Viability of probiotic micro-organisms (Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp. lactis Bb-12) in ice cream

The purpose of this research was to determine the survival of two probiotic micro-organisms in ice creams (4% fat). The micro-organisms were Lactobacillus acidophilus La-5 and Bifidobacterium animalis subsp . lactis Bb-12 . To meet this objective, an ice cream mixture was formulated and subjected to three treatments. Treatment 1 was inoculated with L. acidophilus , treatment 2 with B. lactis and the third treatment was inoculated with a mixture of both bacteria inoculated in 1 : 1 proportions. The inoculation was with 4% culture for each treatment. The final products were stored at −25°C for 60 days. The ice cream inoculated with L. acidophilus had a final concentration of 2 × 10 ⁶ cfu/g and the survival rate was 87%. The treatment inoculated with B. lactis had a final concentration of 9 × 10 ⁶ cfu/g, with a logarithmic decrease of 10%. When both micro-organisms were inoculated together, the survival rate was 86%.     

荧光定量PCR法检测益生菌饮料中Lactobacillus casei Zhang和Bifidobacterium lactis V9

益生菌活菌数是益生菌产品最重要的指标,而检测益生菌方法的准确性和科学性则至关重要.本文采用荧光定量PCR法同时定量检测益生菌饮料中Lactobacillus casei Zhang(L.casei Zhang)和Bifidobacterium lactis V9(B.lactis V9)的活菌数,并与平板菌落计数法进行比较.结果表明,荧光定量PCR法测得L.casei Zhang活菌数与平板菌落计数法测得活菌数差异不显著;而采用荧光定量PCR法测得B.lactis V9活菌数显著高于平板菌落计数法.荧光定量PCR法灵敏、特异、简便快速,可定量检测并真实反应L.casei Zhang和B.lactis V9的活菌数.     

益生菌Lactobacillus casei Zhang和Bifidobacterium lactis V9接种比例及乳固形物含量对其活菌数的影响

将益生菌Lactobacillus casei Zhang和Bifidobacterium lactis V9按1∶3、1∶1、3∶1(总接种量为2×106cfu/g)接种于总固形物含量为10%、12%、14%、16%的脱脂牛乳中,37℃恒温发酵至pH 4.5,于4℃贮藏28 d。测定发酵及贮藏结束2株益生菌活菌数。试验结果表明,发酵结束,当研究固形物质量分数相同,接种比例为3∶1时,L.casei Zhang和B.lactis V9的活菌数最高。贮藏结束,当接种比例相同,所含乳固形物质量分数为14%时,两株益生菌存活率显著高于其他固形物含量组(P<0.05)。本研究显示,L.casei Zhang和B.lactis接种比例为3∶1,乳固形物质量分数为14%时,两株益生菌生长良好且存活率高,适宜生产应用。     

Edible table (bio)spread containing potentially probiotic Lactobacillus and Bifidobacterium species

A prototype of a reduced fat (60% w/w) edible table biospread, with an added viable, nongrowing, mixed-strain and potentially probiotic culture was developed. Conventional commercial aqueous-phase ingredient and reduced fat spread processing technologies were modified to achieve acceptable strain viability ( ≥   10⁵ cfu/mL) during scraped-surface heat exchange emulsion processing and biospread shelf life. The modifications consisted of:

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   spilt-stream pasteurization of the aqueous and lipid phases (thereby obviating the need for in-line pasteurization of the water-in-oil emulsion during processing);

       
  
  

动物双歧杆菌乳亚种HCS04-002发酵条件优化

为实现动物双歧杆菌乳亚种（Bifidobacterium animalis subsp. lactis）HCS04-002的高活菌数培养,获得其生长的最适发酵条件,对发酵工艺和发酵培养基分别进行优化。以菌泥收率为考察指标,通过单因素及正交试验对培养温度、接种量和初始pH值等发酵工艺参数进行了优化;以发酵液活菌数为响应值,通过单因素试验和Box-Behnken试验优化发酵培养基。结果表明,动物双歧杆菌乳亚种HCS04-002最佳发酵条件为：培养温度39 ℃、接种量3%、初始pH值为7.2;最佳发酵培养基组分为：酵母蛋白胨24 g/L、酵母浸出物30 g/L、葡萄糖19 g/L、乳糖11 g/L。在此优化条件下,菌株HCS04-002菌悬液活菌数达2.73×109 CFU/mL。     

Production and evaluation of a probiotic yogurt using Lactobacillus casei ssp. casei

Skimmed milk was inoculated with the commercial starter and Lactobacillus casei ssp. casei. pH changes, viable counts, and organoleptic properties of the produced control and probiotic yogurts were analysed. The pH decrease during the fermentation period was faster in the milk inoculated with L. casei plus starter. The growth of both starters in probiotic yogurt was significantly lower than their growth in control yogurt during the fermentation period. The viable count of the probiotic bacterium remained higher than the standard limit for probiotic products. There was no significant difference between the organoleptic properties of the control and the probiotic yogurts.     

Microbiological and physicochemical properties of dry‐cured neck inoculated with probiotic of Bifidobacterium animalis ssp. lactis BB‐12

The effect of inoculum level of Bifidobacterium animalis ssp. lactis BB‐12 probiotic strain and ripening period on the quality of dry‐cured neck was studied. The microbiological parameters (Enterobacteriaceae, LAB and TVC) and physicochemical attributes (pH value, a_w, TBARS index, colour) were determined directly after fermentation at 15 °C for 3 weeks, after 6 and 12 months of ripening at 4 °C. The highest LAB count and a lower pH value were found in the meat inoculated with probiotic strain at 6.6 log cfu g^?1 (B2) followed by inoculation with probiotic strain at 6.3 log cfu g^?1 (B1). Level of inoculation had not had an influence on water activity, TBARS index and total colour parameters. Changes of fat oxidation during half‐year of ripening were limited in probiotic meat samples compared to naturally fermented control meat (C). Based on the results, it can be concluded that the most favourable physicochemical and microbiological parameters of the dry‐cured neck were obtained after 6 months of ripening. At that time, the Bifidobacterium BB‐12 at both levels is a good potential starter for meat fermentation.     

Antihypertensive and antithrombotic activities of a commercial fermented milk product made with Lactobacillus casei Shirota and Streptococcus thermophilus

Peptides which inhibit the human angiotensin‐converting enzyme (ACE) may be released during milk fermentation, and the micro‐organisms or fermentation conditions influence the specific peptides produced. The aim of this study was to evaluate the ACE inhibitory and antithrombotic activities of a fermented milk product commercially available in Mexico. Viable cell numbers, protein hydrolysis and the pH remained constant during refrigerated storage. The IC₅₀ of ACE inhibitory activity was 31.38 mg/mL. Eight peptide fractions exhibited ACE inhibitory activity and six showed antithrombotic activity. Two fractions showed both. This is the first time that both activities have been reported in a commercial probiotic product.     

Calcium alginate‐resistant starch mixed gel improved the survival of Bifidobacterium animalis subsp. lactis Bb12 and Lactobacillus rhamnosus LBRE‐LSAS in yogurt and simulated gastrointestinal conditions

The aim of this study was to investigate the protective effect of microencapsulation in calcium alginate‐resistant starch mixed gel of a new human isolated strain of Lactobacillus rhamnosus LBRE‐LSAS compared with the probiotic strain of Bifidobacterium animalis subsp. lactis Bb12. Influence of microencapsulation was tested under deleterious digestive environment, when challenged to salivary α‐amylase, to simulated gastric fluid and to simulated intestinal fluid. Bacterial survival, post‐acidifying activity and exopolysaccharides (EPS) content in stored mix yogurt were assessed. Integrity of the beads was acceptable under α‐amylase levels largely higher than those found in human saliva. Under simulated gastrointestinal model, viable cell counts of encapsulated cells were significantly higher than those observed with free cells and remained at the recommended levels. Additionally, microencapsulation allowed an improved viability of bacteria and generated higher EPS amounts in mix yogurt stored at 4 °C. Our results indicate that calcium alginate‐resistant starch beads extend survival under digestive conditions and in yogurt and could be used as an efficient delivery system for probiotics.     

Microencapsulation of Bifidobacterium animalis subsp. lactis in Modified Alginate-chitosan Beads and Evaluation of Survival in Simulated Gastrointestinal Conditions

Bifidobacterium animalis subsp. lactis was entrapped in alginate, alginate-chitosan, alginate-chitosan-Sureteric and alginate-chitosan-Acryl-Eze. Survival and in vitro release of bifidobacteria from the microparticles were investigated under conditions simulating gastrointestinal fluids covering the pH range from 1.5 to 7.5, with and without pepsin (3gL^-1), pancreatin (1gL^-1), and bile (10gL^-1). All types of microcapsules protected B. animalis, but the use of chitosan and enteric polymers in the formulation of the beads, especially Acryl-Eze, enhanced the beneficial effects of the microencapsulation technique. Besides promoting the controlled release of bifidobacteria in simulated gastrointestinal juices, the microencapsulation with enteric polymers improved the survival rate of these microorganisms.     

Volatile Profile of Non-Fermented Milk and Milk Fermented by BifidoBacterium animalis subsp. lactis

The aim of this work was to determine low-molecular volatile compounds in milk supplemented with the strain Bifidobacterium animalis subsp. lactis Bb-12 with or without fermentation process, stored at 6°C for 4 weeks. The chromatographic analysis of probiotic-supplemented non-fermented milk and milk fermented by strain Bb-12 revealed the presence of volatile compounds, such as ketones, organic acid, and alcohols. The changes in the volatile profile were influenced by fermentation process and/or prolonged cold storage. The fermentative activity of strain Bb-12 and its intensification between the 2nd and 4th weeks were observed in the cold storage condition of milk.     

实时荧光定量PCR法鉴定婴幼儿配方乳粉中动物双歧杆菌乳亚种

该研究通过系统发育树分析确定目标基因,并设计引物和探针,建立一种婴幼儿配方乳粉中动物双歧杆菌乳亚种（Bifidobacterium animalis subsp. lactis）的实时荧光定量聚合酶链式反应（RT-fqPCR）鉴定方法。通过特异性、灵敏性和抗干扰实验对该方法进行验证,并对市售的64份标识含有动物双歧杆菌乳亚种的婴幼儿配方乳粉样品进行检测。结果表明,atpD基因在动物双歧杆菌乳亚种间具有较高的种间特异性,种间差异率＞10%,确定其为目标基因。基于该基因建立的RT-fqPCR方法能够特异性的检测动物双歧杆菌乳亚种,检测绝对灵敏度可以达到1 pg/μL,相对灵敏度可以达到103 CFU/mL;基因水平和培养物水平抗干扰能力良好。采用该方法从64份标识含有动物双歧杆菌乳亚种的乳粉样品中均能检测出动物双歧杆菌乳亚种,表明基于atpD基因建立的RT-fqPCR方法能够快速准确的对动物双歧杆菌乳亚种进行检测。     

动物双歧杆菌乳亚种XLTG11对克林霉素诱导的抗生素相关性腹泻的改善作用

目的：通过克林霉素诱导抗生素相关性腹泻(antibiotic-associated diarrhea,AAD)模型,探究动物双歧杆菌乳亚种XLTG11缓解小鼠AAD的作用。方法：将48只6周龄C57BL/6N雄鼠随机分为4组：对照组、模型组、低剂量组和高剂量组,除对照组外,各组小鼠连续14 d灌胃克林霉素(250 mg/(kg m_b·d))诱导AAD模型,然后低剂量组和高剂量组灌胃不同剂量(0.2 mL,5×10⁶、1×10⁷ CFU)动物双歧杆菌乳亚种XLTG11,测定小鼠体质量增长量、盲肠质量、粪便含水量和粪便稠度,测定结肠肿瘤坏死因子α、白细胞介素6(interleukin 6,IL-6)、IL-1β、IL-10水平,血清脂多糖(lipopolysaccharide,LPS)和D-乳酸质量浓度,测定肠道菌群组成及短链脂肪酸含量,以及肠道屏障和核因子κB(nuclear factor kappa-B,NF-κB)信号通路相关基因表达水平。结果：高剂量动物双歧杆菌乳亚种XLTG11显著提高AAD模型小鼠的体质量增长量和...     

Lactobacillus delbrueckii subsp. bulgaricus和Streptococcus thermophilus接种比例对Bifidobacterium lactis益生菌发酵乳品质的影响

将Lactobacillus delbrueckii subsp.bulgaricus ND02(LB-ND02)和Streptococcus thermophilus ND03(ST-ND03)按1∶1、1∶10、1∶100、1∶1000接种于脱脂乳中,同时接入益生菌Bifidobacterium lactis V9(B.lactis V9,接种量为2.0×107g-1),于42℃进行发酵。通过对发酵及贮藏过程中发酵乳指标的测定,评价LB-ND02和ST-ND03的接种比例对发酵乳品质的影响。结果表明,随着LB-ND02接种比例减小,凝乳时间显著延长,B.lactis V9活菌数显著提高。4℃贮藏28 d后,随LB-ND02接种比例减小,B.lactis V9存活率差异显著,后酸化也显著减弱。研究发现,LB-ND02和ST-ND03的接种比例,显著影响发酵乳的发酵时间、B.lactis V9活菌数、后酸化及黏度。     

Viability of probiotic micro-organisms during storage, postacidification and sensory analysis of fat-free yogurts with added whey protein concentrate

The aim of this research was to evaluate the effect of the addition of whey protein concentrate (WPC) on the viability of Lactobacillus acidophilus and Bifidobacterium longum and on postacidification throughout the shelf life of fat-free yogurts, and also to analyse the sensory characteristics of the products. Postacidification was not significantly changed by the addition of WPC, but was decreased by Lactobacillus bulgaricus inoculation. WPC did not influence the viability of the lactic acid bacteria ( L. bulgaricus and Streptococcus thermophilus ), but it improved the growth and survival of the micro-organisms L. acidophilus and B. longum , especially the former. The panellists did not identify significant differences ( P <  0.05) of the yogurts due to the addition of WPC.     

Probiotic potential and sensory properties of coconut flan supplemented with Lactobacillus paracasei and Bifidobacterium lactis

The effect of probiotic cultures on sensory performance of coconut flan during storage at 5 °C and the viability of these micro organisms for up to 28 days were investigated. Sensory analyses of the product were performed after 7, 14 and 21 days of storage. Coconut flans were produced with no addition of cultures (T1, control), or supplemented with Bifidobacterium lactis (T2), Lactobacillus paracasei (T3) and B. lactis  +  L. paracasei (T4). Populations of L. paracasei and B. lactis as single or in co-culture remained above 7 log CFU g⁻¹ during the entire storage period. Viability of L. paracasei was higher for T3. All products were well accepted and no significant differences ( P  > 0.05) were detected between the coconut flans studied. The addition of L. paracasei and B. lactis to coconut flan resulted in its having great potential as a functional food, which has high sensory acceptability.     

Hydrolysis of β-casein (193-209) Fragment by Whole Cells and Fractions of Lactobacillus casei and Lactococcus lactis

Whole cells and fractions of Lactococcus lactis subsp. lactis IFPL 359 and Lactobacillus casei subsp. casei IFPL731 were studied. Hydrolysis products were separated by reversed-phase, high-performance liquid chromatography (RPHPLC). Under conditions, pH 5.2 and 3% NaCl, L. casei IFPL 731 was more active in hydrolysis of the b-casein (f193-209) peptide than was L. lactis IFPL 359. This hydrolyzing activity was attributed for L. casei IFPL 731 by the cell-wall proteinase. Hydrolysis of the peptide by the intracellular extract of L. casei IFPL731 was mainly located in the fraction that contained endopeptidase and Pep N aminopeptidase activities. Results may help provide approaches and treatments to control bitterness in cheese products.