以葵花籽油为底物生物转化共轭亚油酸双歧杆菌的筛选

运用快速扫描法,筛选了10株可利用游离态亚油酸为底物高产共轭亚油酸的双歧杆菌菌株;然后以富含非游离态亚油酸的葵花籽油为底物,与初筛得到的高产菌株共培养后检测反应体系中共轭亚油酸的含量。结果表明,部分短双歧杆菌可将葵花籽油转化为共轭亚油酸,其中短双歧杆菌FFJND12M6的转化率最高,可达14.35%。     

实时荧光定量PCR法测定发酵乳中双歧杆菌

对实时荧光定量聚合酶链式反应(PCR)技术检测发酵乳中双歧杆菌的DNA提取方法、PCR扩增效率、标准曲线绘制进行探讨,通过比较分析碱式提取法、玻璃珠破碎法和酶解法3种提取方法对发酵乳中总DNA提取效率、4种不同参考菌株的PCR扩增效率以及单一菌株标准曲线与混合菌株标准曲线的计数结果,建立实时荧光定量PCR快速测定发酵乳制品中双歧杆菌数量方法。结果表明：酶解法提取发酵乳中总DNA效果最好,OD260/280比值基本接近1.80,且提取的质量浓度含量最高;不同菌株的PCR扩增效率不同,其中参考菌株1.2213的Ct值与其他3菌株的Ct值存在显著性差异;根据单一菌株绘制标准曲线与混合菌株绘制标准曲线计数结果无显著性差异,后者计数结果更客观、准确。采用酶解法获取样品中的菌体细胞,基于混合菌液绘制标准曲线,采用实时荧光定量PCR技术确定发酵乳中双歧杆菌种属数量,可快速、准确地测定发酵乳中双歧杆菌的数量。     

改性双歧杆菌胞外多糖体外免疫活性研究

对双歧杆菌胞外多糖进行乙酰化、羧甲基化、多羟基化、主链降解修饰,并测定修饰前后多糖对IL-2、IFNγ细胞因子的影响。试验表明,与对照组相比,除主链降解修饰外,其他3种改性产品均能显著提高IL-2、IFNγ细胞因子的浓度,表现出体外免疫活性。其中,羧甲基化和多羟基化改性多糖的体外免疫活性高于未改性多糖。     

双歧杆菌和乳酸菌β-半乳糖苷酶转糖基作用的研究进展

双歧杆菌和乳酸菌作为一般认为安全的微生物,是β-半乳糖苷酶（β-galactosidase,β-gal）的较好来源。部分双歧杆菌和乳酸菌菌株能够产生具有转糖基活力的β-gal,以乳糖为底物可合成具有益生作用的低聚半乳糖（galactooligosaccharides,GOS）,而GOS产物的产量和组成受到β-gal的来源以及反应条件的影响。因此,本文总结了能够产生具有转糖基活力的β-gal的双歧杆菌和乳酸菌菌株,比较了两类来源的β-gal的酶学性质,并重点阐述了这两类β-gal在GOS合成中的应用。     

Growth, Viability and Activity of Bifidobacterium spp. in Skim Milk Containing Prebiotics

Growth, activity and mean doubling time (T_d) of five Bifidobacterium species in the presence of four types of prebiotics, and concentrations of acetic and lactic acids were determinted during fermentation and after 4 weeks of refrigerated storage. The T_d was lowest for B. animalis with raftilose and inulin. Retention of viability of bifidobacteria was greatest with hi‐amylose corn starch (hi‐maize). The average pH of skim milk at the end of 4 wks storage averaged 4.34 (for B. animalis with raftilose) to 4.07 (for B. longum with inulin). The highest levels of acetic acid and lactic acid were produced by B. pseudolongum with lactulose and B. infantis with lactulose, respectively.     

Fermented Milks and Milk Products as Functional Foods—A Review

Fermented foods and beverages possess various nutritional and therapeutic properties. Lactic acid bacteria (LAB) play a major role in determining the positive health effects of fermented milks and related products. The L. acidophilus and Bifidobacteria spp are known for their use in probiotic dairy foods. Cultured products sold with any claim of health benefits should meet the criteria of suggested minimum number of more than 10⁶ cfu/g at the time of consumption. Yoghurt is redefined as a probiotic carrier food. Several food powders like yoghurt powder and curd (dahi) powder are manufactured taking into consideration the number of organisms surviving in the product after drying. Such foods, beverages and powders are highly acceptable to consumers because of their flavor and aroma and high nutritive value. Antitumor activity is associated with the cell wall of starter bacteria and so the activity remains even after drying. Other health benefits of fermented milks include prevention of gastrointestinal infections, reduction of serum cholesterol levels and antimutagenic activity. The fermented products are recommended for consumption by lactose intolerant individuals and patients suffering from atherosclerosis. The formulation of fermented dietetic preparations and special products is an expanding research area. The health benefits, the technology of production of fermented milks and the kinetics of lactic acid fermentation in dairy products are reviewed here.     

含活性益生菌的发酵型红薯果冻的研制

以乳酸菌红薯发酵液,双歧酸牛乳,海藻钠酸,蔗糖等为主要原料,经过科学的配方,酿制得含丰富膳食纤维、乳酸菌、双歧杆菌等活性益生菌的保健型果冻食品。     

Biotransformation of Isoflavones by Bifidobacteria in Fermented Soymilk Supplemented with D-Glucose and L-Cysteine

ABSTRACT: Soymilk prepared using soy-protein isolate supplemented with D-glucose and L-cysteine was fermented with 4 strains of Bifidobacterium. Enumeration of bifidobacteria and quantification of isoflavones using HPLC were performed at 0, 12, 24, 36, and 48 h of incubation. Supplementation did not significantly enhance ( p > 0.05) the growth of bifidobacteria between 0 and 12 h, but did after 12 h. The increase in concentration of isoflavone aglycones and equol was significantly lower ( p < 0.05) in supplemented soymilk after 24 h when compared to plain soymilk. Supplementation increased the concentration of aglycones by 0.796 mg/100 mL in soymilk fermented with B. animalis between 12 and 24 h, and the population by 1.27 log₁₀ CFU/mL ( p < 0.05).     

双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料的工艺研究

以从健康人体中选育出的发酵活力高、耐氧性和抗逆性强的优良发酵菌株长双歧杆菌(Blm)作为主要试验菌株,以乳酸菌保加利亚乳杆菌(L.b-DR)和嗜热链球菌(S.t-3)作为辅助菌株,研究了接种量及菌种配比、基质起始pH值、发酵温度、氧气等因素对双歧杆菌与乳酸菌混合发酵胡萝卜汁牛乳饮料时,对凝乳时间、活菌含量、pH值和产品感官风味的影响。利用正交试验优化并确定了Blm与乳酸菌混合发酵的最佳工艺条件,即在胡萝卜汁牛乳培养基(25%胡萝卜汁和5%蔗糖)中,总接种量3%(3×107cfu/mL),其菌种配比为Lb-DR∶St-3∶Blm=1∶1∶1,基质起始pH值7.0,发酵温度39℃,有氧条件发酵。产品凝乳时间在3.33 h,pH值为4.5左右,总活菌数可达1×109cfu/mL以上,橙黄色,组织状态致密细腻,无乳清析出。对该产品的工艺条件探究,为开发其它功能性益生菌乳制品提供了新的思路和方法。     

Fermentation Capabilities of Bifidobacteria Using Nondigestible Oligosaccharides, and Their Viability as Probiotics in Commercial Powder Infant Formula

The species Bifidobacterium bifidum, Bifidobacterium breve, Bifidobacterium longum biotype infantis (Spanish type culture collection), and Bifidobacterium longum (Morinaga nutritional foods) were evaluated in vitro in the presence of 4 commercial nondigestible oligosaccharides (NDO) (short‐chain fructooligosaccharides [SCFOS] [degree of polymerization, DP: 2–3], inulin [DP: 10–0], oligofructose [DP: 2–0] and 4′‐galactosyllactose [4′‐GOS] [DP: 3–]). Each species was incubated anaerobically in tryptone phytone yeast (TPY) broth for 7 d with NDO. Every 24 h, bifidobacteria growth was evaluated by means of broth turbidity as optical density at 600 nm. Moreover, another sample was collected for pH culture measurement. Results showed that inulin was the substrate with the least effect on the stimulation of bifidobacteria growth and pH decrease. On the last day of incubation, the substrate 4′‐GOS stimulated bacterial growth more strongly and produced a larger decrease in culture broth pH than the other substrates. On the other hand, B. bifidum and B. longum showed a greater growth with 4′‐GOS. In a 2nd study, these 2 bifidobacteria species were added to a powder follow‐on probiotic infant formula. The viability of the bifidobacteria during the formula's period of consumption was evaluated in 2 studies of 6 and 14 d. Both corresponded to the minimum and maximum time of consumption of the formula according to the manufacturer's directions. It was found that, although in both studies bifidobacteria counts decreased significantly (P < 0.05) with time, they were always above the recommended addition level (10⁶ colony‐forming units [CFU]/g) at the time of sale for dairy products by the Intl. Standard of Fédération Internationale de Laiterie/International Dairy Federation (FIL/IDF). Moreover, because the pH of the reconstituted formula was always close to neutrality (from 6.74 to 7.06), the number of bacteria did not drop below the recommended level.