对酸奶中益生菌应用种类和含量的分析

从益生菌的使用状况出发,为研发新的益生菌酸奶产品提供依据。采用GNPD数据库分析国内市场上新品益生菌酸奶的益生菌添加种类,并通过选择性培养方式检测在售的几款益生菌酸奶产品中益生菌的含量。通过GNPD搜索到的61份新品益生菌酸奶中,添加嗜酸乳杆菌和双歧杆菌的分别占总量的52.5%和67.2%,且嗜酸乳杆菌和双歧杆菌组合添加的比例达到45.9%。对几款益生菌酸奶产品中益生菌含量进行检测,益生菌活菌含量在货架期内为106~108CFU/g。旨在加强对国内市场上现有益生菌酸奶产品的分析,本实验为国内首次对益生菌酸奶产品中益生菌菌种的应用状况进行分析,为益生菌酸奶的研发提供参考。     

益生菌素对嗜酸乳杆菌LA-5生长的影响

脱脂乳(110 g/L)中分别添加3种益生菌素(菊粉、麦芽低聚糖和低聚异麦芽糖)增殖发酵嗜酸乳杆菌LA-5,研究这3种益生菌素对LA-5菌株生长的影响,如活菌数、酸乳黏度、双乙酰含量、酸度、pH等的变化等指标.研究结果表明:低聚异麦芽糖对LA-5生长促进作用最佳,12h左右CFU值达到最高,为2.37×108 CFU/mL,其酸乳产品双乙酰含量＜0.2 mg/L,无不愉快气味;其酸度在16h时达到58.87.T,为添加3种益生菌素中最高.     

不同蛋白水解物对益生菌在乳中生长的影响

对不同来源的蛋白水解物进行筛选，向乳中添加筛选出的蛋白水解物可以明显的促进某些益生菌的生长和产酸，但是对传统乳酸菌影响不显著。确定最适添加量为0．5％。当益生菌同传统乳酸菌进行混合发酵时，添加蛋白水解物可以显著提高益生菌活菌数。在进一步的14d保藏试验中，与空白对照相比可以提高大多数益生菌的存活率，保证了益生菌产品具有正常的生理功效。     

双歧杆菌在冰淇淋中的应用

对双歧杆菌冰淇淋的生产工艺条件及各工艺条件对双歧杆菌活菌数的影响作了研究和探讨。实验表明，我们筛选的双歧杆菌可以应用到冰淇淋中，使产品达到一定数量的活菌数。而且除均质之外的加工条件对双歧杆菌的存活均无明显影响。所制得的冰淇淋是一很好的保健饮品。     

益生菌有多种神奇

益生菌对消费者已经不是新鲜名词了。在超市冷柜里随便拿起一瓶酸奶,几乎都可以看到上面标有“富含乳酸菌”的说明。通过电视铺天盖地的广告,人们都知道益生菌是个“好东西”,但究竟什么是益生菌,益生菌对人体有哪些好处？面对着标有“LGG”、“AB”、“BB”等各种令人看不懂的益生菌代号的酸奶制品,恐怕就很少有人能说得上来了。益生菌,一般是指寄生在人体肠道,能抑制有害菌在肠内的繁殖、促进肠道运动的有益菌,包括双歧杆菌、嗜热链球菌、嗜酸乳杆菌等种类。目前含有益生菌的产品包括：含益生菌的酸牛奶、酸乳酪、酸豆奶以及含多种益生菌的口服液、片剂、胶囊、粉末剂等等。对于益生菌的保健效果,目前国际学术界的看法并不统一。支持派从临床试验出发,认为益生菌对人体是有益的;而反对派则认为,学界仅仅对益生菌能帮助消化、增强肠胃功能达成共识,但益生菌酸奶宣传的益生菌概念模糊,对其功能缺乏有力的科学研究证据,存在商业炒作嫌疑。     

多菌种发酵生产保健型酸奶的研制

通过对保加利亚乳杆菌、嗜酸乳杆菌、干酪乳杆菌、双歧杆菌等九种乳酸菌进行复配，用正交实验，对多菌株混和发酵条件作了初步探讨，从风味、活菌数数量上确定混和菌种的最佳组合，为生产保健作用更好的新型酸奶打下基础。     

牛羊乳促嗜酸乳杆菌增菌发酵差异性及冷藏存活率比较研究

益生菌的活菌数量是衡量益生菌产品及制剂的营养价值和保健功能的主要指标之一。本研究以嗜酸乳杆菌为发酵剂分析比较牛乳发酵奶和羊乳发酵奶中嗜酸乳杆菌增菌发酵的活力差异,及在冷藏期活菌数量的变化趋势,探讨了牛羊乳在促进嗜酸乳杆菌发酵方面的差异性及在冷藏期存活率变化规律。结果表明:嗜酸乳杆菌在羊乳基质中表现为较好的增菌发酵效能,总活菌数为1.66×1010CFU/mL,大于牛乳基质中的总活菌数3.02×109CFU/mL;羊乳发酵奶和牛乳发酵奶在21d贮藏期内嗜酸乳杆菌的活菌数均维持在较高活力水平,而在21～26d的贮藏期内,其存活性显著降低(p<0.05),存活率分别为84.15%和84.39%。由此说明羊乳基质促嗜酸乳杆菌增菌发酵效能更佳,牛、羊乳发酵奶在贮藏期活菌数变化规律基本一致。     

牛羊乳促嗜酸乳杆菌增菌发酵差异性及冷藏存活率比较研究

益生菌的活菌数量是衡量益生菌产品及制剂的营养价值和保健功能的主要指标之一。本研究以嗜酸乳杆菌为发酵剂分析比较牛乳发酵奶和羊乳发酵奶中嗜酸乳杆菌增菌发酵的活力差异,及在冷藏期活菌数量的变化趋势,探讨了牛羊乳在促进嗜酸乳杆菌发酵方面的差异性及在冷藏期存活率变化规律。结果表明:嗜酸乳杆菌在羊乳基质中表现为较好的增菌发酵效能,总活菌数为1.66×1010CFU/mL,大于牛乳基质中的总活菌数3.02×109CFU/mL;羊乳发酵奶和牛乳发酵奶在21d贮藏期内嗜酸乳杆菌的活菌数均维持在较高活力水平,而在21～26d的贮藏期内,其存活性显著降低(p<0.05),存活率分别为84.15%和84.39%。由此说明羊乳基质促嗜酸乳杆菌增菌发酵效能更佳,牛、羊乳发酵奶在贮藏期活菌数变化规律基本一致。      

双层包埋益生菌之检测技术及应用

经大豆蛋白及纤维素双层微包埋之益生菌可比一般不经包埋或单层包埋之益生菌具有更高之储存及热稳定性,且对胃酸、胆酸盐之耐受性及二次加工稳定性亦具有更好的效能.双层包埋益生菌因受包埋物质之保护作用,可耐受胃部酸性环境而于中性肠道中释放出來,因此在原料及产品质量检测时溶离缓冲溶液的组成、pH及震荡时间等皆会影响分析结果.但是此种双层包埋技术也同時影响活菌测试結果,使用传统技术往往无法将活菌适当释放,致使所得数据往往偏低,而不同方法间之分析结果差距可达10-100倍.本研究因此比较不同溶离条件,期能正确分析双层包埋之益生菌之总菌数.结果发现需使用含有介面活性剂之中性溶离缓冲溶液,並经适当震荡操作将包埋之乳酸菌充分释放始能得到稳定准确数值.其操作条件及相关参数关系应可成为未来类似乳酸菌产品检验之参考.而经此技术测试也证明双层包埋益生菌在实际应用上,如果汁、饮料、巧克力等食品中添加的确具有良好储存稳定性.     

活细胞传感仪在嗜酸乳酸杆菌培养过程中的应用

活细胞是嗜酸乳酸杆菌发酵过程的目标产物,但长期以来一直缺乏一种能快速、准确地检测发酵液中活细胞量的方法,本文引入了一种基于电容原理的活细胞量测量新方法,探讨了其在嗜酸乳杆菌培养过程中在线应用的可行性。研究结果表明,活细胞传感仪测定的活细胞数与平板活菌计数法测定的菌体浓度有非常好的线性关系,相关系数达0.9944,在相同的实验条件下,仪器测定数据具有较好的重复性,基于电容值计算出的比生长速率比基于CER、OUR计算出的比生长速率更可信。因此活细胞传感仪为嗜酸乳杆菌培养过程在线监测提供了一种简便、精确的方法。     

Improving the viability of Bifidobacterium bifidum BB-12 and Lactobacillus acidophilus LA-5 in white-brined cheese by microencapsulation

The viability of Bifidobacterium bifidum BB-12 and Lactobacillus acidophilus LA-5 microencapsulated by either an extrusion or an emulsion technique and used in white-brined cheese was monitored. Both microencapsulation techniques were effective in keeping the numbers of probiotic bacteria higher than the level of the therapeutic minimum (>10⁷ cfu g^?1). While the counts of probiotic bacteria decreased approximately 3 log in the control cheese in which probiotics were used as free cells, the decrease was more limited in the cheeses containing microencapsulated cells (approximately 1 log). Medium- and long-chain free fatty acid contents of the cheeses with immobilized probiotics were much higher than in the control cheese. Similarly, cheeses made with immobilized probiotics contained higher acetaldehyde and diacetyl levels than the control. Experimental cheeses containing microencapsulated probiotics were not different from the control cheese in terms of sensory properties.     

Effect of Microencapsulation on Viability of Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum BB-12 During Kasar Cheese Ripening

The viability of encapsulated Lactobacillus acidophilus LA-5 and Bifidobacterium bifidum BB-12 by emulsion or extrusion techniques in Kasar cheese was investigated. The microbiological, biochemical and organoleptic properties of cheeses were assessed throughout 90-day storage. Results showed that the viability of probiotic bacteria was maintained to a great extent by microencapsulation. No difference was noted between the two encapsulation techniques with regard to bacterial counts, proteolysis and organoleptical properties of the final products. Scalding caused a drastic decline in the counts of probiotic bacteria in all cheeses. Following scalding, while the numbers of nonencapsulated probiotic bacteria decreased continuously in the control cheese, the numbers of encapsulated bacteria remained well above the threshold for a minimum probiotic effect (10⁷ cfu/g).     

新疆酸乳中益生菌的筛选与鉴定

从新疆各地区牧民家自制的23个酸奶样品中筛选出的9株乳酸菌,其中有3株乳酸菌ALT-2-b、KS-3-a、KS-5-b具有较好的ACE抑制活性,2株乳酸菌HT-b和HT-e的胆固醇降解能力较强。ALT-1-a的蛋白质水解能力最好,其次是KS-3-a、KS-5-b、ALT-2-b。因此,KS-3-a、KS-5-b、ALT-2-b和ALT-1-a四株乳酸菌都是可以作为潜在的具有ACE抑制活性的益生菌。作为降解胆固醇的益生菌,乳酸菌HT-b和HT-e是值得研究探索的。     

TG酶和漆酶对双歧杆菌益生菌酸奶品质的影响

为了比较谷氨酰胺转氨酶(TG酶)和漆酶的添加对双歧杆菌益生菌酸奶感官、蛋白质交联及组织质构变化的影响,测定和分析了两种酶交联益生菌酸奶的游离氨基变化率、感官、质构、表观黏度、蛋白条带及微观结构,并添加阿魏酸改善漆酶酸奶的品质。结果表明:当TG酶用量增加时,TG酶交联酸奶的游离氨基变化率、感官得分和硬度显著增大(p<0.05),胶黏性、粘聚性及表观黏度先增大后减小(p<0.05),内聚性变化不显著(p>0.05),TG酶最佳用量为1.8 U/g;随着漆酶用量的增加,漆酶酸奶游离氨基变化率、感官得分、硬度、内聚性、胶黏性、粘聚性及表观黏度均先增大后减小(p<0.05),漆酶最佳用量为0.3 U/g;添加4.5 mmol/L的阿魏酸明显改善了漆酶交联酸奶的感官、质构及表观黏度;所有待测酸奶中均缺少β-lg条带,TG酶交联酸奶的κ-CN和β-CN条带消失,聚集成了新的蛋白质,而漆酶交联酸奶和阿魏酸+漆酶酸奶与对照及TG酶酸奶相比,分子量在14 kDa的蛋白条带明显变宽;经两种酶交联的酸奶,三维网络结构变得致密,TG酶交联酸奶的胶粒分布更均匀,网络结构更致密,且在漆酶交联酸奶中添加了阿魏酸后,相较于漆酶交联酸奶,蛋白胶束聚集的更紧密,从而得出,不同类型酶对牛奶乳蛋白质交联的催化作用不同,但均可改善酸奶的感官及食用品质。     

Effects of the addition of microencapsulated Bifidobacterium BB-12 on the properties of frozen yogurt

Samples of frozen yogurt were added with microcapsules containing Bifidobacterium BB-12 produced with different contents of carrier agents (reconstituted skim milk and inulin). The viability of this probiotic culture was evaluated, as well as the effect of addition of microcapsules on the chemical and rheological properties of frozen yogurt during 90 days of storage. The counts of bifidobacteria maintained practically constant in the samples added with the microcapsules, while the frozen yogurt added with free bacteria showed a decrease of about 34% after 90 days. The addition of the microcapsules increased the total solids content and the overrun values. The highest pH values were noted in the samples containing microcapsules produced with reconstituted skim milk. All the melted frozen yogurts showed non-Newtonian behavior with shear thinning characteristics. The samples added with microcapsules had greater apparent viscosity and those added with microcapsules produced with inulin showed a larger hysteresis area at the end of storage period.     

Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults

This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10⁹ cfu/100 g of BB-12 and LA-5 and 40 mg of green tea extract) and 3. Yoptimal-10 (10¹⁰ cfu/100 g of BB-12, 10⁹ cfu/100 g of LA-5 and 40 mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10⁷ cfu/100 g) and Streptococcus thermophilus (10¹⁰ cfu/100 g). The quantitative PCR (qPCR) results showed that there were significant increases (P = 0.02) in bifidobacteria counts with the Yoptimal treatment as compared to baseline. The fecal numbers of B. animalis subsp. lactis and LA-5 significantly increased in the two probiotic treatments compared to the placebo treatment. Viable counts of fecal lactobacilli were significantly higher (P = 0.05) and those of enterococci were significantly lower (P = 0.04) after the intervention when compared to placebo. No significant difference was observed between treatments in volunteers' weight, waist girth, blood pressure, fasting plasma triglyceride and HDL-C concentrations, as well as cholesterol/HDL-cholesterol ratio. However, a significant increase in plasma cholesterol levels was observed in the placebo group (P = 0.0018) but the levels remained stable in the two probiotic yoghurt groups. These results show that probiotic strains supplemented in the form of yoghurt remain active during gut transit and are associated with an increase in beneficial bacteria and a reduction in potentially pathogenic bacteria. This trial was registered at clinicaltrials.gov as NCT00730626.     

TaqMan-MGB探针荧光定量聚合酶链式反应法检测酸奶制品中动物双歧杆菌BB-12

摘 要：【目的】本研究拟建立一种快速、高灵敏性检测和定量酸奶中动物双歧杆菌BB-12的方法。【方法】设计动物双歧杆菌BB-12的16SrRNA序列的MGB探针,利用荧光定量PCR技术,构建目标序列的过表达载体,提取质粒进行标准曲线的制作,最后进行市售酸奶样品检测,定量酸奶中BB-12菌株的数量。【结果】所有载体标准品均产生显著的荧光增幅,Ct值介于16～20之间;而以其他酸奶制品添加菌以及大肠杆菌样品DNA为模板则无荧光扩增信号。在检测灵敏度方面,BB-12载体可被稳定检出的质量浓度低至0.0000584 ng/μL,Ct值平均数为28.73,即检测灵敏度低至为0.05 pg。制作的标准曲线线性良好,扩增效率E为0.39,判定系数R2=0.9999。市售酸奶样品检测特异性好、灵敏度高及定量结果准确。【结论】通过特异性的TaqMan-MGB探针进行荧光定量PCR检测可实现在酸奶中对BB-12菌种的检测及定量。     

菊芋浓缩液对酸乳中益生菌的生长和功能的影响研究

将菊芋浓缩液按不同的量添加到脱脂鲜乳中,考察了复合酸乳的酸度和菌数以及菌体的生长情况,结果表明凝乳时的酸度和菌数都随着添加量的增多而增大;在以上实验的基础上,同时以菊芋复合酸乳对小鼠进行灌胃,结果发现以菊芋复合酸乳灌胃小鼠的肠道乳杆菌数比纯酸乳灌胃组小鼠和空白组都有提高,说明添加菊芋浓缩液的酸乳促进了小鼠肠道乳酸菌的增殖.     

应用萌发大豆生产益生菌发酵豆乳的研究

通过SDS-PAGE电泳分析大豆萌发过程中大豆蛋白亚基组成含量的变化,确定以萌发至2³cm长的大豆作为主要原料,经瑞士乳杆菌、保加利亚乳杆菌和嗜热链球菌组合发酵制成发酵豆乳。研究表明,与非萌发大豆制成的发酵豆乳相比,以萌发大豆制成的发酵豆乳口感和质构均得到明显改善,硬度和脆度分别下降了38.61%和38.85%,粘附性从-86.779g·s增加至-52.172g·s,口感更细腻柔软粘稠,与发酵纯牛乳相接近。