Synbiotic potential of fresh cream cheese supplemented with inulin and Lactobacillus paracasei in co-culture with Streptococcus thermophilus

The influence of the addition of Lactobacillus paracasei and Streptococcus thermophilus on the fructan content at the beginning and at the end of storage at 4 ± 1 °C of a potentially synbiotic fresh cream cheese manufactured with inulin was investigated. Three cheese-making trials were prepared, all supplemented with a lactic culture of S. thermophilus (T1, T2 and T3). L. paracasei subsp. paracasei was added in T1 and T2. Inulin was added in T2 and the fructan content was measured after 1 and 21 days of storage. Samples of T2 possessed similar mean concentrations of fructans after 1 and 21 days of storage, 7.32% and 7.27%, respectively, and no significant difference was observed. These results indicated that the metabolism of starter and probiotic bacteria did not degrade the fructans present in those cheeses. Additionally, synbiotic cheeses possessed a fructan content higher than 7 g per 100 g, sufficient to confer prebiotic potential during the entire storage period of these products.     

Dried Tomato‐Flavored Probiotic Cream Cheese with Lactobacillus paracasei

Abstract: A dried tomato‐flavored probiotic cream cheese (P) containing Lactobacillus paracasei Lpc‐37 was developed for the purpose of this study. The same product, but without probiotic addition (C) was used as control. Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris were used as lactic starter cultures. Chemical composition analyses and sensory tests were performed on days 1 and 7, respectively. Titratable acidity, pH value and L. paracasei population were determined every 7 d during the refrigerated storage (21 d) of the cream cheeses. The experiment and analyses were performed in triplicate, using standard methods. Probiotic population remained greater than 10⁷ CFU/g throughout the storage period, thereby characterizing the product as potentially probiotic. Cream cheeses C and P did not differ on the sensory tests, both obtaining good overall acceptance by the consumers, of which 82.6% stated that they certainly or probably would buy the product. Practical Application: Lactobacillus paracasei Lpc‐37 is a probiotic bacterium and clinical studies have shown that this microorganism beneficially affects its host. In general, dried tomato‐flavored products and cream cheese are products with good acceptance by the consumers. Thus, regular consumption of the probiotic cream cheese developed in this study may have positive effects on health and well being of people if incorporated into their diet.     

Inulin and oligofructose improve sensory quality and increase the probiotic viable count in potentially synbiotic petit-suisse cheese

The influence of inulin, oligofructose and oligosaccharides from honey, combined in different proportions, on the consumers’ sensory acceptance, probiotic viable count and fructan content of novel potentially synbiotic petit-suisse cheeses was investigated. Probiotic populations varied from 7.20 up to 7.69 log cfu g⁻¹ (Bifidobacterium animalis subsp. lactis) and from 6.08 up to 6.99 log cfu g⁻¹ (Lactobacillus acidophilus). The highest fructan contents were achieved by the cheese trials containing oligofructose and/or inulin (above 8.90 g 100 g⁻¹). The control trial showed the lowest mean acceptance (6.63) after 28 days of refrigerated storage, whereas the highest acceptance (7.43) was observed for the trial containing 10 g 100 g⁻¹ oligofructose. Acceptance increased significantly during storage (P<0.05) only for cheeses supplemented with oligofructose and/or inulin. Cheeses containing honey did not perform well enough compared to the cheeses with addition of inulin and/or oligofructose, and the best synbiotic petit-suisse cheese considering sensory and technological functional features was that containing oligofructose and inulin combined, therefore encouraging the commercial product use.     

Sensory evaluation of probiotic Minas fresh cheese with Lactobacillus acidophilus added solely or in co-culture with a thermophilic starter culture

Sensory acceptance of formulations of probiotic Minas fresh cheese was investigated. Cheeses were prepared and supplemented with Lactobacillus acidophilus (T1 – probiotic), Lactobacillus acidophilus + Streptococcus thermophilus (T2 – probiotic + starter) or produced with no addition of cultures (T3 – control). Sensory acceptance tests were performed after 7 and 14 days of storage at 5 °C, using a 9‐point hedonic scale (1 = dislike extremely; 9 = like extremely). After 7 days, no significant difference was detected among cheeses T1, T2 and T3 (P > 0.05). After 14 days, cheeses T1 and T2 presented higher acceptance and differed significantly from cheeses T3. Cheeses T3 presented significant difference between 7 and 14 days of storage (P < 0.05), whereas probiotic cheeses T1 and T2 were stable in the same period (P > 0.05). The addition of L. acidophilus, either solely or in co‐culture with a thermophilic starter culture, resulted in good acceptance of Minas fresh cheese, improving sensory performance of the product during storage.     

Manufacture of Fior di Latte cheese by incorporation of probiotic lactobacilli

This work aimed to select heat-resistant probiotic lactobacilli to be added to Fior di Latte (high-moisture cow milk Mozzarella) cheese. First, 18 probiotic strains belonging to Lactobacillus casei, Lactobacillus delbrueckii ssp. bulgaricus, Lactobacillus paracasei, Lactobacillus plantarum, Lactobacillus rhamnosus, and Lactobacillus reuteri were screened. Resistance to heating (65 or 55°C for 10 min) varied markedly between strains. Adaptation at 42°C for 10 min increased the heat resistance at 55°C for 10 min of all probiotic lactobacilli. Heat-adapted L. delbrueckii ssp. bulgaricus SP5 (decimal reduction time at 55°C of 227.4 min) and L. paracasei BGP1 (decimal reduction time at 55°C of 40.8 min) showed the highest survival under heat conditions that mimicked the stretching of the curd and were used for the manufacture of Fior di Latte cheese. Two technology options were chosen: chemical (addition of lactic acid to milk) or biological (Streptococcus thermophilus as starter culture) acidification with or without addition of probiotics. As determined by random amplified polymorphic DNA-PCR and 16S rRNA gene analyses, the cell density of L. delbrueckii ssp. bulgaricus SP5 and L. paracasei BGP1 in chemically or biologically acidified Fior di Latte cheese was approximately 8.0 log(10)cfu/g. Microbiological, compositional, biochemical, and sensory analyses (panel test by 30 untrained judges) showed that the use of L. delbrueckii ssp. bulgaricus SP5 and L. paracasei BGP1 enhanced flavor formation and shelf-life of Fior di Latte cheeses.     

Viability of commercial probiotic cultures (L. acidophilus, Bifidobacterium sp., L. casei, L. paracasei and L. rhamnosus) in cheddar cheese

Six batches of cheddar cheese were manufactured containing different combinations of commercially available probiotic cultures from three suppliers. Duplicate cheeses contained the organisms of each supplier, a Bifidobacterium spp. (each supplier), a Lactobacillus acidophilus (2 suppliers), and either Lactobacillus casei, Lactobacillus paracasei, or Lactobacillus rhamnosus. Using selective media, the different strains were assessed for viability during cheddar cheese maturation over 32 weeks. The Bifidobacterium sp. remained at high numbers with the three strains being present in cheese at 4 x 10(7), 1.4 x 10(8), and 5 x 10(8) CFU/g after 32 weeks. Similarly the L. casei (2 x 10(7) CFU/g), L. paracasei (1.6 x 10(7) CFU/g), and L. rhamnosus (9 x 10(8) CFU/g) strains survived well; however, the L. acidophilus strains performed poorly with both decreasing in a similar manner to be present at 3.6 x 10(3) CFU/g and 4.9 x 10(3) CFU/g after 32 weeks. This study indicates that cheddar cheese is a good vehicle for a variety of commercial probiotics but survival of L. acidophilus strains will need to be improved.     

Lipolysis in probiotic and synbiotic cheese: The influence of probiotic bacteria, prebiotic compounds and ripening time on free fatty acid profiles

The influence of probiotic bacteria (Lactobacillus casei-01, Bifidobacterium lactis B94), prebiotic compounds (FOS and inulin) and ripening time (0-60 days) on the free fatty acid (FFA) profile of cheese, with special emphasis on the conjugated linoleic acid (CLA) content, was investigated. After 60 days of ripening, 10⁹-10¹⁰ cfu g⁻¹ cheese were recorded in both probiotic and synbiotic cheeses, despite harsh conditions of low pH values (4.1-5.1) and low moisture content (<30%, w/w). Increases in total FFA and CLA were observed throughout the ripening period, especially in synbiotic cheeses containing FOS and inulin (50:50) inoculated with B. lactis B94. The addition of FOS alone or combined with inulin did not significantly affect probiotic strain growth and viability during the ripening period; however, the advantage of the addition of prebiotic compounds in probiotic cheese manufacture is that it may allow the production of cheeses with improved performance as far as functional CLA compounds are concerned, as well as an improved nutritional quality reflected in a lower atherogenicity index.     

HYGIENIC PARAMETERS, TOXINS AND PATHOGEN OCCURRENCE IN RAW MILK CHEESES

In total, 71 samples of retail raw milk cheeses produced or imported in Belgium and samples of Belgian farmhouse cheeses were examined for cotiforms, β-glucuronidase positive Escherichia coli, Escherichia coli O157 , Staphylococcus aureus, Salmonella spp. , Listeria spp. and Listeria monocytogenes. The presence of staphylococcal enterotoxins was investigated on samples with S. aureus counts higher than 10³ cfu/g. The incidence of coliforms, β-glucuronidase positive E. coli and S. aureus was higher in soft than in blue veined, semi-hard, hard and fresh cheeses. Four mold-ripened soft cheeses were positive for E. coli O157. One of the 4 cheeses was positive for verotoxin VT2. Staphylococcal enterotoxins were detected in 1 soft redsmear cheese, which was positive for L. monocytogenes. L. monocytogenes was also detected in one fresh cheese . Salmonella was not detected in any of the 71 raw milk cheeses.     

Incorporation and Survival of Probiotic Bacteria in Whey Cheese Matrices

ABSTRACT: The viabilities of probiotic strains of Lactobacillus acidophilus, Lactobacillus paracasei, Bifidobacterium animalis , and Lactobacillus brevis were studied following incorporation in a whey cheese matrix. Experimental production of plain, as well as sugar-added or salt-added whey cheeses, was based on the traditional manufacture protocol of Requeijäo, a Portuguese whey cheese that essentially results from protein denaturation via heating of whey at about 85°C. After inoculation, the experimental whey cheeses were incubated at 7°C for 28 d. Our results have shown that all strains considered were able to maintain (or even increase) their initial viable numbers; L. paracasei ssp. paracasei strain LCS-1 and L. acidophilus strain Ki exhibited the highest cell viability in plain Requeijão by the end of the storage period—an increase of ca. 2 log cycles in their viable numbers was actually recorded. Among the parameters studied, bacterial species and matrix nature had the most important effect upon viable counts, whereas time of storage was the least important.     

Production of hard cheese from caprine milk by the use of two types of probiotic cultures as adjuncts

Hard cheeses (Kefalotyri-like) were manufactured from caprine milk with yoghurt as a starter (A), and with its partial replacement with the probiotic adjuncts Lactobacillus rhamnosus LC 705 (B) and/or Lactobacillus paracasei ssp. paracasei DC 412 (C). Both adjuncts retarded the growth of enterococci, and the environment in cheese B did not favour the recovery of lactic acid bacteria (LAB) on Rogosa agar. However, better recovery of the LAB population on M17 agar from cheeses B and C made with adjuncts was recorded early in ripening, and this was accompanied by a greater decrease in pH. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell protein demonstrated that cheese C, made with Lb. paracasei ssp. paracasei as adjunct, is a better vehicle for delivery of live probiotic cells (10 ⁷   cfu/g) to the gastrointestinal tract than cheese B, made with Lb. rhamnosus ; the latter did not belong to the predominant microflora of one out of the two B cheeses. Urea-PAGE electrophoresis results indicated that adjunct lactobacilli enhanced the degradation of both α _S -casein (α _S -CN) and β-casein (β-CN). In the fresh cheese, hydrolysis of α _S -CN was more rapid than β-CN, and the free amino acid content of B and C was higher than in A. Lipolysis products were also higher in B and C than in A as ripening progressed, and the organoleptic characteristics of these cheeses resulted in higher scores, in the order C > B > A. Thus, making Kefalotyri-like cheese from caprine milk with probiotic lactobacilli, particularly Lb. paracasei ssp. paracasei, as adjunct can be considered an effective way of producing a cheese with a large number of probiotic cells.     

Indigenous raw milk microbiota influences the bacterial development in traditional cheese from an alpine natural park

Nostrano di Primiero is a 6-month ripened cheese produced from raw milk collected in the Paneveggio-Pale di San Martino Natural Park area in the Italian Dolomites. In summer, this cheese is made using milk collected from two different areas, Passo Rolle and Vanoi, in the Paneveggio Natural Park. During the experiment, the milk from the two areas was separately processed, and cheeses were made in the same cheese factory using the same technological process. The microbiota of raw milk and cheeses of the two areas was isolated and the dominant population was monitored by RAPD analysis and identified by 16S rRNA sequence. The milk of the Passo Rolle area was mainly composed of mesophilic strains, thermophilic Streptococcus thermophilus, and low amounts of enterococci were also found; the milk of the Vanoi area was dominated by mesophilic microbiota mostly Lactococcus lactis ssp. cremoris and ssp. lactis and Lactobacillus paracasei ssp. paracasei. The plating of the natural starter culture revealed the presence of a relevant community of thermophilic cocci and lower amounts of enterococci. The dynamic population analysis showed the importance of the natural starter culture in the first 2 days of cheese ripening in both cheeses. Moreover, the large biodiversity observed in the raw milks was also detected in the cheeses during ripening. The Vanoi cheese was dominated by Enterococcus faecium and Streptococcus macedonicus in the first two days and mesophilic 21 Lb. paracasei ssp. paracasei became the most represented population after 15 days of ripening. In the first few days, the Rolle cheese was characterized by being mainly composed of thermophilic S. macedonicus and S. thermophilus and secondarily by mesophilic cocci. During ripening, the microbiota composition changed, and at 15 days, mesophilic lactobacilli were the dominant population, but later, this was mainly composed of mesophilic cocci and lactobacilli. The taxonomical identification by 16S rRNA sequence confirmed a large biodiversity related to raw milk microbiota and only five strains of S. macedonicus, Lactobacillus plantarum, 21 Lb. paracasei ssp. paracasei, Lactobacillus fermentum and E. faecium were detected in both cheeses.     

凝固型绵羊奶酸奶的发酵特性及活菌数变化

研究凝固型的绵羊奶与牛奶酸奶发酵特性和贮存期特性,利用pH计、酸度滴定、质构仪、电子舌、活菌计数及感官评价对其pH值、滴定酸度、质构特性、味觉特点、活菌数和感官评分进行分析。结果表明：在发酵过程中绵羊奶与牛奶有相同的pH值变化规律,即前2.5 h下降非常缓慢,之后迅速下降,在凝乳前0.5 h下降变缓直到凝乳结束,达到发酵终点的时间分别为5 h和4.5 h;在4 ℃贮存0～24 d期间,酸奶的pH值都在逐渐下降,牛奶酸奶比绵羊奶酸奶下降更大;滴定酸度方面起始时绵羊奶比牛奶高,达到发酵终点时也明显高于牛奶;质构测定结果为YSM（添加益生菌干酪-张发酵的凝固型绵羊奶酸奶）、JDM（嗜热链球菌与保加利亚乳杆菌共同发酵的经典凝固型绵羊奶酸奶）具有更高的硬度和稠度,黏聚性和黏性指数也显著高于JDN（嗜热链球菌与保加利亚乳杆菌共同发酵的经典凝固型牛奶酸奶）,奶的种类为影响酸奶硬度、稠度、黏聚性和黏性指数的主要因素,益生菌干酪-张的添加对这些指标的影响很小;电子舌测定结果为丰富性味感值绵羊奶酸奶明显高于牛奶酸奶,酸感值则低于牛奶酸奶,甜、苦、咸、涩、鲜感值差异不明显;感官评价方面绵羊奶酸奶综合评分高于牛奶酸奶,差异性主要体现在滋味、组织状态和喜爱程度上,在色泽和气味方差异不明显;在4 ℃、21 d贮存期间酸奶的活菌数都在逐渐降低,添加益生菌干酪-张的绵羊奶酸奶活菌数最多,第21天时活菌数分别是普通绵羊奶酸奶和牛奶酸奶的10 倍和100 倍以上,干酪-张对绵羊奶酸奶4 ℃贮存期间活菌数的维持有较好作用。同时,实验结果表明：益生菌干酪-张可以作为发酵剂之一与经典的酸奶发酵剂嗜热链球菌和保加利亚乳杆菌搭配用于凝固型绵羊奶酸奶的制作,以增加其功能价值。     

Effect of inulin and Lactobacillus paracasei on sensory and instrumental texture properties of functional chocolate mousse

BACKGROUND: This study evaluated the effect of a potentially probiotic bacteria (Lactobacillus paracasei subsp. paracasei LBC 82), added solely or together with the prebiotic ingredient inulin on instrumental texture attributes and sensory properties of a functional chocolate mousse during storage at 4 ± 1 °C for up to 28 days. RESULTS: The addition of Lactobacillus paracasei resulted in a firmer and more adhesive chocolate mousse. This effect was intensified with the presence of inulin in the synbiotic formulation (5.24 N and ? 0.956 N, respectively, for firmness and adhesiveness after 28 days of storage) (P < 0.05). L. paracasei population did not vary (P > 0.05) during storage (always between 7.27 and 7.35 log cfu g^?1), both for the probiotic and the synbiotic mousses. Synbiotic mousse differed from control and probiotic mousses during storage with respect to the color attribute. Moreover, both probiotic and synbiotic mousses presented taste, aroma and texture perceptions which were different from one another and from the control mousse after 14 and 21 days of storage. CONCLUSION: The use of inulin, together with the potentially probiotic strain of Lactobacillus paracasei subsp. paracasei, is advantageous, conferring potentially symbiotic potential to the chocolate mousse, as well as favorable texture and sensory properties. Copyright © 2008 Society of Chemical Industry     

Production of functional probiotic, prebiotic, and synbiotic ice creams

In this work, 3 types of ice cream were produced: a probiotic ice cream produced by adding potentially probiotic microorganisms such as Lactobacillus casei and Lactobacillus rhamnosus; a prebiotic ice cream produced by adding inulin, a prebiotic substrate; and a synbiotic ice cream produced by adding probiotic microorganisms and inulin in combination. In addition to microbial counts, pH, acidity, and physical and functional properties of the ice creams were evaluated. The experimental ice creams preserved the probiotic bacteria and had counts of viable lactic acid bacteria after frozen storage that met the minimum required to achieve probiotic effects. Moreover, most of the ice creams showed good nutritional and sensory properties, with the best results obtained with Lb. casei and 2.5% inulin.     

Phage inactivation of Staphylococcus aureus in fresh and hard-type cheeses

Bacteriophages are regarded as natural antibacterial agents in food since they are able to specifically infect and lyse food-borne pathogenic bacteria without disturbing the indigenous microbiota. Two Staphylococcus aureus obligately lytic bacteriophages (vB_SauS-phi-IPLA35 and vB_SauS-phi-SauS-IPLA88), previously isolated from the dairy environment, were evaluated for their potential as biocontrol agents against this pathogenic microorganism in both fresh and hard-type cheeses. Pasteurized milk was contaminated with S. aureus Sa9 (about 10(6)CFU/mL) and a cocktail of the two lytic phages (about 10(6)PFU/mL) was also added. For control purposes, cheeses were manufactured without addition of phages. In both types of cheeses, the presence of phages resulted in a notorious decrease of S. aureus viable counts during curdling. In test fresh cheeses, a reduction of 3.83log CFU/g of S. aureus occurred in 3h compared with control cheese, and viable counts were under the detection limits after 6h. The staphylococcal strain was undetected in both test and control cheeses at the end of the curdling process (24h) and, of note, no re-growth occurred during cold storage. In hard cheeses, the presence of phages resulted in a continuous reduction of staphylococcal counts. In curd, viable counts of S. aureus were reduced by 4.64log CFU/g compared with the control cheeses. At the end of ripening, 1.24log CFU/g of the staphylococcal strain was still detected in test cheeses whereas 6.73log CFU/g was present in control cheeses. Starter strains were not affected by the presence of phages in the cheese making processes and cheeses maintained their expected physico-chemical properties.     

Incorporation of probiotic bacteria in whey cheese: decreasing the risk of microbial contamination

For dairy products that are consumed fresh, contamination by spoilage microorganisms and pathogens from the environment is a major concern. Contamination has been associated with a number of outbreaks of foodborne illnesses; however, consistent data pertaining to the microbial safety of whey cheeses specifically have not been reported. Hence, the goals of this research effort were (i) to manufacture a probiotic whey cheese with Bifidobacterium animalis and Lactobacillus casei and (ii) to assess the antimicrobial activity of these probiotics against a set of foodborne pathogens (Listeria innocua, Salmonella Enteritidis, and Staphylococcus aureus) and food spoilage microorganisms (Pseudomonas aeruginosa and Escherichia coli). Three ranges of these microbial contaminants were used for inoculation of cheeses: 10(3) to 10(4), 10(4) to 10(6), and 10(6) to 10(8) CFU/g. Inoculation in plain culture medium served as a control. The inhibition produced by the probiotics was calculated, and the major effect was found to be bacteriostatic. In specific cases, full inhibition was observed, i.e., by B. animalis against P. aeruginosa and by L. casei against Salmonella Enteritidis and L. innocua. Conversely, the least inhibition was detected for L. casei against P. aeruginosa. Our results suggest that use of these probiotic strains can extend the shelf life of whey cheeses and make them safer by delaying or preventing growth of common contaminant bacteria.     

Potentially probiotic and synbiotic chocolate mousse

Several studies in recent years have shown the benefits deriving from the ingestion of probiotics, and a large number of products containing lactobacilli and bifidobacteria have been formulated. The purpose of this study was to develop a chocolate mousse to which probiotic and prebiotic ingredients were added, and verify the perspectives of the product with regard to potential for consumer health benefits and sensorial acceptance. Probiotic and synbiotic chocolate mousse supplemented with Lactobacillus paracasei subsp. paracasei LBC 82, solely (P) or together with the prebiotic ingredient inulin (S), were prepared, as well as a control mousse (C). The products were monitored for the population of L. paracasei and contaminants, during storage at 5 °C for up to 28 days, and sensory preference was also tested. Storage trials showed that the viability of the probiotic was retained over 28 days, but the growth of yeasts and moulds might limit the shelf-life of the product. Chocolate mousse was shown to be an excellent vehicle for the delivery of L. paracasei, and the prebiotic ingredient inulin did not interfere in its viability. Moreover, the addition of the probiotic microorganism and of the prebiotic ingredient did not interfere in the sensorial preference of the product.     

A review of the microbiological hazards of dairy products made from raw milk

This review concentrates on information concerning microbiological hazards possibly present in raw milk dairy products, in particular cheese, butter, cream and buttermilk. The main microbiological hazards of raw milk cheeses (especially soft and fresh cheeses) are linked to Listeria monocytogenes, verocytotoxin-producing Escherichia coli (VTEC), Staphylococcus aureus, Salmonella and Campylobacter. L. monocytogenes, VTEC and S. aureus have been identified as microbiological hazards in raw milk butter and cream albeit to a lesser extent because of a reduced growth potential compared with cheese. In endemic areas, raw milk dairy products may also be contaminated with Brucella spp., Mycobacterium bovis and the tick-borne encephalitis virus (TBEV). Potential risks due to Coxiella burnetii and Mycobacterium avium subsp. paratuberculosis (MAP) are discussed. Pasteurisation ensures inactivation of vegetative pathogenic microorganisms, which increases the safety of products made thereof compared with dairy products made from raw milk. Several control measures from farm to fork are discussed.     

Starter culture activity in refrigerated fermented soymilk.

The refrigerated shelf life of soymilk fermented with single cultures of Lactobacillus fermentum, L. casei, Streptococcus salivarius subsp. thermophilus, and Bifidobacterium longum was evaluated. During storage at 4 degrees C for 28 days, the stability of the microflora differed markedly among the starter cultures. After 28 days, the average numbers of S. salivarius subsp. thermophilus decreased by two log cycles to 6.0 x 10(7) CFU/ml, whereas those of L. casei increased gradually by more than two log cycles to 4.6 x 10(9) CFU/ml. Numbers of B. longum and L. fermentum remained moderately high (8.7 x 10(8) CFU/ml and 3.7 x 10(8) CFU/ml, respectively) even after 28 days of storage. S. salivarius subsp. thermophilus and L. casei continued to metabolize sucrose during the storage period, but the pattern of consumption was different among the strains. The other starter cultures did not seem to have significant activity (P > 0.05) on the residual sugars. In most cases, L(+)-lactate predominated.     

Modelling the survival of starter lactic acid bacteria and Bifidobacterium bifidum in single and simultaneous cultures

The inactivation kinetics at 4 degrees C of Bifidobacterium bifidum, Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus, cultured alone or consociated in a laboratory medium (modified MRS broth), were modelled through the Weibull model and a second-order polynomial equation. The initial cell number of S. thermophilus and L. delbrueckii subsp. bulgaricus was approximately 6-7log (CFU/ml); the viability loss after 30 days of storage was 2.87 and 1.99log (CFU/l) for L. delbruckii subsp. bulgaricus and S. thermophilus, cultured alone, respectively; whereas the consociation of lactobacilli and streptococci with bifidobacteria reduced viability loss during storage (0.28 and 0.54log CFU/l for lactobacilli and streptococci, respectively). Finally, the consociation of lactobacilli and streptococci with B. bifidum improved their oxygen uptake.