Spray drying conditions for orange juice incorporated with lactic acid bacteria

This work aimed to develop an orange juice powder by spray drying with lactic acid bacteria (Lactobacillus plantarum 299v and Pediococcus acidilactici HA‐6111‐2), testing their survival both during drying and storage (room temperature and 4 °C). Initially, the best conditions for spray drying were chosen to allow the best survival of each LAB: (i) inlet air temperature of 120 °C and (ii) 0.5:2 ratio of the orange juice soluble solids and drying agent added (prebiotics: 10 DE maltodextrin or gum Arabic). Survival of LAB was not affected by drying process, and it was higher when cultures were stored at 4 °C. A slightly higher protection was conferred by 10 DE maltodextrin, in the case of L. plantarum and at 4 °C. Pediococcus acidilactici was more resistant during storage at 4 °C, with logarithmic reductions lower than 1 log‐unit. It was demonstrated that it is possible to produce a functional nondairy product, orange juice powder supplemented with prebiotic compounds, containing viable LAB for at least 7 months, when stored at 4 °C.     

Enhancement of survival of probiotic and non-probiotic lactic acid bacteria by yeasts in fermented milk under non-refrigerated conditions

The effects of yeasts on the survival of probiotic and non-probiotic lactic acid bacteria (LAB) were studied in fermented milk under non-refrigerated conditions (30 °C) with a view to develop ambient-stable fermented milk with live LAB. Five yeasts tested (Saccharomyces bayanus, Williopsis saturnus var. saturnus, Yarrowia lipolytica, Candida kefyr and Kluyveromyces marxianus) enhanced the survival of Lactobacillus bulgaricus (but not Streptococcus thermophilus) in a mixed yoghurt culture in yoghurt by ~ 10² to 10⁵-fold. Seven yeasts examined (Candida krusei, Geotrichum candidum, Pichia subpelliculosa, Kloeckera apiculata, Pichia membranifaciens, Schizosaccharomyces pombe and Y. lipolytica) improved the survival of Lactobacillus rhamnosus in fermented milk by ~ 10³ to 10⁶-fold. W. saturnus var. saturnus enhanced the survival of Lactobacillus acidophilus, L. rhamnosus (probiotic) and Lactobacillus reuteri by up to 10⁶-fold, but the same yeast failed to improve the survival of Lactobacillus johnsonii (probiotic), S. thermophilus and L. bulgaricus in fermented milk. These results provide definitive evidence that yeasts possess stability-enhancing effects on LAB and that the specific effects of yeasts on LAB stability vary with yeasts as well as with LAB. However, the molecular mechanism of such interaction of yeasts with LAB remains to be found.     

Manufacture and characterization of functional emmer beverages fermented by selected lactic acid bacteria

Autochthonous lactic acid bacteria from emmer flour were screened based on the kinetic of acidification and used to ferment beverages containing emmer flour, emmer gelatinized flour, and emmer malt at percentages ranging 5-30% (wt/wt). Preliminarily, the concentration of raw flour and malt was selected based on sensory analysis. Different protocols were set up for the manufacture of four different beverages which used Lactobacillus plantarum 6E as the starter. Emmer beverages were mainly differentiated based on the concentration of organic acids, carbohydrates, amino acids, dietary fibers, vitamins, antioxidant and phytase activities, and volatiles and sensory profiles. Wheat flour bread was used as the control to determine the hydrolysis index (HI = 100), as an indirect estimation of the glycemic index. The beverage made with 30% (wt/wt) of gelatinized flour showed an HI of 56%, its viscosity was improved by using an EPS-producing strain and it allowed the survival of the potential probiotic Lactobacillus rhamnosus SP1 at cell density of ca. 5 × 10⁸ cfu/ml throughout storage at 4 °C. Among the exploited biotechnological options, this latter beverage could be considered as a promising novel functional food.     

Screening of some potentially probiotic lactic acid bacteria for their ability to synthesis conjugated linoleic acid

Strains of potentially probiotic lactobacilli, propionibacteria, leuconostoc, lactococcus, enterococcus, and pediococcus, were tested for their ability to convert linoleic acid to conjugated linoleic acid (CLA). Growth and CLA production were followed during incubation for 48 h in reconstituted skim milk containing 0.2% lipolysed sesame oil. Lactococcus lactis subsp. lactis biovar diacetylactis and Leuconostoc mesenteroides subsp. mesenteroides gave the highest CLA production. Also, the effect of lipolysed oil concentration on the growth and CLA production of six strains were studied in medium containing 0.0–1% lipolysed oil. Leuconostoc mesenteroides subsp. mesenteroides and Lac. lactis subsp. lactis biovar diacetylactis gave maximum dienes in medium containing 0.6% and 0.8% lipolysed oil respectively.     

乳酸菌冷冻干燥保护剂的筛选

通过单因素比较和正交试验设计,确定适合保加利亚乳杆菌和嗜热链球菌的最佳冻干保护剂配方。通过对15种冻干保护剂单因素保护效果的比较,以及对选定的4种保护剂的正交试验结果,可以确定嗜热链球菌最佳冻干保护剂配方为脱脂乳粉12%、海藻糖1%、甘油3%、谷氨酸钠1%,保加利亚乳杆菌最佳冻干保护剂配方为脱脂乳粉8%、海藻糖1%、甘油2%、谷氨酸钠1.5%。     

Folate‐producing lactic acid bacteria from cow’s milk with probiotic characteristics

The probiotic potential of newly isolated lactic acid bacteria from cow’s milk was analysed and the efficacy of the selected isolates to produce folic acid was determined by microbiological assay. Two isolates, CM 22 and CM 28 were selected for folate production in skim milk medium and the net folate yield was 12.5 ng and 14.2 ng/mL respectively. The two isolates (CM 22 and CM 28) showed more than 98% similarity to Lactococcus subsp. cremoris and Lactococcus lactis subsp. lactis respectively by 16S rRNA sequencing.     

高效同化胆固醇乳酸菌菌株的筛选及在食品中的应用

从发酵食品中分离筛选能高效同化胆固醇的乳酸菌,以开发低胆固醇系列产品。从25个来源不同的样品中,分离筛选出8株乳酸菌,与活化出的8株已知乳酸菌共同在特殊培养基中培养,最后筛选出2株具有较高同化胆固醇能力的菌株。结果表明,嗜酸乳杆菌和植物乳杆菌应用于食品中,对食品风味影响较小,可大量应用。     

Assessment of the probiotic potential of lactic acid bacteria isolated from Minas artisanal cheese produced in the Campo das Vertentes region,Brazil

The microbiota of the Brazilian Minas artisanal cheese, made from raw milk, is not well known and may include probiotic bacteria. This study aimed to assess the in vitro and in vivo probiotic properties of the lactic acid bacteria isolated from these cheeses. Thirty‐six samples of the Lactobacillus/Pediococcus group were selected for in vitro investigation. Pediococcus acidilactici (PA2) and Lactobacillus plantarum (LP4) showed the best results and were tested for their ability to protect Salmonella Typhimurium orally infected mice. LP4 showed better probiotic potential than PA2 and allowed higher values of weight gain (P < 0.05). Thus, Lb. plantarumLP4 may have potential use as a probiotic in foods after future technological screening.     

Observations on the succession dynamics of lactic acid bacteria populations in chill-stored vacuum-packaged beef

Drip samples were collected at 4-week intervals from 10 vacuum-packaged beef striploins stored for 16 weeks at −1.5 °C and assayed for populations of lactic-acid bacteria (LAB), pH and spoilage-causing fermentation products. A total of 15 LAB species were identified using pulsed-field gel electrophoresis and biochemical analysis. A pattern of succession was observed during storage between strains of Carnobacterium, Lactobacillus, Leuconostoc and Pediococcus. Acetic acid production was associated with increasing LAB populations generally and butyric acid production was associated with the development of a particular strain of Leuconostoc. Changes in pH is postulated as a driver of succession.     

Lactic acid starter and probiotic bacteria: a comparative “in vitro” study of probiotic characteristics and biological barrier resistance

Probiotic characteristics (deconjugation of bile salts, hydrophobicity and β-galactosidase activity) and the resistance to biological barriers (gastric juice and bile salts) of 24 strains of lactic acid starter bacteria (Streptococcus thermophilus, Lactobacillus delbrueckii subsp. bulgaricus and Lactococcus lactis) and 24 strains of probiotic bacteria (Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus rhamnosus and bifidobacteria) were compared. Among the probiotic bacteria tested, Lactobacillus acidophilus was the most interesting species since it showed high values of resistance to gastric juice and bile, hydrophobicity and β-galactosidase and bile salts deconjugation activities. Bifidobacterium bifidum strains showed the same behavior, although the values of the parameters investigated were slightly lower than those obtained for Lactobacillus acidophilus. On the other hand, it was demonstrated that Lactobacillus delbrueckii subsp. bulgaricus was the lactic acid starter species with the best probiotic characteristics among the starter species assessed. It was resistant to gastric juice and bile, and showed high values for β-galactosidase activity. On the other hand, lactic acid starter bacteria showed hydrophobicity values similar to or higher than those obtained for the strains of the Lactobacillus casei . According to the results found, the total probiotic value of a fermented dairy product should take into account not only the intestinal probiotic cultures used in the formulation but also the probiotic contribution of the lactic acid starter microflora.     

Safety assessment and antimicrobial properties of the lactic acid bacteria strains isolated from polish raw fermented meat products

Twenty-one strains of the genus Lactobacillus and the genus Pediococcus, isolated from Polish raw fermented meat products, were examined for the potential probiotic properties: resistance to simulated gastric and intestine conditions, safety assessment, and antimicrobial properties. Strains were resistant to gastric enzymes and low pH (3–6 log CFU/mL decrease) and intestinal enzymes and bile salts (1–3 log CFU/mL decrease). Most strains were resistant to gentamycin, streptomycin, vancomycin, tetracycline, ciprofloxacin, and kanamycin. Three of them (Lb. brevis BAL1, BAL10, and KL5) produced β-glucuronidase, which excludes them from qualifying as safe. Seven strains had the ability to produce bacteriocins or bacteriocin-like substances. Overall, strains Lb. brevis SCH6, Pd. pentosaceus BAL6, and KL14 revealed selected superior characteristics (resistance to the gastrointestinal conditions, safety assessment, and antimicrobial properties) as compared to the other LAB strains investigated, which made them a viable bioprotective culture that can be inoculated in raw fermented meat products as starter cultures.     

A survey of lactic acid bacteria for enzymes of interest to oenology

Isolates from wine-associated genera of lactic acid bacteria (LAB), including Lactobacillus , Oenococcus and Pediococcus , were examined for enzymatic properties that could be of value in the production and processing of wine. Up to 438 combinations of bacterial isolates and substrates were examined. Across the 50 isolates investigated, all were found to hydrolyse esters, with the greatest activity being seen amongst the oenococci followed by the lactobacilli and pediococci. Lipase activity was restricted to three Lactobacillus isolates, while all tested isolates displayed tannase activity. Cellulase, β-glucanase and lichenase activities were observed for almost all Pediococcus and Lactobacillus isolates, while such activities were seen for only a minority of oenococci. No degradation of the xylan substrate was detected. Once confirmed under winelike conditions, our findings will help define potentially interesting genera of LAB for winemaking.     

降胆固醇乳酸菌的筛选、鉴定及生长特性

从香肠、腊肉、泡菜、酸奶等传统发酵食品中获得的42株乳酸菌,应用不同胆固醇源的高胆固醇MRS-broth测定其降胆固醇能力,从中筛选出降胆固醇能力较高的6株菌,分别为CM7,S9,P5,P9,Y1,P215菌株。其中P215菌株具有较好的耐酸性、一定的胆盐耐受力和较高胆固醇降解率。结合形态学、生理生化特性和16S rDNA序列同源性分析,P215菌株被鉴定为植物乳杆菌(Lactobacillus plan-tarum)。并研究了P215菌株在添加鸡蛋黄和化合物胆固醇的MRS-broth中的生长曲线、pH值变化及胆固醇降解率。结果表明,P215菌株在高胆固醇MRS中2 h后进入对数生长期,10 h后进入稳定期,22 h后逐渐进入衰退期。     

新疆哈萨克酸马奶中功能性乳酸菌株的筛选、鉴定及功能评价

摘 要: 目的 从新疆哈萨克传统发酵酸马奶中筛选和鉴定益生性性乳酸菌,并探究其胃肠道消化耐受性和抗氧化潜力。方法 通过稀释涂布平板法和生理生化鉴定来分离纯化乳酸菌属,利用耐酸性和耐胆盐性筛选出潜在的胃肠道消化耐受性强的候选菌株,采用体外模拟消化、硫酸铁铵比色法和TG试剂盒评估候选菌株的胃肠道存活率、降胆固醇能力和降甘油三酯能力。同时,通过DPPH自由基清除能力、ABTS阳离子自由基清除能力和铁还原能力测试候选菌株的抗氧化潜力,并与德式乳杆菌保加利亚亚种(Lactobacillus delbrueckii subsp. bulgaricus)进行比较分析。最后,采用16S rRNA高通量测序对候选菌株进行精确鉴定。结果 从新疆哈萨克传统发酵酸马奶中分离纯化出96株菌株,40株被鉴定为乳酸菌属。10株候选菌株表现出较高的耐酸性和耐胆盐性,并被鉴定为鼠李糖乳杆菌(Lactobacillus rhamnosus)、植物乳杆菌(Lactobacillus plantarum)、戊糖乳杆菌(Lactobacillus pentosus)和副干酪乳杆菌(Lactobacillus paracasei)。其中,M2菌株（L. rhamnosus）表现出最佳的益生特性,胆固醇和甘油三酯降解率高,模拟胃肠液中存活率高,对DPPH和ABTS自由基的清除能力显著高于德式乳杆菌保加利亚亚种。结论 本研究成功从新疆哈萨克传统发酵酸马奶中筛选鉴定出高耐受性、高抗氧化性的L. rhamnosus M2,为发掘和利用酸马奶中的功能性益生菌提供了理论依据。     

Stability of microencapsulated lactic acid bacteria under acidic and bile juice conditions

The probiotic strains Lactobacillus brevis CCMA1284 and Lactobacillus plantarum CCMA0359 were microencapsulated by spray drying using different matrices – whey powder (W), whey powder with inulin (WI) and whey powder with maltodextrin (WM). Viability of the microencapsulated strains in acid and bile juices and during 90 days of storage (seven and 25 °C) was evaluated. The two strains exhibited high encapsulation efficiency (> 86%) by spray drying. The different matrices maintained L. plantarum viability above six log CFU g⁻¹ at 7 °C for 90 days, whereas similar results for L. brevis were observed only for W. The use of inulin as matrix of encapsulation did not enhance bacterial viability in the evaluated conditions. In general, the use of W and WM as matrices was effective for L. plantarum viability. However, only W was effective for L. brevis in the evaluated conditions. The spray drying technique was successfully adopted for the encapsulation of L. plantarum CCMA0359 and L. brevis CCMA1284 strains.     

Probiotic lactic acid bacteria from Kung‐Som: isolation,screening, inhibition of pathogenic bacteria

Lactic acid bacteria (LAB) were isolated from Kung‐Som at various fermentation periods. Only ten strains, named D2SM22, D6SM3, D6SM24, D6SM26, D8SM21, D10SM5, D10SM11, D10SM16, D10SM20 and D16SM26 showed a survival rate of more than 50% under the simulated gastric juice. After being subjected to simulated gastric juice, four strains (D6SM3, D8SM21, D10SM16 and D10SM20) showed a survival rate of more than 50% in simulated small intestinal juices. Growth of strain D6SM3, D8SM21 and D10SM16 under micro‐aerobic and anaerobic conditions was not different. Tested pathogenic strains (Escherichia coli, Staphylococcus aureus, Bacillus cereus, Vibrio parahaemolyticus and Salmonella sp.) were inhibited by probiotic LAB. However, none of strains could produce bacteriocins. All strains were identified as Lactobacillus plantarum. No differences in pH, acidity, LAB count and liking scores between Kung‐Som produced with starter culture and conventional method were observed (P > 0.01).     

乳酸菌的益生功能及作用机制研究进展

乳酸菌类益生菌是功能性食品的主要生理活性成分之一,其益生作用已经成为食品科学和临床医学领域的研究热点。本文就近年来乳酸菌改善乳糖不耐症、防治腹泻和消化性溃疡、提高机体免疫力等益生功能和作用机制的研究进展做一综述,并对研究前景提出展望,以期为我国乳酸菌的开发应用奠定基础。      

Screening of lactic acid bacteria and bifidobacteria for potential probiotic use in Iberian dry fermented sausages

The purpose of this study was to select lactic acid bacteria and bifibobacteria strains as potential probiotic cultures during the processing of Iberian dry fermented sausages. A total of 1000 strains were isolated from Iberian dry fermented sausages (363), and human (337) and pig faeces (300) in different culture media. Around 30% of these strains, mainly isolated from Iberian dry fermented sausages in LAMVAB agar, were pre-selected for testing as potential probiotics by their ability to grow adequately at the pH values and NaCl concentrations of these meat products during the ripening process. Of the in vitro investigations used to predict the survival of a strain in conditions present in the gastro intestinal tract, exposure to pH 2.5 showed itself to be a highly discriminating factor with only 51 out of 312 pre-selected strains resisting adequately after 1.5h of exposure. All acid-resistant isolates identified as lactobacilli originated from human faeces (Lactobacillus casei and Lactobacillus fermentum) and pig faeces (Lactobacillus reuteri, Lactobacillus animalis, Lactobacillus murinus, and Lactobacillus vaginalis). Pediococcus acidilactici strains were isolated from Iberian dry fermented sausages and pig faeces, whereas the greatest number of Enterococcus strains were identified as Enterococcus faecium, with this species being isolated from Iberian dry fermented sausages, and human and pig faeces. Most of these strains are promising probiotic meat culture candidates suitable for Iberian dry fermented sausages.     

降胆固醇乳酸菌鉴定及其在体外模拟胃肠环境中抗性研究

一株源于四川泡菜的具有降胆固醇能力的乳酸菌p5经形态学、生理生化特征和16SrDNA序列分析,鉴定为植物乳杆菌(Lactobacillus plantarum p5).在体外模拟胃肠环境中的抗性研究结果表明,p5具有较强耐酸能力,pH值为2.0时,2h活菌数保持在106cfu/mL;pH值为2.5时,4h内活菌数仍可保持在106cfu/mL,pH值为3.0～3.5时,p5 6h内活菌数可保持在106cfu/mL;p5具有耐高浓度胆汁盐的能力,在0.1%胆汁盐MPS中,p5表现出生长趋势,在0.2%～0.5%胆汁盐MRS中,p5活菌数下降急速,但6h后活菌数能保持在105cfu/mL;p5对肠炎沙门氏菌、大肠杆菌、铜绿假单胞杆菌、金黄色葡萄球菌等肠道致病菌有明显抑制作用.p5可望作为食品工业用菌种的资源.