低聚异麦芽糖改善小鼠胃肠道功能的研究

以二月龄雄性BALB／c小鼠为实验对象,研究了IMO－50与IMO－90调节胃肠道菌群的功能,结果表明：连续给予IMO－50或IMO－9014天后,小鼠胃肠疲乏内双歧杆菌数量显著增加。以二月龄雄性BALB／c小鼠为实验对象,以复方地芬诺酯建立的便秘模型为参比对照,研究IMO-50IMO－90的润畅通便功能,结果表明：在连续给予受试物14天后,便秘小鼠的肠推进率显著提高,首便、首黑便时间明显缩短,8小时排便重量显著增加。提示IMO－50和IMO－90均可改善小鼠胃肠道功能。     

Bifidobacterium carbohydrases-their role in breakdown and synthesis of (potential) prebiotics

There is an increasing interest to positively influence the human intestinal microbiota through the diet by the use of prebiotics and/or probiotics. It is anticipated that this will balance the microbial composition in the gastrointestinal tract in favor of health promoting genera such as Bifidobacterium and Lactobacillus. Carbohydrates like non-digestible oligosaccharides are potential prebiotics. To understand how these bacteria can grow on these carbon sources, knowledge of the carbohydrate-modifying enzymes is needed. Little is known about the carbohydrate-modifying enzymes of bifidobacteria. The genome sequence of Bifidobacterium adolescentis and Bifidobacterium longum biotype longum has been completed and it was observed that for B. longum biotype longum more than 8% of the annotated genes were involved in carbohydrate metabolism. In addition more sequence data of individual carbohydrases from other Bifidobacterium spp. became available. Besides the degradation of (potential) prebiotics by bifidobacterial glycoside hydrolases, we will focus in this review on the possibilities to produce new classes of non-digestible oligosaccharides by showing the presence and (transglycosylation) activity of the most important carbohydrate modifying enzymes in bifidobacteria. Approaches to use and improve carbohydrate-modifying enzymes in prebiotic design will be discussed.     

冻干酸奶粉的速溶性及发酵性研究

本文采用冻干法生产酸奶粉,对其速溶性和发酵性等进行了研究,结果发现:冻干酸奶粉具有良好的速溶性,其静置时的润湿下沉时间为76s,最适冲调条件为4～5倍45℃的温水。冻干酸奶粉的活菌数和菌活力分别为7.53×10~8cfu/g和85℉,将冻干酸奶粉作为发酵剂生产酸奶时,3.5hr即凝固且所得酸奶品质良好。     

羧甲基淀粉作酸奶稳定剂的应用效果研究

对羧甲基淀粉作为酸奶稳定刺及其应用效果进行了分析研究。结果表明：蔗糖添加8％，发酵温度为42℃，菌种比例为St：Lb=1．5：1的前提下，通过正交试验筛选出最佳发酵工艺条件为CMS添加0．1％、发酵时问为4h、接种量为3％．在4℃的保存条件下，添加CMS的酸奶比对照组酸奶的保质期至少延长了2d。     

Microencapsulation of Lactobacillus rhamnosus GG by Transglutaminase Cross‐Linked Soy Protein Isolate to Improve Survival in Simulated Gastrointestinal Conditions and Yoghurt

Microencapsulation is an effective way to improve the survival of probiotics in simulated gastrointestinal (GI) conditions and yoghurt. In this study, microencapsulation of Lactobacillus rhamnosus GG (LGG) was prepared by first cross‐linking of soy protein isolate (SPI) using transglutaminase (TGase), followed by embedding the bacteria in cross‐linked SPI, and then freeze‐drying. The survival of microencapsulated LGG was evaluated in simulated GI conditions and yoghurt. The results showed that a high microencapsulation yield of 67.4% was obtained. The diameter of the microencapsulated LGG was in the range of 52.83 to 275.16 μm. Water activity did not differ between free and microencapsulated LGG after freeze‐drying. The survival of microencapsulated LGG under simulated gastric juice (pH 2.5 and 3.6), intestinal juice (0.3% and 2% bile salt) and storage at 4 °C were significantly higher than that of free cells. The survival of LGG in TGase cross‐linked SPI microcapsules was also improved to 14.5 ± 0.5% during storage in yoghurt. The microencapsulation of probiotics by TGase‐treated SPI can be a suitable alternative to polysaccharide gelation technologies.     

枸杞保健型发酵酸乳的研制

以牛乳和枸杞为主要原料进行枸杞保健型发酵酸乳的研制，通过研究确定了枸杞的最佳添加量及最佳发酵时间，通过L9（3^4）因素3水平正交实验和对产品综合评分，确定了产品最佳配方为枸杞的添加量0.2%、接种量3%、白砂糖6%、果胶添加量0.1%。     

低脂无糖保健酸奶的研制

在酸奶配方的基础上,利用低聚果糖和木糖醇配比以取代全部的蔗糖,利用脱脂乳粉部分取代全脂乳粉,采用多因素正交试验设计出低脂无糖保健酸奶的最佳配方。结果表明：采用低聚果糖和木糖醇配比为1.5%和4.0%,脱脂乳粉和全脂乳粉配比为4.5%和4.0%,低脂无糖保健酸奶的感官品质最佳。     

双歧杆菌酸奶冻干发酵剂不同菌株特性的研究

研究了不同来源的4株双歧杆菌在乳中的生长与发酵特性、冷藏期间的存活力和后酸化活性以及抗冷冻干燥特性。结果表明:4菌株在乳中42℃发酵的凝乳时间均为6.0h,Blm和Bbm凝乳后的活菌数高,均在1×109cfu/mL以上,而其pH值均在5.0左右,滴定酸度70～80°T,且无显著差别;4菌株在发酵后的酸乳中冷藏期间,Blm和Bbm的存活力高,Blm、Bbm和Blr均表现出较低的后酸化活性;4℃冷藏21d,Blm和Bbm活菌数下降至不足1个log数量级,Blm、Bbm和Blr的酸度上浮不足10°T,pH值下降仅0.2～0.3;4菌株在以脱脂乳为保护剂的冷冻干燥试验中,Blm和Bbm抗冻干性强,其冻干存活率均在30%以上。     

Preservation of functionality of Bifidobacterium animalis subsp. lactis INL1 after incorporation of freeze-dried cells into different food matrices

The aim of this work was to investigate how production and freeze-drying conditions of Bifidobacterium animalis subsp. lactis INL1, a probiotic strain isolated from breast milk, affected its survival and resistance to simulated gastric digestion during storage in food matrices. The determination of the resistance of bifidobacteria to simulated gastric digestion was useful for unveiling differences in cell sensitivity to varying conditions during biomass production, freeze-drying and incorporation of the strain into food products. These findings show that bifidobacteria can become sensitive to technological variables (biomass production, freeze-drying and the food matrix) without this fact being evidenced by plate counts.     

酸乳制品中乳酸菌分离筛选方法研究

将保加利亚乳酸杆菌和嗜热链球菌在七种固体培养基中的生长情况进行比较，结果表明，酸化ＭＲＳ和Ｍ１７培养基分别是该两菌的较好的分离培养基。菌种的筛选应进行产酸风味和组织状态的综合比较，两菌不同组合菌株的选择应结合不同发酵条件进行。通过该方法分离筛选到不同风味类型的两组混菌。