益生菌粉剂产品的稳定性研究

检测不同贮存条件下益生菌粉剂产品中的活菌数.结果发现:经过3个月的恒温加速试验,样品活菌数急剧下降5个数量级;在24个月的室温摆放试验中,样品活菌数的下降幅度不超过2个数量级;低温存放试验中产品的活菌数含量基本保持稳定.可见,室温摆放试验能客观体现活菌产品的实际贮存及货架销售情况,对评价益生菌粉剂产品的稳定性和和预测其保质期具有指导意义.     

弱后酸化酸奶发酵剂的筛选及应用

选取3种酸奶发酵剂09D-B、YT-A和YT-B,制成酸奶,测定不同温度条件下3种酸奶样品在发酵过程和保质期内的酸度、黏度、pH值和乳酸菌活菌数的变化趋势,研究不同发酵剂对酸奶产品品质的影响。结果表明,发酵剂YT-A的后酸化能量最弱,在4℃冷藏20 d后,酸度仅上升了9°T,产品黏度较高,在冷藏条件下乳酸菌活菌数为4.6×107个/mL,在4℃冷藏和20℃常温贮存过程中,产品的感官状态和组织状态均优于发酵剂09D-B和YT-B。     

益生菌BB-46及LA-5在酸奶中的应用

首先介绍了我国益生菌酸奶的发展现状及趋势，然后通过试验研制出一种益生菌酸奶。从酸奶的发酵过程上严格控制，刚发酵结束产品总菌数高达10^9g^-1，尤其益生菌LA-5及BB-46活菌数在保质期内均达到10^9g^-1。以上、且该产品获得很好的感官质量。     

绿豆酸奶粉的加工工艺

对酸奶菌种进行耐热驯化,制备绿豆酸奶后,配以奶粉、麦芽糊精及保护剂等进行喷雾干燥制备绿豆酸奶粉,较好地保存了部分活菌数,延长了产品的保质期。     

绿豆酸奶粉的加工工艺

对酸奶菌种进行耐热驯化,制备绿豆酸奶后,配以奶粉、麦芽糊精及保护剂等进行喷雾干燥制备绿豆酸奶粉,较好地保存了部分活菌数,延长了产品的保质期。      

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。     

开菲尔发酵剂发酵特性研究

以三种开菲尔发酵剂和一种普通酸奶菌种为发酵剂,制作成发酵乳。通过监测四种发酵剂发酵过程的pH值变化趋势,以及在4 ℃冷藏过程中酸度、pH值、黏度、乳酸菌活菌数、酵母菌、口感等指标,分析开菲尔发酵剂与普通酸奶发酵剂的发酵特点及其产品在保质期内特性变化。结果表明,与普通酸奶菌种相比,开菲尔发酵剂凝乳时间较长,发酵时间约为12～20 h,在保质期内,酸度增长较为缓慢,黏度较低,乳酸菌活菌数较高,口感方面优于普通发酵剂酸奶。     

乳酸链球菌素对酸奶品质影响的研究

将Nisin按不同浓度的添加量添加到牛乳中制成酸奶,测定酸奶在发酵过程及4℃贮存过程中的酸度、粘度、pH、乳酸菌活菌数、霉菌以及酵母菌的变化趋势。结果表明,添加Nisin可有效抑制酸奶的后酸化,酸奶在保质期内酸度变化在68～78°T之间,pH在4.33～4.53之间,乳酸菌活菌数在2.1×106～2.08×108CFU/mL之间。添加Nisin延长了酸奶的发酵时间,酸奶在保质期内粘度较低,在抑制霉菌和酵母方面无差别。Nisin含量为60IU/mL时对酸奶品质影响不明显,可有效抑制酸奶后酸化进程,延长酸奶保质期。      

乳酸链球菌素对酸奶品质影响的研究

将Nisin按不同浓度的添加量添加到牛乳中制成酸奶,测定酸奶在发酵过程及4℃贮存过程中的酸度、粘度、pH、乳酸菌活菌数、霉菌以及酵母菌的变化趋势。结果表明,添加Nisin可有效抑制酸奶的后酸化,酸奶在保质期内酸度变化在68～78°T之间,pH在4.33～4.53之间,乳酸菌活菌数在2.1×106～2.08×108CFU/mL之间。添加Nisin延长了酸奶的发酵时间,酸奶在保质期内粘度较低,在抑制霉菌和酵母方面无差别。Nisin含量为60IU/mL时对酸奶品质影响不明显,可有效抑制酸奶后酸化进程,延长酸奶保质期。     

益生菌粉中活菌稳定性及其耐受模拟胃肠液的研究

为了解益生菌粉中的活菌稳定性,对6个市售益生菌粉产品中的益生菌存活数以及对模拟胃液、肠液及胃肠液的耐受性进行了分析.结果表明:6个产品中的活菌数与标识存在差异,产品E中活菌数最多,为10.19 lg CFU/g,产品B中活菌数最少,为6.47 lg CFU/g;20℃贮藏3个月后,产品F活菌数下降一个数量级,其他产品活...     

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.     

5L立瓶发酵制备益生菌直投式发酵剂及应用试验

对长双歧杆菌、保加利亚乳杆菌、嗜热乳酸链球菌在5 L立瓶中分别进行培养,确定了各自的发酵最适收获期,菌体收集后经制备所获得冷冻浓缩直投式发酵剂活菌数大于1010mL-1,冷冻干燥直投式发酵剂活菌数大于1011g-1。以制备的冷冻浓缩、冷冻干燥直投式发酵剂,进行牛乳发酵应用试验,生产的益生菌酸奶风味纯正、品质良好。     

不同发酵剂对黑枣酸奶品质的影响

使用不同益生菌组合制备黑枣酸奶,并探究不同益生菌组合对发酵和质构特性的影响。结果表明,不同益生菌组合会显著影响黑枣酸奶的理化指标和质构特性（P＜0.05）;相比传统酸奶发酵剂,强化植物乳杆菌、嗜酸乳杆菌和乳双歧杆菌（1∶1∶1）发酵可显著提高黑枣酸奶的可滴定酸度（46.48%）、持水力（4.75%）、可溶性固形物含量（3.85%）和胞外多糖含量（12.63%）。此外,益生菌强化发酵可使黑枣酸奶中乳酸菌活菌数达到9.63 lg CFU/mL,且有效改善黑枣酸奶的质构特性,其硬度值、弹性、内聚性和回复性分别为151.24 g、1.04 mm、0.96 g·s和0.28。     

Manufacture of Fermented Lactic Beverages Containing Probiotic Cultures

ABSTRACT: Lactic beverages (LB) are products prepared with yogurt, whey, and other ingredients; they are popular among consumers in Brazil. LB containing probiotics were manufactured to study bacteria viability and to evaluate product characteristics during shelf life. Although counts decreased, 5.3 × 10⁶ CFU/mL of probiotics in average after 28 d were found. LB behaved as pseudoplastic fluids with thixotropy, and flow curves were best fitted by Oswald-de-Waele model. Apparent viscosity and pH decreased slightly with storage. LB showed phase separation increasing until 35% after 14 d, stabilizing after. Finally, microscopy observations showed a dispersion of protein particles. Filamentous and spherical structures corresponded to guar and starch that were added as stabilizers. No differences were noticed between products containing yogurt bacteria and those with probiotics.     

含发酵乳杆菌HY01牦牛酸奶工艺优化及主体风味成分动态解析

利用具有益生性能的发酵乳杆菌HY01生产牦牛酸奶,首先通过单因素试验、响应面试验优化益生菌发酵条件,观察贮藏期间产品的品质变化,并且利用电子鼻解析不同后熟时间牦牛酸奶的香气成分变化。结果表明：发酵乳杆菌HY01生产牦牛酸奶的优化工艺条件为接种量4%、40 ℃发酵6 h时感官评分89.72 分,益生菌数8.90×108 CFU/mL。在28 d贮藏期内牦牛酸奶益生菌数高于107 CFU/mL,酸度低于118 °T。贮藏0～14 d时4 项质构指标（黏性、硬度、稠度、黏聚性）、双乙酰和乙醛含量、感官评分基本保持不变,14 d后下降。此外,电子鼻传感器对香气响应值的主成分分析表明,牦牛酸奶特征香气由氮氧化物、甲基类、硫化物和醇类组成,与市售鲜牛乳制备酸奶的香气含量区别显著。可见,含发酵乳杆菌HY01的牦牛酸奶不仅具有良好的性能及风味,而且有望对肠道健康起到有益作用。     

添加小球藻和几种低聚糖对益生菌增殖和酸奶品质的影响

研究低聚果糖、水苏糖以及它们和蔗糖的组合对酸奶益生菌增殖的影响,并研究酸奶中添加小球藻粉对酸奶益生菌增殖及酸奶品质改进的影响。选用酵母菌发酵法对小球藻进行脱腥,果胶为稳定剂,发现酸奶制品中单一添加水苏糖和低聚果糖或两者组合都能促进益生菌的生长,而添加小球藻粉对于菌的生长及酸奶的营养和风味较有益。再通过L9(34)正交试验优化小球藻酸奶配方,最后确定较优配方为：10%脱脂奶粉、3%保加利亚乳杆菌和嗜热链球菌(质量比1:1)、5%蔗糖、3%低聚果糖、1%水苏糖及1%小球藻粉。     

Effect of 2 types of resistant starches on the quality of yogurt

This study investigated the effects of resistant starch (RS) 2 (a high-amylose corn starch) and RS3 (physically modified corn starch) on yogurt quality. Yogurt containing Bifidobacterium BB-12 was treated with RS2 or RS3 to a final concentration of 1.5%, with the control group receiving 1.5% (wt/wt) of sucrose. Multispeckle diffusing wave spectroscopy and scanning electron microscopy were used to investigate the effect of the resistant starches on the gelation process and microstructure of yogurt. The quality of the yogurt treatments was evaluated using viable counts of Bifidobacterium BB-12 and all viable cells, titratable acidity, amount of whey separation, and viscosity during storage. The resistant starches affected the progress of gelation and microstructure and decreased the decline of viable counts of Lactobacillus. Notably, RS3 effectively protected the Bifidobacterium BB-12, increased the viscosity, and decreased titratable acidity. Our results suggested that RS could improve the quality of yogurt and have a more probiotic effect. Further studies could lead to optimization in yogurt processing by mixing these 2 types of RS to determine their best usage and explore their interactions with proteins.     

Effect of refrigerated storage time on the viability of probiotic bacteria in fermented probiotic milk drinks

The viability of Lactobacillus acidophilus and Bifidobacterium lactis in fermented milks A, B and AB, containing respectively these strains separately and mixed, was studied over 21 days of storage at 5°C. Samples were analysed for titratable acidity and viable cell counts of probiotics. Milks A and AB showed post-acidification mainly due to the β-galactosidase activity of L. acidophilus . Generally, the viability of the probiotics decreased during storage, whereas, in some cases, the proteoletic activity of L. acidophilus resulted in a higher survival rate of the probiotics even with the adverse effects of low temperature and organic acids.     

富含γ-氨基丁酸藜麦发酵饮料工艺优化

以藜麦为原料,用短乳杆菌CGMCC 1.214和乳酸乳球菌CGMCC 1.62进行混合发酵,得到一种富含益生菌和γ-氨基丁酸(γ-aminobutyric acid,GABA)的藜麦非乳益生菌发酵饮料。在单因素实验基础上,采用响应面法考察接菌量、发酵温度与发酵时间对饮料中GABA含量和活菌数的影响。结果表明,在短乳杆菌:乳酸乳球菌=1:1的情况下,接菌量3.6%、发酵温度为31.0 ℃、发酵时间为22 h,测得发酵液中GABA含量为(0.681±0.003) mg/mL,活菌数为(9.176±0.001)lg (CFU/mL),与模型预测相对误差≤1%,与模型预测值吻合。藜麦益生菌饮料在保存藜麦营养物质的同时增加益生菌保健作用,为藜麦功能性食品研究提供新的理论依据。