Modulation of Intestinal Epithelial Defense Responses by Probiotic Bacteria

Probiotics are live microorganisms, which when administered in food confer numerous health benefits. In previous studies about beneficial effects of probiotic bacteria to health, particularly in the fields of intestinal mucosa defense responses, specific probiotics, in a strain-dependent manner, show certain degree of potential to reinforce the integrity of intestinal epithelium and/or regulate some immune components. The mechanism of probiotic action is an area of interest. Among all possible routes of modulation by probiotics of intestinal epithelial cell-mediated defense responses, modulations of intestinal barrier function, innate, and adaptive mucosal immune responses, as well as signaling pathways are considered to play important role in the intestinal defense responses against pathogenic bacteria. This review summarizes the beneficial effects of probiotic bacteria to intestinal health together with the mechanisms affected by probiotic bacteria: barrier function, innate, and adaptive defense responses such as secretion of mucins, defensins, trefoil factors, immunoglobulin A (IgA), Toll-like receptors (TLRs), cytokines, gut associated lymphoid tissues, and signaling pathways.     

Survival and Activity of Probiotic Lactobacilli in Skim Milk Containing Prebiotics

ABSTRACT: Seven strains were cultured anaerobically at 37 °C for 48 h in 12% (w/v) reconstituted skim milk containing 5% (w/v) Hi-maize, lactulose, inulin, or raftilose. Their viability was determined before and after 4 wk of storage at 4 °C. Doubling time (Td) was also determined. Concentrations of acetic and lactic acids produced during fermentation and storage were determined. The Td ranged from 301 to 751 min. In general, the viability of lactobacilli after storage was greatest with inulin. The pH after storage in skim milk ranged from 4.34 (for ASCC 1520 with raftilose) to 4.10 (for ATCC 15820 with inulin). Survival of lactobacilli in prebiotic was strainspecific but in general their survival was enhanced.     

新剂型香精及其包埋技术的应用

新剂型香精区别于传统液体香精的地方在于采用了包埋技术,将各种保护性壁材以不同方式和过程包覆香精,从而保护香精,赋予香精更优越的性能。文中介绍了五种新剂型香精:分子胶囊香精、纳米胶囊香精、微胶囊香精、颗粒香精、爆珠香精,并阐述了其制备方法及优缺点。     

提高食品中益生菌数量的两大新技术

益生菌是一种对人类健康起着重要作用的微生物,并广泛应用于食品生产,然而,益生菌自身比较脆弱,容易受周围环境的影响而导致食品中益生菌菌数的快速下降,严重影响了益生菌的益生作用,因此,对益生菌进行包埋,提高食品中益生菌的稳定性和存活能力将对我们进一步开发益生菌系列产品至关重要.本文根据目前国内外益生菌包埋技术研究的现状,对目前研究较多的微胶囊包埋技术和双层包埋技术的原理,优缺点以及实际应用情况进行综述。     

Optimization of Incorporated Prebiotics as Coating Materials for Probiotic Microencapsulation

ABSTRACT: The purpose of this research was to improve probiotic microencapsulation using prebiotics and modern optimization techniques to determine optimal processing conditions, performance, and survival rates. Prebiotics (fructooligosaccharides or isomaltooligosaccharides), growth promoter (peptide), and sodium algi-nate were incorporated as coating materials to microencapsulate 4 probiotics ( Lactobacillus acidophilus, Lacto-bacillus casei, Bifidobacterium bifidum , and Bifidobacterium longum ). The proportion of the prebiotics, peptide, and sodium alginate was optimized using response surface methodology (RSM) to 1st construct a surface model, with sequential quadratic programming (SQP) subsequently adopted to optimize the model and evaluate the survival of microencapsulated probiotics under simulated gastric fluid test. Optimization results indicated that 1% sodium alginate mixed with 1% peptide and 3% fructooligosaccharides as coating materials would produce the highest survival in terms of probiotic count. The verification experiment yielded a result close to the predicted values, with no significant difference ( P > 0.05). The storage results also demonstrated that addition of prebiotics in the walls of probiotic microcapsules provided improved protection for the active organisms. These probiotic counts remained at 10⁶ to 10⁷ colony-forming units (CFU)/g for microcapsules stored for 1 mo and then treated in simulated gastric fluid test and bile salt test.     

益生菌酸乳开发中的关键问题

根据益生菌生物特性并结合国内外发展及应用状况,讨论了益生菌菌株的选择,发酵剂设计,生产与保藏过程中品质的控制等产品开发中的关键问题.     

The Beneficial Use of Cereal and Cereal Components in Probiotic Foods

Cereals and cereal components can be used as fermentation substrates for probiotic organisms imparting prebiotic effects. Consumer interest in healthy functional foods has resulted in the need for food products with versatile health-benefiting properties. The conventional choice for probiotic food applications has been dairy-based products, but whole grain-based probiotic functional foods have debuted in Japan and Europe. In the US, pro- and prebiotics are mainly marketed as dietary supplements, but are moving towards inclusion in the diet as mainstream foods. Cereal constituents, such as wheat bran-based ingredients fermented with probiotics, would enhance consumer health with the benefits of probiotics, bran fiber, and healthful bioactive components.     

糖接枝玉米醇溶蛋白包埋虾青素

本研究利用葡萄糖和木糖两种还原糖对玉米醇溶蛋白（zein）进行糖接枝改性,并制备改性zein/虾青素复合 微粒,研究糖接枝改性对包埋虾青素的影响。zein-葡萄糖/木糖的接糖量分别为2.59%和2.53%,十二烷基硫酸钠-聚 丙烯酰胺凝胶电泳后的考马斯亮蓝染色和希夫试剂染色结果也充分证明了糖蛋白的产生。圆二色谱测定结果表明, 经过糖接枝改性后的zein二级结构中α-螺旋结构含量显著减少,而β-折叠和β-转角结构含量增加,说明蛋白质发生 了一定程度的展开。扫描电子显微镜和差示扫描量热结果表明,虾青素经过zein包埋后形成的复合微粒为空心塌 陷的微粒,虾青素均匀分布在球体中。糖接枝改性后的zein对虾青素包埋率提高了10%。在无水乙醇体系下溶解 12 h,未包埋的虾青素释放率达99.8%,zein/虾青素、zein-葡萄糖/虾青素、zein-木糖/虾青素复合微粒中虾青素释放 率分别为49.7%、31.7%、30.2%。经过糖接枝改性的复合微粒显著提高了虾青素的热稳定性,在热处理过程中,未 被包埋的虾青素破坏率达75.29%,而经过包埋的虾青素破坏率均在25%以下。     

Recent Trends and Applications of Encapsulating Materials for Probiotic Stability

The importance of probiotics and their live delivery in the gastrointestinal tract has gained much importance in the recent past. Many reports have indicated that there is poor viability of probiotic bacteria in dairy based products, both fermented and non-fermented, and also in the human gastro-intestinal system is questionable. In this case, microencapsulation is the most significant emerging and efficient technology that is being used for the preservation of probiotics against adverse environmental conditions. Apart from different techniques of microencapsulation, various types of encapsulating materials are also used for the process, namely, alginate, chitosan, carrageenan, gums (locust bean, gellan gum, xanthan gum, etc.), gelatin, whey protein, starch, and compression coating. Each one of the encapsulating materials has its own unique characteristics of capsule formation and provision of shape, appearance, and strength to microbeads. The type of encapsulating material also influences the viability of probiotics during storage, processing, and in the gastrointestinal tract. The effectiveness of any material depends not upon its capsule forming capability, strength, and enhancing viability but also on its cheapness, availability, and biocompatibility. So, added convenience and reduced packaging costs may also be used to offset the cost of encapsulating one or more ingredients. Encapsulated forms of ingredients provide a longer shelf life for the product.     

Encapsulation increases the in vitro bioaccessibility of probiotics in yoghurt

This study examined the encapsulation efficacy of probiotics in yoghurts, product physicochemical properties, the best timing to add encapsulated probiotics during yoghurt manufacturing (before or after fermentation) and their in vitro bioaccessibility. Three different yoghurt types were produced including plain and with encapsulated probiotics added before and after fermentation. A significant (P < 0.05) reduction in total probiotic count was observed in yoghurts containing encapsulated probiotics after 21 days of refrigerated storage. However, the total probiotic count increased during the in vitro colonic fermentation when yoghurts containing encapsulated probiotics were used, indicating increased bioaccessibility of probiotics in the colon.     

静电纺丝技术包埋天然酚类化合物研究进展

天然酚类化合物因其对人体健康具有众多益处,近年来在食品、营养学和医药等领域得到了广泛的关注。然而,酚类化合物较差的溶解性、稳定性和生物利用度等严重地限制了其应用。如何有效地保护和运载这些酚类化合物并保持其生物活性成为研究的热点问题。静电纺丝是一种易于操作且成本低廉的纳米级纤维制备技术,所制备的纳米纤维可作为纳米载体对生物活性物质进行包埋和控制释放,因此可作为包埋酚类化合物的一种有效方法。本文概述了静电纺丝技术的基本原理、类型、影响参数、常用的聚合物基质和优势,对静电纺丝技术包埋天然酚类化合物的相关研究进行了综述,最后展望了其在食品工业的应用前景,以期为静电纺丝技术在食品领域应用提供一定的理论指导。     

Encapsulation and stimulated release of enzymes using lecithin vesicles

Lecithin vesicles prepared by dehydration-rehydration (DR) were used to encapsulate enzymes (lysozyme and pepsin). The encapsulating efficiency was highest when the pH was close to the isoelectric point of each enzyme. Vesicles stored in suspension at 10°C for up to 21 days showed no release of enzymes. Acidic pH at 10°C and 25 mM Ca²⁺ at 10°C or 37°C produced pulse-like release of 17–35%, while acidic pH at 37°C produced pulse-like release followed by slow release up to 100%, and Tween 80 induced steady release from the beginning. The hydrolysis pattern of a protein by pepsin released from DR vesicles for 142 hr was similar to that obtained by the same total amount of fresh pepsin solution added stepwise, in proportion, indicating that the pepsin retains its activity throughout the period of encapsulation.
Vesicles prepared by processing of lecithin-enzyme solution by a homogenizer (Microfluidizer^TM) were also characterized and found effective.     

食品运载体系包埋叶黄素的研究进展

叶黄素属于类胡萝卜素,具有多种生物活性功能,可以避免视网膜色素上皮细胞受蓝光损伤、预防心脑血管疾病、抗肿瘤等;此外,叶黄素还是天然的食品着色剂和抗氧化剂。但是叶黄素存在水溶性和化学稳定性较差、生物利用率低等缺陷,这限制了其在食品领域中的应用。利用食品运载体系可以解决上述问题。本文分析了限制叶黄素应用的原因,对现有食品运载体系包埋叶黄素的研究现状进行综述,以期为叶黄素的进一步研究与应用提供参考。     

猪用生长激素(PST)脂质体包封率测定方法的比较

试验对测定包封率的两种方法即凝胶柱分离法和鱼精蛋白凝聚法进行了比较，测得PST脂质体的包封率分别为75．26％、84．58％，PST回收率分别为90．4％和98．22％。因此确定了鱼精蛋白法为试验产品包封率的测定方法。     

食品运载体系包埋叶黄素的研究进展

叶黄素属于类胡萝卜素,具有多种生物活性功能,可以避免视网膜色素上皮细胞受蓝光损伤、预防心脑血管疾病、抗肿瘤等;此外,叶黄素还是天然的食品着色剂和抗氧化剂。但是叶黄素存在水溶性和化学稳定性较差、生物利用率低等缺陷,这限制了其在食品领域中的应用。利用食品运载体系可以解决上述问题。本文分析了限制叶黄素应用的原因,对现有食品运载体系包埋叶黄素的研究现状进行综述,以期为叶黄素的进一步研究与应用提供参考。     

钙诱导乳清分离蛋白包埋体系对VB12 的稳态研究

使用乳清分离蛋白作为载体,用以对VB12 进行包埋和保护。结果表明,常温下热变性处理后的乳清分离蛋白和Ca2+ 形成的网状结构可对VB12 进行有效包埋。通过改变乳清分离蛋白质量分数(5%、8%)和Ca2+ 浓度(0.05、0.10、0.20mol/L),所得产品中VB12 的包埋率最高可达50%。乳清分离蛋白包埋体系的VB12 释放实验表明,在模拟胃液介质中,该体系通过推迟VB12 的释放而在一定程度上减弱了酸和胃蛋白酶对VB12 的影响;而在模拟肠液介质中,蛋白体系逐渐被胰消化酶降解,因此,VB12 在2h 后几乎释放完全。     

Probiotic administration effect on fecal mutagenicity and microflora in the goat's gut

The application of potentially beneficial microorganisms to increase host defense is a new trend to increase health benefits. In this paper the first specific host probiotics for goats from a mixture isolated from healthy animals (Lactobacillus reuteri DDL 19, Lactobacillus alimentarius DDL 48, Enterococcus faecium DDE 39 and Bifidobacterium bifidum DDBA) was assayed. The effect of probiotic oral administration on goats' weight, gut microbiota, as well as on the production of mutagen compounds and their indicator (putrescine), were evaluated. The probiotic supplement was able to modify microflora balance by reducing Enterobacteria like Salmonella/Shigella (1.09 and 1.21 log CFU/g feces, respectively) and increasing lactic acid bacteria and Bifidobacteria (1.67 and 2.34 log CFU/g feces, respectively). The probiotics administration was correlated with a ten time diminution of fecal putrescine (cancer and bacterial disease marker) and a decrease of 60% mutagen fecal concentration, indicating the protective effect of the treatment. Additionally, a significant increase in ruminant weight was observed after probiotic administration. These results are encouraging towards the use of probiotic mixtures as functional food for goats.     

酸奶中益生菌的选择性计数的研究

对多菌种保健酸奶中各微生物的选择性计数方法进行了研究。利用非选择性培养基MRS-1和组分成分较简单的MGLP、MGLP-1两种选择性培养基,在37℃或15℃,厌氧或微好氧条件下对三种多菌种保健酸奶中保加利亚乳杆菌、干酪乳杆菌、嗜酸乳杆菌、双歧杆菌进行了选择性计数,方法简便易行。该方法可用于市售的其他类型的多菌种保健酸奶中特征性微生物的测定。     

益生菌种的应用和市场趋势

本文对全球益生菌种的最新研究及市场趋势作一简要阐述,同时,也对丹尼斯克公司在益生菌种的此前沿领域应用研究进展作了介绍.     

姜黄素的乳化和包埋及其应用研究进展

姜黄素是从姜科、天南星科中的一些植物的根茎中提取的一种化学成分,是植物界很稀少的具有二酮的色素。姜黄素作为我国允许使用的一种天然着色剂,具有一系列生物药理活性,但是其理化稳定性差、生物利用度低,往往需很大用量才能达到作用剂量,将其乳化包埋后不仅可以解决其溶解性的问题,还可以提高其生物利用率,应用前景十分广阔。该文通过总结国内外大量文献,阐述姜黄素的基本性质及其乳状液的基本性质和乳化包埋的方法,同时介绍姜黄素的创新应用,并对其发展前景作出展望。