水苏糖对酸乳增菌效果的研究

以保加利亚乳杆菌、嗜热链球菌、嗜酸乳杆菌和双歧杆菌为发酵菌种,进行了水苏糖对酸乳增茼效果的研究.在Lb及St(菌种比例1:1)的组合中,水苏糖添加量为0.8%时发酵时间缩短为4h(对照4.5h),菌教最高可达6.26 ×108cfu/mL(对照5.74 × 108cfu/mL).在Lh、St及La(菌种比例1:1:1)的组合中,水苏糖添加量为0.7%～0.8%时发酵时间缩短为5h(对照5.5h),菌数最高可达5.51 ×108cfu/mL(对照5.28×108cfu/mL).在Lb、St及BB(菌种比例1:1:2)的组合中,水苏糖添加量为0.8%时发酵时间缩短为4h(对照4.5h),菌教最高可达6.82×108cfu/mL(对照5.86×108cfu/mL).在Lb、St、La及BB(菌种比例1:1:1:2)的组合中,水苏糖添加量为0.8%时菌数最高可达6.29 × 108cfu/mL(对照5.45×106cfu/mL).     

复合北虫草乳酸菌制剂制备技术研究初探

探索了利用北虫草提取物培养乳酸菌,以期提高发酵液活菌数,进行了单菌种和双菌种混合发酵研究,并试制了具有北虫草和乳酸菌双重功能的复合北虫草活性乳酸菌制剂样品。研究结果表明,北虫草提取物对试验菌株生长具有促进作用,提高发酵液活菌数约10倍,实验室条件下单菌种和多菌种混合发酵液活菌数可达到109cfu/mL以上;制备的北虫草活性菌原粉活菌数最高达1011cfu/g、活性乳酸菌片和活性乳酸菌粉产品活菌数达107～109cfu/g。该产品将具有良好保健功能的北虫草和乳酸菌等益生菌相结合,为进一步研究开发复合型保健食品提供依据和思路。     

微胶囊技术在益生菌CICC 6075冰淇淋中的应用

为探究微胶囊技术在冰淇淋生产中的可行性,本研究以乳蛋白为壁材,应用乳化法制备嗜酸乳杆菌CICC 6075微胶囊。以未加菌的冰淇淋(冰淇淋A组)为空白对照,探讨了微胶囊(冰淇淋C组)及裸菌(冰淇淋B组)的添加对冰淇淋理化性质、感官性状等指标的影响。结果表明,添加CICC 6075裸菌及微胶囊均未对冰淇淋的性质产生明显影响。但在冰淇淋的加工及贮藏过程中,微胶囊由于致密的结构可对菌体提供良好的保护,因而明显提高了CICC 6075的活菌数。搅拌凝冻使冰淇淋B中的CICC 6075活菌数下降(1.20±0.08)lg CFU/g,而冰淇淋C中仅下降(0.09±0.07)lg CFU/g;在-18 ℃的条件下贮藏150 d,冰淇淋B中的活菌数降至(5.54±0.03)lg CFU/g,低于益生菌发挥健康功效的最低阈值;而冰淇淋C中仅下降了(0.60±0.08)lg CFU/g,最终活菌数高达(8.09±0.03)lg CFU/g。此外,在消化特性检验中发现,150 d的低温贮藏,使冰淇淋B中CICC 6075的耐胃酸性和对小肠上皮细胞的粘附性均明显下降(6.16%±0.04%,16.76%±0.05%),明显高于冰淇淋C的下降率(1.92%±0.07%,4.47%±0.09%)。综上,微胶囊技术可以明显提升益生菌对不良环境(如低温、胃液)的抗性,因而可以在保证冰淇淋良好品质特性的同时,提升其功能活性,具有一定的应用前景。     

益生菌在婴幼儿配方奶粉中稳定性的研究

探讨了向婴儿配方粉中添加4种益生菌,采用加速实验,研究益生菌在婴儿配方粉储存期间的稳定性。以益生菌的活菌量为检测指标,通过加速实验,确定最佳的加速实验温度为37℃。采用37℃为配方粉的储存条件,研究婴儿配方粉储存过程中益生菌的稳定性。结果证明:菌种A稳定性最好,在加速实验5个月后,活菌量只降到添加时活菌量的1/2。其次为菌种B和D,菌种C稳定性较差,不适宜添加到婴幼儿配方粉中。     

益生菌冰淇淋的研制

研究益生菌冰淇淋的配方及生产工艺.结果表明:改良后的增菌培养基可以获得3×10(9) cfu/mL的双歧杆菌活菌数,在6500g/5 min的离心作用下,可使活菌收得率达到96.6%;益生菌冰淇淋混合料中乳酸菌活菌数和双歧杆菌数在老化过程中上升到原来的1.1倍～1.2倍,保护剂加入与否差异不显著,但是在凝冻和-20℃贮藏30 d后,空白样、加葡萄糖和加乳糖样乳酸菌总数分别下降到凝冻前的53.2%、79.1%和69.9%,双歧杆菌下降到凝冻前的48.8%,80.0%和67.5%.结果表明加入5.0%的葡萄糖作为乳酸菌保护荆可有效减缓活菌数在凝冻和贮藏过程中的降低,并且最终活菌总数可达到1.2×10(8) cfu/mL;根据口感和活菌数量的综合评定,最终确定冰淇淋配方控制和工艺条件为:酸奶加入量最佳比例40%;老化最佳条件2℃～3℃,8 h;脂肪含量8%;复合乳化稳定剂含量0.6%;冷冻保护剂用葡萄糖(5%).     

发酵大豆乳优良乳酸菌菌种的筛选及其发酵性能的研究

本文以从益生菌乳制品、保健品和微生态制剂中自行分离选育出的乳酸菌进行大豆乳发酵,通过是否凝乳、凝乳时间长短、凝乳后的感官评价及发酵剂所达到的活菌数、酸度和pH值等技术指标,对适合大豆乳发酵的乳酸菌菌种进行层层选优得到生长繁殖力强、发酵活力高的大豆乳发酵的试验菌株.试验结果表明:8株实验乳酸菌菌株经过筛选得到干酪乳杆菌05-20作为发酵的大豆酸乳的备选菌株,其凝乳时活菌数可达1. 7× 109 cfu/mL、凝乳时pH值4. 29、滴定酸度79. 4°T,为开发混种发酵大豆乳和大豆功能性食品的开发奠定实践基础.     

发酵核桃乳优良益生菌的筛选及蛋白酶活力的测定

以分离自健康人体、酸泡菜、保健品等的13株第2代新型益生菌为试验菌株,研究了13株菌在纯核桃乳中的生长活力、产酸特性及感官性能,筛选出了适宜发酵核桃乳的益生菌,并分析了筛选出的菌株发酵核桃乳的蛋白酶活力。结果表明:13株第2代新型益生菌中干酪乳杆菌05-20和植物乳杆菌07-191在纯核桃乳中37℃发酵12 h后,活菌数分别为7.83×10~8、8.20×10~8 cfu/m L,p H值分别为5.05、5.06,产酸能力强、繁殖活力高、感官风味和组织状态俱佳;其他11株菌的活菌数均低于6.40×10~8 cfu/m L;2株菌在纯核桃乳中37℃培养12 h后蛋白酶活力分别为0.838、1.064 U/m L。研究结果为进一步研发益生菌发酵核桃乳产品奠定了基础,也为其他植物蛋白的精深加工提供了思路和方法。     

保加利亚乳杆菌冻干菌种的研究

对酸奶发酵菌种之一--保加利亚乳杆菌的增菌培养基进行了筛选,得到了高活菌数的保加利亚乳杆菌增菌培养基,并进行冷冻升华干燥得到保加利亚乳杆菌的冻干菌种。结果表明:在添加有10%麦芽汁、10%番茄汁、0.05%CaCO3、1.0%乳糖的MRS基础培养基中培养保加利亚乳杆菌18h后活菌数可达到3.96×1011cfu/g。其冻干菌种的活菌数为2.53×1011cfu/g。     

纳豆风味改良技术的研究

纳豆是一种健康食品,但其固有的风味不易被人们接受,实验研究了纳豆风味改良的方法。采取改变发酵过程的菌种、C/N、添加辅料等措施,以气味、口感、拉丝、色泽、黏液等感官品质为评价指标,研究其对纳豆风味的影响。得到最佳的改良方案:黄豆和白糖的比例为5∶1,100℃,蒸50min,发酵20h,与等量酸奶混合,后熟。产品的香气和滋味协调,纳豆所带氨味最少,含水量为61.02%,黏液率为5.72%,氨基酸态氮为19.18g/dL,大肠杆菌为8×102 cfu/mL,符合国家标准,纳豆激酶酶活为54.55U/g。     

益生性植物乳杆菌对切达干酪挥发性风味形成的影响

将分离自西藏灵菇的益生性植物乳杆菌1-2通过在杀菌乳中添加活菌数8.0、9.0（lg（CFU/mL））和在排乳清后添加于凝乳块8.0（lg（CFU/g））的方式分别加入到切达干酪中,考察植物乳杆菌活菌数量、添加方式和成熟时间对干酪挥发性风味物质组成的影响。利用固相微萃取和气相色谱-质谱联用技术检测出对照组干酪的风味物质26种,益生菌干酪组风味物质30种,添加植物乳杆菌1-2可产生乙苯、十二烷、己醇和丙酮4种挥发性风味物质。成熟时间对干酪风味的影响最大,随成熟时间的延长,益生菌干酪组中苯含量显著增加,而对照组干酪在成熟12周时才检测到苯。益生菌添加量和添加方式对干酪挥发性风味的影响相似,丁酸受益生菌活菌数和添加方式的影响最大,益生菌干酪组成熟12周时,丁酸含量最高达对照组的3.96倍（P＜0.05）。在杀菌乳中添加益生菌活菌数8.0（lg（CFU/mL））组和9.0（lg（CFU/mL））组干酪中挥发性风味物质含量有显著差异,但在杀菌乳中添加高活菌数9.0（lg（CFU/mL））和在排乳清后添加低活菌数8.0（lg（CFU/g））于凝乳块中对干酪挥发性风味的形成具有相似的影响。本研究结果为改进益生菌干酪的加工工艺和风味品质提供了实验依据。     

Bacterial survival and adhesion for formulating new oral probiotic foods

Abstract

Probiotics are defined as live microorganisms, which, when administered in adequate amounts, confer health benefits to the host. Traditionally, probiotic food research has heavily focused on the genera Bifidobacteria and Lactobacilli, along with their benefits for gut health. Recently with the identification of new probiotic strains specifically intended for oral health applications, the development of probiotic foods for oral health benefits has garnered interest, with a renewed focus on identifying new food formats for delivering probiotics. The development of novel oral probiotic foods is highly complex, as the composition of a food matrix dictates: (1) bacterial viability during production and shelf life and (2) how bacteria partition with components within a food matrix and subsequently adhere to oral cavity surfaces. At present, virtually no information is available on oral probiotic strains such as Streptococcus salivarius; specifically, how orally-derived strains survive under different food parameters. Furthermore, limited information exists on the partition behavior of probiotics with food components, governed by physico-chemical interactions and adhesion phenomena. This review aspires to examine this framework by providing a foundation with existing literature related to the common probiotic genera, in order to inform and drive future attempts of designing new oral probiotic food formats.     

Selection and design of probiotics.

Over the past 5 years the probiotic field has exploded with a number of new cultures, each purported to elicit a variety of benefits. Lists of functional characteristics and benefits, in vivo, are now commonplace to any presentation on probiotics. Scientifically established health claims remain among the highest priorities to companies who seek to establish solid health benefits that will promote their particular probiotic. The scientific community faces a greater challenge and must objectively seek cause and effect relationships for many potential and currently investigated probiotic species and strain combinations. Rational selection and design of probiotics remains an important challenge and will require a platform of basic information about the physiology and genetics of candidate strains relevant to their intestinal roles, functional activities, and interactions with other resident microflora. In this context, genetic characterization of probiotic cultures is essential to unequivocally define their contributions to the intestinal microbiota and ultimately identify the genotypes that control any unique and beneficial properties. Strain selection and differentiation, based on the genetic complement and programming of a candidate probiotic, then becomes feasible. Looking ahead, it will be vital to the development of this exploding field to correlate important characteristics in probiotics with known genotypes and regulatory controls that are likely to affect functionality and beneficial outcomes, in vivo.     

The effects of probiotics in lactose intolerance: A systematic review

Over 60 percent of the human population has a reduced ability to digest lactose due to low levels of lactase enzyme activity. Probiotics are live bacteria or yeast that supplements the gastrointestinal flora. Studies have shown that probiotics exhibit various health beneficial properties such as improvement of intestinal health, enhancement of the immune responses, and reduction of serum cholesterol. Accumulating evidence has shown that probiotic bacteria in fermented and unfermented milk products can be used to alleviate the clinical symptoms of lactose intolerance (LI). In this systematic review, the effectiveness of probiotics in the treatment of LI was evaluated using 15 randomized double-blind studies. Eight probiotic strains with the greatest number of proven benefits were studied. Results showed varying degrees of efficacy but an overall positive relationship between probiotics and lactose intolerance.     

益生菌的科学共识(2020年版)

目的:2020年中国食品科学技术学会益生菌分会根据益生菌的最新研究进展,形成《益生菌的科学共识(2020年版)》。方法:组织科技界与产业界的相关专家以专题研讨会的形式,发言、交流、记录并撰写成文。结果:益生菌的安全性已得到国内外权威机构的认可,其标准法规体系的完善需要扎实的科学基础为支撑,其3个核心特征为足够数量、活菌状态和有益健康功能。人类对益生菌功效的探索和评价是一个长期、严谨、科学的过程,需要加强公众科普教育,科学合理消费益生菌相关产品。结论:该共识将对我国益生菌行业的发展和创新具有重要的指导意义。     

Probiotic bacteria: selective enumeration and survival in dairy foods

A number of health benefits have been claimed for probiotic bacteria such as Lactobacillus acidophilus, Bifidobacterium spp., and Lactobacillus casei. Because of the potential health benefits, these organisms are increasingly incorporated into dairy foods. However, studies have shown low viability of probiotics in market preparations. In order to assess viability of probiotic bacteria, it is important to have a working method for selective enumeration of these probiotic bacteria. Viability of probiotic bacteria is important in order to provide health benefits. Viability of probiotic bacteria can be improved by appropriate selection of acid and bile resistant strains, use of oxygen impermeable containers, two-step fermentation, micro-encapsulation, stress adaptation, incorporation of micronutrients such as peptides and amino acids and by sonication of yogurt bacteria. This review will cover selective enumeration and survival of probiotic bacteria in dairy foods.     

婴幼儿用益生菌的研究现状及面临的挑战

益生菌是活的微生物,当摄入足够数量时,对宿主起有益健康的作用。研究发现母乳中含有活的微生物,使婴幼儿用益生菌被广泛关注。目前,国际上没有对"婴幼儿用益生菌"明确统一的定义及共识。通过阐述婴幼儿用益生菌的种类、常用菌株、安全性、临床研究的现状,指出研究最多的是乳酸杆菌属(Lactobacillus)和双歧杆菌属(Bifidobacterium),诸多报道显示其安全性良好,但是大多益生作用研究来自动物实验,成熟的、具有明确保健功能的益生菌菌株较少,尤其缺乏充分的临床研究。婴幼儿益生菌在研究和产业方面面临3方面挑战:现代肠道优势菌群新发现与传统益生菌菌株的矛盾,健康功能及作用缺乏像药物一样更深层面的精准机制解析,以及婴幼儿益生菌的法规与新菌株临床试验研究的矛盾。尽管面临诸多问题,但是,针对婴幼儿,特别是中国婴幼儿,特有的胃肠功能、免疫系统等尚未发育健全,这一独特的生理特点,开发婴幼儿用益生菌将具有重要前景。     

Probiotics down-regulate flaA sigma28 promoter in Campylobacter jejuni

Lactobacilli and bifidobacteria are important members of the gastrointestinal microflora of humans and animals and are thought to have positive effects on human health. Therefore, there is an increasing interest in using these microorganisms as probiotics to be incorporated into either fermented dairy products or tablets. However, convincing scientific data that support claims of their health benefits are scarce. The effect of cell-free extracts of milk fermented by 10 probiotic bacteria (five Bifidobacterium strains and five Lactobacillus strains) on the expression of the flaA gene of Campylobacter jejuni was assessed using a fusion between the flaA sigma28 promoter and a promoterless luxCDABE cassette carried on the plasmid pRYluxCDABE, which resulted in strains with quantifiable luminescence linked to flaA sigma28 promoter activity. Cell-free extracts of milk fermented by all of the tested probiotic strains inhibited the growth of the C. jejuni and down-regulatedflaA sigma28 promoter activity. Two nonprobiotic lactic acid bacterial strains, Lactococcus lactis and Streptococcus thermophilus, were less inhibitory.     

The Effect of Digestive Enzymes on the Adhesion of Probiotic Bacteria In Vitro

ABSTRACT: Specific probiotics have several clinically proven health effects. Adhesion to the intestinal mucosa is considered important for many of these effects. In the current study, the effect of digestive enzymes and bile on the adhesion to intestinal mucus of 5 selected probiotics was studied. All of the digestive enzymes affected the adhesion of at least some of the tested strains. Bile was observed to reduce the adhesion of all strains tested. When the strains were sequentially exposed to 3 enzyme preparations and bile, the level of adhesion was reduced for all strains. The results suggest that the selection criterion "adhesion" for probiotics should be further refined.     

基于聚合物载体的益生菌递送系统：载体类型、性能评价及新技术应用

益生菌赋予宿主多种健康益处,并可用于防治胃肠道和非胃肠道疾病,例如腹泻、结肠癌、肥胖症、神经系统疾病、糖尿病和炎症等。然而益生菌在生产加工,储存和消化过程中受各种环境因子作用进而影响其活菌存活率。如何最大限度的保持益生菌的活力和稳定性成为当前益生菌的研究热点之一。具有生物相容性和可降解性的聚合物可作为益生菌的给药载体,能有效增强益生菌活性、延长储存时间、减少益生菌在胃部的损失,甚至实现结肠和粘膜的靶向递送。该研究综述了当前封装益生菌聚合物载体的类型以及益生菌递送系统的评价方式,并探讨了制备益生菌递送系统的新技术。结果表明有机结合递送系统新技术和多样化评估手段,建立具有稳定性、功能性、安全性、有效性以及靶向能力的益生菌递送系统,可实现对益生菌的高效递送,将进一步促进多功能益生菌在食品或药物领域的应用。     

Implications of Antibiotic Resistance in Probiotics

Collectively, many lactobacilli form a major group of health-promoting microorganisms. A subset of which are generally known as probiotics. Emergence of antibiotic-resistant strains is challenging human health and well-being, particularly antibiotic therapy for the treatment of bacterial infections. Lactobacilli may prevent gastrointestinal disruption during antibiotic therapy by helping to reestablish or maintain the normal microbiota of the intestine. To achieve this, lactobacilli must survive in the presence of coadministered antibiotics. Hence, antibiotic resistance of probiotics is an essential criterion for their screening and selection, provided of course that they do not pose a threat by way of the transfer of antibiotic resistance genes to other bacteria. This article addresses the types of antibiotic resistance and transfer mechanisms, the antibiotic resistance profile of probiotic lactobacilli, as well as the benefits associated and concerns raised with antibiotic resistance of probiotic bacteria.