活性酸乳中每种益生菌总数的同时计数法

益生菌酸奶的营养作用和保健功能决定于成品中必须含有一定数量级的活性益生菌数.本实验通过研究分析活性酸奶中嗜热链球菌、保加利亚乳杆菌、嗜酸乳杆菌、双歧杆菌、鼠李糖乳杆菌(LGG菌)、干酪乳杆菌等乳酸菌在BBL.平板培养基上的菌落特征及菌体形态,提出了一种可同时准确计数每种益生菌总数的新方法,该方法可直观地观察到各种益生菌的生长活度,免除了传统方法计数不同益生菌总数要用不同培养基的繁琐,为快速鉴定益生菌酸奶品质好坏和保健功能活性高低提供了检测依据.     

嗜酸乳杆菌、双歧杆菌和干酪乳杆菌的选择性计数

介绍了干酪乳杆菌、嗜酸乳杆菌和双歧杆菌的选择性计数方法。LC培养基只能计数干酪乳杆菌,MRS-水杨素（或山梨醇）培养基可以计数嗜酸乳杆菌和干酪乳杆菌;而MRS培养基可以计数这3种益生菌,通过减法原则从嗜酸乳杆菌、干酪乳杆菌和双歧杆菌混合物中单独计数。另外,MRS-NNLP培养基也可用于选择性计数双歧杆菌。     

发酵奶中乳酸菌菌种检出及活菌计数调查

目的分析北京市场发酵奶(酸奶)在保质期内的乳酸菌数及乳酸菌菌种的检出率。方法对11个酸奶厂家的20种不同酸奶产品进行乳酸菌活菌计数及所用菌种的检验。结果在保质期间,双歧杆菌和嗜酸乳杆菌检出率分别为23.08%和27.27%;保加利亚乳杆菌与嗜热链球菌分别为72.22%和94.44%。在保质期末,嗜热链球菌的平均活菌数为3.23×106CFU/ml,保加利亚乳杆菌为4.17×105CFU/ml,双歧杆菌为1.12×104CFU/ml,嗜酸乳杆菌为1.32×104CFU/ml。结论酸奶中嗜热链球菌和保加利亚乳杆菌的检出率及活菌数均高于双歧杆菌和嗜酸乳杆菌。     

货架期内酸乳益生菌菌数与酸度变化研究

对货架期内酸乳益生菌菌数及酸度变化进行分析,为合理的储藏和饮用提供理论依据.采用MRS和MC培养基对益生菌进行厌氧培养,通过菌落形态特征和生化反应结果对酸乳中德氏乳杆菌保加利亚亚种、嗜热链球菌、嗜酸乳杆菌和双歧杆菌分别进行计数,结果酸乳中益生菌总菌数及双歧杆菌在10 d内4℃下存放比常温存放降低速度慢一个数量级,与存放期间益生菌活动导致酸度增加存在密切关系.     

双歧酸乳最佳发酵条件的研究

双歧杆菌作为一种益生菌,其促进人体健康的有益作用越来越受到人们的重视,双歧杆菌乳制品利用双歧杆菌的益生作用在功能性乳制品的研发过程中也占有重要的一席之地.该文主要研究双歧杆菌酸乳的发酵条件,利用正交试验优化双歧杆菌与乳酸菌混合发酵的工艺条件,确定双歧杆菌和乳酸菌在牛乳中混合发酵的适宜接种量4％、发酵温度40℃、菌种配比(保加利亚乳杆菌∶嗜热链球菌∶双歧杆菌)3∶2∶1.     

混合制剂中快速计数双歧杆菌鉴别培养基的研究

研制了一种混合制剂中快速计数双歧杆菌鉴别培养基。用添加X-Gal的改良MRS培养基和厌氧胶法对4种标准双歧杆菌(长双歧杆菌、短双歧杆菌、青春双歧杆菌、两歧双歧杆菌)和2种标准乳酸菌(保加利亚乳杆菌、嗜热链球菌)分别单独培养、混合培养,结果在X-Gal培养基上,双歧杆菌单独培养及与乳酸菌混合培养双歧杆菌均为白色菌落或浅蓝色菌落,而乳酸菌为蓝色菌落。结果表明,在X-Gal培养基上双歧杆菌和乳酸菌有明显的鉴别性,可用于双歧杆菌和乳酸菌混合制剂的菌落鉴别计数。     

益生菌发酵牛初乳对致病菌抑制作用的研究

研究了益生菌发酵牛初乳对致病性大肠杆菌及幽门螺旋杆菌的抑制作用。结果表明,初乳经益生菌发酵,导致初乳pH值降低,初乳IgG活性也相应降低,在pH值为4.6时,IgG活性仅为初乳的25%。不同益生菌发酵初乳在不同pH值对大肠杆菌及幽门螺旋杆菌均有抑制作用,且嗜酸乳杆菌发酵初乳抑制作用最强,对大肠杆菌的抑制率最高达83.2%,对幽门螺旋杆菌抑菌圈直径最大达17.2mm,达到高度敏感,分别较初乳的抑制作用提高47.52%和52.21%。不同益生菌发酵初乳的抑菌作用依次为嗜酸乳杆菌>双歧杆菌>混合乳酸菌>德氏乳杆菌保加利亚亚种>嗜热链球菌。     

超氧化物歧化酶益生菌发酵酸奶的研究

本文研究了在不同的益生菌发酵剂配比条件下酸奶的品质和口感.双歧杆菌:嗜酸乳杆菌:保加利亚乳杆菌:嗜热链球菌比例为(10∶4∶2∶2)用于酸奶的混合发酵生产,可以使双歧杆菌活菌数达到1.5×108cfu/ml、嗜酸乳杆菌活菌数达到3.1×108 cfu/ml;采用添加低聚木糖等益生元,可以促进双歧杆菌的活菌数目提高;发酵后在LABS酸奶中添加SOD,可保持其在酸奶中较高的酶活力.SOD-LABS益生菌酸奶在4℃保存21d,SOD酶活性能保持75%以上.     

一种双歧杆菌复合乳饮料的研制

酸乳饮料因其独特的生理功能而备受人们的青睐,尤其是益生菌饮料的开发和研制更是成为研究的热点,但是其稳定性问题与口感的矛盾一直是困扰广大研究者的难题.本研究以发酵生产的嗜酸乳杆菌发酵乳、双歧杆菌发酵乳、增香普通酸乳为原料,通过复配得到一种长双歧益生菌饮料.采用CMC、果胶、黄原胶、单甘酯四种添加剂对其稳定性进行了优化.并确定了其最佳配方为:80%发酵乳、12%的水、8%的蔗糖、CMC 0.5%、果胶0.1%、黄原胶0.1%、单甘酯0.15%.结果表明,所得到的益生菌饮料不仅具有酸乳特有的口感,还具有了双歧杆菌、嗜酸乳杆菌和乳酸菌的保健功能,酸乳饮料的稳定性问题也得到了一定的提高.本试验有效的解决了酸乳饮料稳定性及口感的矛盾,从而能为益生菌酸乳饮料的开发提供一定的指导.     

复合益生菌发酵剂制备乳酸菌饮料的研究

以复合益生菌(嗜热链球菌、保加利亚乳杆菌、嗜酸乳杆菌和双歧杆菌)为发酵剂,研制功能性乳酸菌饮料。通过正交试验得到乳酸菌饮料最佳配方:发酵乳添加量25%、水65%、白砂糖10%、CMC 0.10%、黄原胶0.15%、果胶0.10%,调节pH值为3.85条件下,所得到的乳酸菌饮料稳定性好、口感爽滑细腻、酸甜适中,蛋白质含量、酸度、总固体含量等指标均符合国家质量标准,所含活乳酸菌菌数达3.2×109cfu/mL。     

益生菌豆酸乳发酵条件的优化

豆酸乳是将大豆磨浆后与牛乳混合经乳酸菌发酵而赋予特殊风味的产品,但尚未有仅用嗜酸乳杆菌和两歧双歧杆菌2株菌来发酵益生菌豆酸乳的报道。对碳源、生长促进因子、稳定剂和温度等发酵条件进行优化,实验结果表明:在豆水比为1:8、牛乳含量为30%的豆浆牛乳混合物中添加4.0%的蔗糖、0.3%的葡萄糖、0.6%的低聚果糖、0.8%的BY-H-260,在无菌条件下添加0.005%的嗜酸乳杆菌菌粉和0.015%的两歧双歧杆菌菌粉,在42℃条件下发酵5～5.5 h,酸度可达70～75°T(pH为4.0左右),活菌数可达108cfu/mL级,组织状态良好。     

抗坏血酸对发酵豆乳中嗜酸乳杆菌存活力影响的研究

本研究采用嗜酸乳杆菌和传统菌混合发酵制作酸豆乳的工艺,探讨在培养基中添加抗坏血酸对提高嗜酸乳杆菌在发酵酸豆乳成品中存活力的影响。实验结果表明,抗坏血酸可以促进酸豆乳中嗜酸乳杆菌的生长。通过对温度、发酵剂添加量及抗坏血酸添加量三个因素进行正交试验确定感官品质良好、活菌数量较高的组合为温度39℃、发酵剂添加量6%,抗坏血酸添加量0.01%,在此条件下生产的发酵酸豆乳质地细腻、酸甜适口,嗜酸乳杆菌活菌数达到6.3 × 108CFU/ml.     

Preliminary investigation of the combined effect of heat treatment and incubation temperature on the viability of the probiotic micro-organisms in freshly made yogurt

The combined effects of heat treatment and incubation temperature were studied on the viability and fermentation time of probiotics in ABY 1 probiotic yogurt ( Lactobacillus acidophilus , Bifidobacterium spp. and yogurt bacteria). Three levels of heat treatment (85°C for 30 min, 95°C for 5 min and 95°C for 15 min) and three levels of incubation temperature (37, 40 and 44°C) were selected. At the end of fermentation, the maximum viability of probiotics (for both L. acidophilus and Bifidobacterium spp . ) was observed when the milk was heated at 95°C for 15 min and incubated at 37°C. Incubation time was only affected by the incubation temperature and, at 37°C, the longest incubation time of about 6 h was needed to achieve the highest viable counts of L. acidophilus and Bifidobacterium spp.     

Isolation, identification and characterisation of the dominant microorganisms of kule naoto: the Maasai traditional fermented milk in Kenya

From 22 samples of kule naoto, the traditional fermented milk products of the Maasai in Kenya, 300 lactic acid bacterial strains were isolated and phenotypically characterised by their ability to ferment different carbohydrates and by additional biochemical tests. Lactic acid bacteria (LAB), especially the genus Lactobacillus, followed by Enterococcus, Lactococcus and Leuconostoc, dominated the microflora of these samples. The major Lactobacillus species was Lactobacillus plantarum (60%), with a lower frequency of isolation for Lactobacillus fermentum, Lactobacillus paracasei and Lactobacillus acidophilus. Most strains produced enzymes such as beta-galactosidase and peptidases, which are of relevance to cultured dairy product processing, and exhibited similar patterns of enzymatic activity between species. Enterobacteriaceae could not be detected in 15 out of 22 samples (detection level 10(2)/ml). Conversely, yeasts (detection level 10(1)/ml) were detected in those samples in which Enterobacteriaceae were not found. The pH values of all these samples were < 4.5.     

紫苏油对益生菌的增殖作用研究

通过体外厌氧培养的方法,研究了紫苏油对嗜酸乳杆菌、双歧杆菌两种益生菌的体外增殖作用。结果表明:紫苏油添加量为3%时,嗜酸乳杆菌的增殖数达到最大值,为1.292;当紫苏油添加量为1%时,双歧杆菌的增殖数达到最大值,为1.352。紫苏油具有一定的促进益生菌增殖作用。     

Starter cultures employed in the manufacture of biofermented milks

The market for fermented milks is expanding as more consumers become interested in the possible health aspects of the product. This paper reviews the types of bacteria that are currently being used in the manufacture of biofermented milks. The requirements of a starter culture in terms of ability to ferment milk to a stable product and to provide the necessary sensory properties for consumer demands are outlined. The paper also discusses and highlights some of the problems encountered in developing milks for the health market using probiotic organisms such as Lactobacillus acidophilus and species of Bifidobacterium.     

Proteolytic profiles and angiotensin-I converting enzyme and alpha-glucosidase inhibitory activities of selected lactic acid bacteria

ABSTRACT:  This study was conducted to examine the growth, proteolytic profiles as well as angiotensin-I converting enzyme (ACE) and α-glucosidase (α-glu) inhibitory potentials of selected strains of lactic acid bacteria (LAB). Two strains each of yogurt bacteria ( Streptococcus thermophilus —1275 and 285, and Lactobacillus delbrueckii ssp. bulgaricus —1092 and 1368), and probiotics ( L. acidophilus —4461 and 33200, and L. casei —2607 and 15286, and 1 strain of Bifidobacterium longum 5022), were cultivated in reconstituted skim milk (RSM) at 37 °C and their proteolytic profiles and ACE as well as α-glu inhibitory activities were determined. Among all the strains of lactic acid bacteria studied, yogurt bacteria grew very well, with the exception of L. delbrueckii ssp. bulgaricus 1368 which showed a slower growth during the initial 3 h of incubation. The growth pattern corresponded well with the decrease in pH for the organisms. All the organisms showed an increase in proteolysis with time. The variations in proteolytic capabilities translated into corresponding variations in ACE inhibitory potential of these organisms. Bifidobacterium longum 5022 showed the highest ACE inhibitory potential followed by L. delbrueckii ssp. bulgaricus 1368, L. casei 15286, S. thermophilus 1275, and L. acidophilus 4461. Organisms with high intracellular enzymatic activities grew well. Also, aminopeptidases of strains of L. acidophilus 4461 and S. thermophilus 1275 that could better utilize proline containing substrates showed enhanced ACE inhibitory potential. Lactic acid bacteria possessed the ability to inhibit α-glu activity, which endowed them an antidiabetic property as well.     

益生菌发酵蓝莓花色苷的代谢规律

选用嗜热链球菌、两岐双歧杆菌、植物乳杆菌进行纯种发酵含有蓝莓花色苷提取液的培养液,考察了益生菌发酵过程中活菌数、体外抗氧化性、有机酸、单体花色苷和酚酸等组分的变化情况。结果表明,发酵48 h后,三种益生菌的活菌数均增至8.0 lg CFU/mL左右,两岐双歧杆菌的活菌数最高(P<0.05),发酵后不同菌株发酵样的ABTS+·清除能力显著提升(P<0.05),其中两岐双歧杆菌发酵样品抗氧化能力最强(P<0.05);但植物乳杆菌发酵样品中乳酸含量最高(P<0.05);发酵过程中单体花色苷含量呈下降趋势,两岐双歧杆菌发酵样品花色苷组分与其它两株菌发酵的样品差异较大;绿原酸、对香豆酸和咖啡酸的含量总体呈现下降趋势,而没食子酸、丁香酸和阿魏酸含量呈上升趋势,主成分分析图中三株益生菌发酵样的分布差异较大。以上结果为进一步解释益生菌发酵代谢花色苷的机理提供了参考。     

蔬菜汁的乳酸菌发酵

为制备不含任何动物性来源成分的纯植物性的乳酸菌发酵产品,采用双歧乳杆菌、植物乳杆菌、保加利亚乳杆菌、嗜酸乳杆菌4种乳酸菌,在豆角、香菇、番茄、青瓜、胡萝卜和包菜6和蔬菜培养液中进行发酵。实验结果证明,4种乳酸菌可以在不添加其他营养物质的纯蔬菜培养液正常生长,但是不同菌种适合的蔬菜培养液也不相同,且混合蔬菜培养液培养效果要好于单一蔬菜培养液。番茄和青瓜混合培养液适合双歧乳杆菌生长,包菜和青瓜混合培养液适合植物乳杆菌生长,包菜和番茄混合培养液适合保加利亚乳杆菌生长,豆角和青瓜混合培养液适合嗜酸乳杆菌生长。蔬菜的乳酸菌发酵产品,在4℃下冷藏2周后,4种菌体的存活率均在106CFU/mL以上。在不添加其他营养物质的条件下,蔬菜汁可以用来生产活性乳酸菌产品,满足素食主义者、乳糖不耐症者的消费需求。     

两歧双歧杆菌与嗜酸乳杆菌微生态制剂的工业化生产工艺研究

研究了两歧双歧杆菌和嗜酸乳杆菌双联微生态制剂的工业化生产工艺。对发酵培养基及发酵条件进行了研究和优化，并确定了发酵奶的冷冻干燥工艺条件。冻干后的产品中两歧双歧杆菌和嗜酸乳杆菌的活菌数均达到了10^9-10^10g^-1，而且在冻干工艺条件下，发酵产物中的各种活性成分得以最大限度地保存下来，使产品可以达到作为微生态制剂应用的相关标准。