一株降胆固醇乳酸菌的鉴定及其在模拟胃肠环境中抗性的研究

鉴定一株有降胆固醇功能的益生菌LQ-12为乳酸乳球菌乳亚种。同时对该菌在模拟胃肠环境条件下的抗性及对肠道中致病性大肠杆菌、金黄色葡萄球菌的拮抗性和服用抗生素后的耐药性进行了研究。结果表明，LQ-12在pH1．5～4．5生活4h活菌数仍达10^6cfu／ml以卜，在0．1％～0．3％胆汁盐条件下4h活菌数仍达10^6cfu／ml以上。同时对致病性大肠杆菌和金黄色葡萄球菌具有明显的抑制作用，且对氨苄青霉素、四环素、庆大霉素、严迪(主要成分为罗红霉素)和头孢拉定有耐药特性。可用作微生态制剂和酸奶发酵剂的优良菌种。     

ICP-MS直接进样对大米酶解液中痕量硒的测定

建立电感耦合等离子体质谱(inductively coupled plasma-mass spectrometry,ICP-MS)直接进样测定大米酶解液中痕量硒的方法,并应用于体外模拟消化实验,得出硒的生物利用率。将样品酶解液离心过膜后ICP-MS直接进样测定硒含量,在0~160μg/L范围内线性相关系数为0.999 5,方法检出限为0.009μg/L,加标回收率在95.3%~102.8%之间,精密度为0.87%~4.48%。ICP-MS直接进样法操作简单环保,可作为大米等粮食酶解液中痕量硒的批量分析方法,并有望用于粮食类补硒食物的营养价值体外初评研究。     

Human Intestinal Dendritic Cells in Inflammatory Bowel Diseases

Inflammatory bowel disease (IBD), including Crohn's disease and ulcerative colitis, is a serious, costly, and persistent health problem with an estimated prevalence in Western countries around 0.5% of the general population; its socioeconomic impact is comparable with that for chronic diseases such as diabetes. Conventional treatment involves escalating drug regimens with concomitant side effects followed, in some cases, by surgical interventions, which are often multiple, mainly in Crohn's disease. The goal of finding a targeted gut‐specific immunotherapy for IBD patients is therefore an important unmet need. However, to achieve this goal we first must understand how dendritic cells (DC), the most potent antigen present cells of the immune system, control the immune tolerance in the gastrointestinal tract and how their properties are altered in those patients suffering from IBD. In this review, we summarize the current available information regarding human intestinal DC subsets composition, phenotype, and function in the human gastrointestinal tract describing how, in the IBD mucosa, DC display pro‐inflammatory properties, which drive disease progression. A better understanding of the mechanisms inducing DC abnormal profile in IBD may provide us with novel tools to perform tissue specific immunomodulation.     

Bioavailability of nutraceuticals: Role of the food matrix,processing conditions,the gastrointestinal tract,and nanodelivery systems

Nowadays, many consumers prefer foods with a high content of nutraceuticals that contribute to the prevention or healing of chronic diseases. Therefore, in recent years, more and more researchers have studied the bioefficiency, safety, and toxicity of nutraceutical‐enriched foods. The key stage of nutraceutical bioefficiency is oral bioavailability, which involves the following processes: the release of nutraceuticals from food matrices or nanocarriers in gastrointestinal fluids, the solubilization of nutraceuticals and their interaction with other components of gastrointestinal fluids, the absorption of nutraceuticals by the epithelial layer, and the chemical and biochemical transformations into epithelial cells. These processes are endogenous factors that greatly influence the bioavailability of nutraceuticals. In addition to endogenous factors, the bioavailability of nutraceuticals is also affected by exogenous factors, such as: physicochemical properties of nutraceuticals, food matrix, food processing and storage, and so forth. Both the endogenous and exogenous factors are comprehensively analyzed in this review. Thus, the physicochemical and enzymatic processes involved in food digestion are described, highlighting the role of each stage of gastrointestinal tract (mouth, stomach, and intestine) in nutraceuticals bioaccessibility. The structure and functions of the mucus and epithelial layers, the mechanisms involved in the active and passive transport of nutraceuticals through the cell membrane, and phase I and phase II metabolism reactions are also discussed. Finally, this review focuses on several types of bioactive‐loaded nanocarriers such as lipid‐based, surfactant‐based, and biopolymeric nanocarriers that improve the bioavailability of nutraceuticals.     

大豆脂肪酸对酿酒酵母酒精耐性的影响

通过向酒精发酵醪中添加不同量的大豆粉和脂肪酸，探讨大豆脂肪酸对酵母形态及酒精耐性的影响。结果表明，添加大豆粉可维持酵母细胞形态不变，降低残糖和提高酒精发酵的浓度，说明大豆粉可有效提高酵母菌的酒精耐性。大豆中的油酸、亚油酸可提高酵母菌的耐酒精性能，但不起维持细胞形态的作用。模拟大豆中主要脂肪酸含量，添加棕榈酸、油酸、亚油酸进行实验，结果表明，随添加量的增加，酒精浓度升高，但其作用小于添加脂肪酸含量相同的大豆粉的作用，且不能维持细胞形态不变。     

Fermentation characteristics and transit tolerance of Lactobacillus casei Zhang in reconstituted mare milk during storage

The fermentation characteristics of Lactobacillus casei Zhang in mare milk and transit tolerance during refrigerated storage for 28 days were evaluated. There were no dramatic changes in the viable counts of L. casei Zhang in the fermented mare milk samples during storage at various inoculation levels. L. casei Zhang showed good tolerance to the simulated transit juice and maintained high viability in mare milk (above 10⁸cfu/g) during storage. Our results showed that L. casei Zhang had good probiotic properties, and suggest that mare milk could serve as the vehicle for the delivery of L. casei Zhang.     

Fabrication of core–shell MIL-101(Cr)@UiO-66(Zr) nanocrystals for hydrogen storage

The fabrication of core–shell nanocrystals by incorporating microporous UiO-66 into mesoporous MIL-101 is reported. The growth of the core–shell MIL-101@UiO-66 nanocrystals was observed and supported by TEM and PXRD. The accessible pore volumes of the individual metal-organic framework (MOF) components and the core–shell hybrid crystals were also characterized. The hydrogen storage capacity exhibited by the resulting core–shell nanocrystals was 26% and 60% higher than those of pure phase MIL-101 and UiO-66, respectively. Finally, the fabricated core–shell MIL-101@UiO-66 structure exhibited a high degree of moisture tolerance.     

南瓜多糖的提取工艺及其降糖作用的研究

本文介绍了南瓜多糖的提取方法及其组分与理化性质,并将提取的南瓜多糖用于动物实验,结果证实了南瓜多糖的降糖作用。说明南瓜多糖在糖尿病辅助治疗方面存在着非常重要的价值。     

野生猕猴桃果酒酵母的筛选鉴定及耐受性的研究

文中主要筛选适合野生猕猴桃果酒发酵的酵母.通过显微镜观察和WL培养基的颜色变化,初筛出酵母菌136株.采用杜氏管发酵法,CO2失重比较法,猕猴桃果汁发酵法等从中复筛出两株发酵能力好、絮凝能力强、产香较好的菌株:YM-7和YM-210,初步鉴定均为酵母属的酿酒酵母.对YM-7菌种进行了耐受性研究,结果表明YM-7对葡萄糖、酒精度、酸度、NaC1和SO2具有较高耐受性,可作为野生猕猴桃发酵专用菌种或选育野生猕猴桃专用菌种的出发菌株.     

5株非酿酒酵母的耐受性及发酵特性研究

以陆生伊萨酵母（Issatchenkia terricola）、浅白隐球酵母（Cryptococcus albidus）、葡萄汁有孢汉逊酵母（Hanseniaspora uvarum）、美极梅奇酵母（Metschnikowia pulcherrima）、戴尔有孢圆酵母（Torulaspora delbruecki）为试材,分析了5株非酿酒酵母的生长特性、耐受性和碳源氮源同化能力及发酵速率。结果表明,戴尔有孢圆酵母的生长量较大,耐受的葡萄糖质量浓度为500 g/L、酒精体积分数为18%、SO2质量分数为420 mg/L,可同化氮源3种、碳源11种;陆生伊萨酵母的生长量较小,耐受的葡萄糖质量浓度为350 g/L、酒精体积分数为6%、SO2质量分数为120 mg/L,可同化氮源4种、碳源10种;其余3株非酿酒酵母的耐受及发酵特性优于陆生伊萨酵母低于戴尔有孢圆酵母;陆生伊萨酵母发酵速率在第2天达到最大值,其余4株酵母均在第3天达到发酵高峰。