacillus casei cells were immobilized on fruit (apple and quince) pieces separately and the immobilized biocatalysts were used for 15 successive fermentation batches of whey immediately after their preparation and for fermentations of milk immediately after their preparation and after a long storage period at low temperature. The immobilized biocatalysts used for successive fermentation batches of whey proved to be very effective and suitable for food grade lactic acid production, while no loss of activity at all temperatures (30, 37, 45 °C) tested was observed, as very high lactose conversion was reported. Cell immobilization of L. casei on apple and quince pieces was also shown by electron microscopy. In addition, apple and quince supported biocatalysts were used for milk fermentation immediately after their preparation, and after storage for 15, 98, and 129 days at 4 °C. No infection was reported during the storage periods. After storage, the immobilized biocatalysts were reactivated very quickly and produced milk fermentation products with a fruity, distinctive aroma which remained during all storage period.

Assessment of novel probiotic Lactobacillus casei strains for the production of functional dairy foods

Selected Lactobacillus casei strains were examined for their potential use in new probiotic fermented milks by evaluation of their technological performances, in vitro adhesion capacity and intestinal transit tolerance after administration to rats. Serum, tissue and faecal samples were analysed before and during treatments. The number of intestinal lactobacilli increased significantly after administration of all four strains as verified by standard microbiological analysis and specific polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). Lactobacillus casei strains were also detected by PCR in faecal samples and specimens of the intestinal epithelium after treatment. Electron microscopy of gut mucosa revealed a thickening of the glycocalyx covering the enterocytes. In all treated rats, levels of serum triglycerides, cholesterol, transaminase and total bilirubin decreased. Microbiological and haematological parameters indicated that all four L. casei strains present favourable strain-specific properties for their utilisation in functional, health-favouring food.

Effect of Fermented Milk Containing &lt;i&gt;Lactobacillus johnsonii&lt;/i&gt; La1 (LC1&lt;sub&gt;®&lt;/sub&gt;) on Defecation in Healthy Japanese Adults—A Double Blind Placebo Controlled Study—

To elucidate the effect of fermented milk containing Lactobacillus johnsonii Lal (LC1®) on defecation, a double blind placebo controlled study was conducted. Healthy Japanese adults (24-67 years of age, n = 57, male: 31,female: 26) were randomly divided into two groups, and the subjects in the LC1 group (n = 30) consumed LC1 fermented milk containing L. johnsonii Lal at 1 x 10 9 cfu/90 g (90 g per day) for 21 days and the subjects in the control group (n = 27) consumed placebo fermented milk without the Lal strain in the same manner. In the subjects of the LC1 group with mild constipation (n = 9), less than one defecation per day in the 3 weeks observation period, defecation frequency both in times per week and days per week significantly increased during consumption of LC1 compared to before consumption (p < 0.05), and the frequency recovered to normal status with at least one defecation per day in 4 out of 9 of subjects (44%) after 3 weeks LC1 consumption. Subjects with mild constipation in the control group (n = 7) showed no significant changes in defecation frequency. The frequency in the subjects with normal defecation did not change in either group. L. johnsonii Lal was found in all feces from 10 subjects in the LC1 group participating in fecal collection, suggesting that Lal strain efficiently reached the gastrointestinal tract as a viable form. Excess amount (360 g per day) of LC1 intake for 2 weeks in the other healthy subjects (n = 10) caused an increase in defecation frequency, which was kept at the normal level of less than twice per day. These results suggest that LC1®, a probiotic fermented milk containing L. johnsonii Lal, is beneficial for improving mild constipation without any safety concerns.

Caseinomacropeptide and whey protein concentrate enhance Bifidobacterium lactis growth in milk

Caseinomacropeptide (CMP), isolated from cow’s or combined ewe’s and goat’s sweet cheese whey, and whey protein concentrate (WPC), enhanced growth of Bifidobacterium lactis in milk. Supplementation of milk at 2% CMP increased counts of B. lactis by 1.5 log cycles after 24 h incubation at 37 °C when compared with unsupplemented milk, showing no differences between the two CMPs. The highest bacterial growth (9.1 log cfu ml −1) was obtained when milk was supplemented with 2% WPC. The growth-promoting activity shown by WPC could be due to its CMP and whey protein content. CMP and WPC could be utilised to complement milk in order to increase counts of bifidobacteria in probiotic fermented milks.

Antioxidative probiotic fermented goats' milk decreases oxidative stress-mediated atherogenicity in human subjects.

The increasing interest in a healthy diet is stimulating innovative development of novel scientific products in the food industry. The viable lactic acid bacteria in fermented milk products, such as yoghurt, have been associated with increased lactose tolerance, a well-balanced intestinal microflora, antimicrobial activity, stimulation of the immune system and antitumoural, anticholesterolaemic and antioxidative properties in human subjects. Recently, we have studied a human Lactobacillus spp. strain that possesses antioxidative activity. The aim of the present pilot study was to develop goats' milk fermented with the human antioxidative lactobacilli strain, Lactobacillus fermentum ME-3, and to test the effect of the fermented probiotic goats' milk on oxidative stress markers (including markers for atherosclerosis) in human blood and urine and on the gut microflora. Twenty-one healthy subjects were assigned to two treatment groups: goats' milk group and fermented goats' milk group (150 g/d) for a period of 21 d. Consumption of fermented goats' milk improved anti-atherogenicity in healthy subjects: it prolonged resistance of the lipoprotein fraction to oxidation, lowered levels of peroxidized lipoproteins, oxidized LDL, 8-isoprostanes and glutathione redox ratio, and enhanced total antioxidative activity. The consumption of fermented goats' milk also altered both the prevalence and proportion of lactic acid bacteria species in the gut microflora of the subjects. We conclude that the goats' milk fermented with our special antioxidative lactobacilli strain Lactobacillus fermentum ME-3 exhibits anti-atherogenic effects.

Rheology and sensory profiling of set‐type fermented milks made with different commercial probiotic and yoghurt starter cultures

Varieties of set‐type probiotic fermented milks and yoghurt were made from recombined skimmed milk powder, anhydrous milk fat and commercial starter cultures (direct‐to‐vat inoculation, DVI). Serum separation of fermented milks and yoghurt with high initial rates of syneresis proceeded more slowly than separation of those with low initial rates of syneresis; the decrease during the storage period was linear and the rate of decrease was dependent on the type of starter culture used. The firmness of these products increased over the time period, and the rate of increase was linear and independent of the starter culture. The production of exopolysaccharide material by the starter microflora also influenced syneresis and firmness of the probiotic fermented milks. The average profiles of organic acids of all the products were similar with the exception of two starter cultures that generated the highest level of acetic acid. After cross‐validation, classification of the starter type using the organic acids values correctly predicted the type of starter culture used for 23 out of 24 samples. All the sensory attributes were influenced by the type of starter culture used and the trial, with the exception of viscosity character; acetic acid production by the microbial species of the starter cultures had the greatest influence on the flavour attribute.

Modelling of rheological, microbiological and acidification properties of a fermented milk product containing a probiotic strain of Lactobacillus paracasei

Abstract The simultaneous effect of fermentation temperature (FT, 36.7–43.4°C), milk total solid level (TS, 11.3–14.7%, w/v) and total inoculum concentration (TI, 2.16–3.84 v/v) on the acidification process and the rheological properties of fermented milk products with Lactobacillus paracasei ssp paracasei B117, Lactobacillus delbrueckii ssp bulgaricus Y 6.15 and Streptococcus thermophilus Y 4.10 was explored by means of response surface methodology. Maximum storage modulus (G′max), minimum loss tangent (tan δmin), rate of gelation (IE) and onset of gelation were the rheological parameters studied. Maximum acidification rate (Vm), time at which maximum acidification rate was observed (Tm), and time to reach the end of fermentation (Te) characterized the kinetics of acidification, whereas the increase in the number of the three bacteria at the end of fermentation was chosen as the microbiological parameter of the system. The growth/survival of microorganisms and the organic acid profile during cold storage as well as the overall product acceptability by a consumer panel were also assessed. TS strongly affected G′max and tan δmin; high TS resulted in large increase in G′max and decrease in tan δmin. Increasing fermentation temperature gave a decrease in the onset of gelation, Vm, Tm and Te, and an increase in the gelation rate (IE). Under conditions of relatively low FT (37–40°C), high TS (about 14%) and high TI (3–4%), relatively high gelation and low acidification rates were observed, fermentation took a longer time to finish, but the formed gels were firmer, showing higher G′max and lower tan δmin values. Low FT (36–38°C) enabled higher increase in the number of L. paracasei B 117. The probiotic strain showed good compatibility with the S. thermophilus Y 4.10 and L. bulgaricus Y 6.15, and satisfactory levels of all bacteria were found during fermentation and storage at 4°C for 21 days. No major differences in lactic and uric acid contents were seen between the control (probiotic strain-free product) and the probiotic fermented milk, whereas the latter contained slightly higher amounts of citric, pyruvic and orotic acids. Moreover, the probiotic fermented milk was graded by the consumer panel with a similar acceptability score as the control product.

Fermented milks: a historical food with modern applications--a review.

: This paper was presented at the symposium which was organized by Instituto Danone Mexico in May 2001, and it provides an overview of the current scientific knowledge on fermented milks concerning the historical developments, manufacturing stages, classification of such products, and nutritional aspects. Particular attention has been paid to the human health benefits associated with the consumption of these products, the use of probiotic starter cultures and their industrial applications, and the significance of using a trained sensory panel for the evaluation of probiotic fermented milks made with different commercial blends of starter cultures. The paper also highlights the future research areas for the exploitation of starter microflora (Lactobacillus, Bifidobacterium and Enterococcus species) in fermented milk products. : This review indicates that the complex metabolism of the starter cultures is well established; however, more information is still needed on specific microbial metabolites such as polymerization of milk sugars for the production of exopolysaccharides and the modification of the milk peptides and secretion of bacteriocins. More clinical studies are still required to establish the 'functional' health benefits of probiotic fermented milks to humans.

The effects of certain factors on the properties of yoghurt made from ewe’s milk

Standardized fat content (skimmed, 4.5 and 6.5%) ewe’s milk was used for production of yoghurt and probiotic-fermented milk. The yoghurt was made using a starter culture that consisted of Streptococcus ssp. thermophilus and Lactobacillus delbrueckii ssp. bulgaricus whilst, for the production of probiotic-fermented milk an ABT ( S. thermophilus, Lactobacillus acidophilus and Bifidobacterium ssp.) starter culture was used to inoculate the processed milk. All the products were analyzed when fresh and after 7 and 14 days of storage, for the determination of diacetyl, acetaldehyde and free fatty acid contents, as well as pH and titratable acidity. Sensory assessment and firmness of these products were also obtained. The type of starter culture used and the storage time influenced the overall properties of the yoghurt and probiotic-fermented milk products. The fat level in the ewe’s milk significantly influenced the free fatty acid content in the products.

Slovenian fermented milk with probiotics

The concept of functional foods and probiotics is a novelty in former Eastern block. The Croatian and Slovenian dairy industries are the first that launched probiotic. In this work, samples of probiotic fermented milks purchased from Slovenian market were stored within 25 days at three different temperatures (4° C, 20° C, 37° C), and changes in acetaldehyde, ethanol and diacetyl were determined. Above chemical compounds have a high impact on the desired product flavour. At the same time sensory evaluation was carried out. Acetaldehyde and ethanol concentration were determined by aldehyde dehydrogenase and alcohol dehydrogenase methods. Diacetyl was measured by modification of the Hill’s colorimetric method. Sensory analysis was conducted by five member panel, using a scoring system with weighted factors in the 20-point scale. The concentration of these flavour compounds changed during storage depending on duration and temperature in depot. Acetaldehyde content decreased at each temperature level during 25-days storage. Diacetyl and ethanol content increased with duration at all temperature levels. Sensoric quality decreased with duration and was closely related to changes in the content of aroma compounds. Changes of all investigated parameters were pronounced on higher temperature levels. Thus, there were no significant changes during the refrigerated storage at 4° C while at the other two temperature levels results pointed out significant differences between the values before and after storage.