低聚木糖在乳制品中的应用发展概况

介绍低聚木糖的一些基本功能,从低聚木糖在乳制品中的应用出发,详细的说明了低聚木糖添加到乳制品中的优点.同时又介绍了低聚木糖在乳制品应用中的国内外发展概况以及低聚木糖在乳品行业的发展方向.     

低聚木糖的生产和应用

由木糖苷组成的低聚糖称为低聚木糖，该糖具有很多功能特性。本文综述了采用化学和酶法等方法由木质纤维材料制取低聚木糖，低聚木糖的精制纯化，以及低聚木糖在食品添加剂方面的应用，其中特别介绍了低聚木糖的保健效果。     

功能性低聚木糖豆浆饮品的开发

介绍了低聚木糖和豆浆的功效及几种低聚木糖豆浆类饮品的制作方法,并展望了低聚木糖豆浆的开发前景。     

保健食品中低聚木糖含量测定

目的建立一种含有多糖纤维和低聚木糖的保健食品中低聚木糖含量测定的方法。方法用无水乙醇沉淀多糖纤维,将多糖纤维从试样中分离,用12%稀硫酸溶液将试样中的低聚木糖酸解为木糖,10%氢氧化钠溶液调p H至中性,选择适合的糖柱,以木糖为标样,外标法计算低聚木糖的含量(以木糖通过转换系数计)。结果酸解后试样中木糖浓度在0.0378~0.4536 mg/m L的范围内与峰面积的线性关系良好,相关系数r0.999。在3水平不同浓度木糖标准品添加下,木糖的回收率为97.9%。结论该方法操作简便、重现性好,适用于添加了多糖纤维和低聚木糖的保健食品中低聚木糖的含量测定。     

低聚木糖的应用研究和产品开发进展

低聚木糖是由2~7个木糖分子以β–1,4糖苷键连接而成的功能性低聚糖,具有低热值、良好的稳定性、显著的双歧杆菌增殖效果和抑制病原菌等特性。近年来,低聚木糖作为一种新型的添加剂,其应用已经越来越广泛,越来越多的功能性食品和饲料等产品中添加了低聚木糖作为功能成分。该文介绍了低聚木糖的主要功能特性,以及在食品工业、饲料工业、医药以及农业等领域的应用研究和产品开发现状,并展望了低聚木糖产品的研发趋势及前景。     

硫酸水解法测定果胶中低聚木糖含量及方法学验证

关于低聚木糖的检测方法现在在<药典>中没有规定,山东龙力生物科技有限公司针对低聚木糖相关产品的检测方法作了大量的工作.并参加了低聚木糖行业标准的制定.此文介绍了硫酸水解法测定低聚木糖的方法.并对方法学的建立作了详细的阐述.     

不同聚合度低聚木糖体外清除自由基活性研究

通过研究不同聚合度的粗低聚木糖(LL、ML、HL)及其中所含的木糖对羟自由基(·OH)清除活性的影响,对纯低聚木糖的平均聚合度与活性间的关系进行了评价。实验结果表明.粗低聚木糖对羟自由基(·OH)具有较好的清除活性。其中。高聚合度的粗低聚木糖(HL)对羟自由基(·OH)的清除活性最显著,IC_(50)约为14 mg/mL.而木糖对羟自由基(·OH)无清除活性,说明纯低聚木糖的平均聚合度越高,清除羟自由基(·OH)作用越显著。对木糖及不同聚合度粗低聚木糖+DPPH自由基进行紫外扫描.探讨纯低聚木糖对DPPH自由基的清除作用,结果表明,木糖及纯低聚木糖对DPPH自由基均没有清除能力。     

低聚木糖在动物饲料中的应用研究进展

介绍低聚木糖的主要理化特性和生理功能,综述近几年来低聚木糖在动物饲料中的应用研究进展,提出了目前存在的问题,并展望了低聚木糖在动物饲料中应用的潜力。     

低聚木糖在保健食品中的应用

该文概述了低聚木糖的化学结构和加工特性,对低聚木糖的保健功能进行了重点阐述,并简要说明了低聚木糖的工业制备和在保健食品领域的应用前景。     

玉米芯生产低聚木糖脱色工艺研究

研究了玉米芯生产低聚木糖的脱色工艺。采用由木聚糖酶和纤维素酶组成的复合酶对玉米芯进行水解生产低聚木糖,通过活性炭对低聚木糖提取液脱色工艺进行优化。结果表明,低聚木糖活性炭脱色的最佳工艺条件为:温度为40℃,脱色时间30 min,活性碳添加量20%,可溶性总糖含量11 mg/m L。产品脱色率可达68.93%,还原糖损失率为34.75%,脱色后的低聚木糖溶液经乙醇沉淀后制备低聚木糖,得率为11.58%。     

Outcome of clinical mastitis in dairy heifers assessed by reexamination of cases one month after treatment

Heifers that were treated for clinical mastitis prior to parturition or within 14 d postpartum were reexamined approximately 1 mo after treatment. Clinical examination of the heifers and microbiological examination of quarter milk samples were carried out on both occasions. Of the 1000 heifers included in the study, 10.9% were culled within 28 d after treatment. Udder damage caused by mastitis was the only or main reason for culling in 96% of those heifers. In comparison, 4.5% of nonmastitic heifers from the same herds were culled within 30 d postpartum. Twenty-five percent of those heifers that were not culled at d 28 after treatment had at least one nonfunctional quarter at that time. One thousand one hundred twenty-two quarters that were clinically affected at the time of treatment were reexamined; 22% were nonfunctional, 14% were still affected by clinical mastitis, 12% had subclinical mastitis, 5% had a latent infection with coagulase-positive staphylococci or Streptococcus dysgalactiae, and 46% were bacteriologically negative and had a normal cell count at the time of reexamination. High percentages of nonfunctional quarters were observed among those quarters that were infected with Arcanobacterium pyogenes or with coagulase-positive staphylococci at treatment. When all quarters that were clinically affected at treatment were considered, 40% of quarters were cured and were still in lactation at reexamination. Quarters infected with coagulase-negative staphylococci had a higher cure rate than quarters infected with other organisms. At reexamination, clinical signs of thelitis were observed in many of those quarters that were nonfunctional following the episode of clinical mastitis and also in 25% of lactating quarters in which clinical mastitis persisted.     

Temperatures and ages of boxed beef packed and distributed in Canada

Boxes of beef were examined when product was packed and when boxes were loaded out of five packing plants, when boxes were loaded into and loaded out of seven refrigerated warehouses, and when boxes were received and opened at 21 retail stores. At each stage of handling at each facility, the boxes to be examined were selected at random. For each selected box, the temperature of product at the centre of the box was measured, and the date of packing and the plant of origin were noted. When cuts were packed, the minimum, median and maximum temperatures were about 2, 6 and 18 °C, respectively. Temperatures were successively lower when boxes were loaded out of packing plants, into warehouses and out of warehouses. When loaded out of warehouses, the minimum, median and maximum temperatures were about −2, 1 and 8 °C, respectively. The ranges of temperatures were similar, but the median temperatures were about 2 or 1.5 °C, respectively, when boxes were received at or were opened at retail stores. At packing plants and warehouses, the temperatures of manufacturing and ground beef were lower than those of cuts, but at the retail store the temperatures of all types of product were similar. When boxes were opened at retail stores, the minimum, median and maximum ages of cuts were about 2, 20 and 130 days, respectively; and the corresponding ages for manufacturing and ground beef were 2, 7 and 56 days, respectively. The data indicate that boxed beef is generally cooled to and maintained at temperatures within the range sought by the meat industry. However, cooling to chiller temperatures of product that is packed while warm can take several days; and some product is held for times that are excessive in view of the temperatures of boxed beef.     

水牛乳中可培养乳酸菌多样性分析

采用传统分离培养方法,从三品杂交生水牛奶混合样品中,分离出105株乳酸菌,通过形态、生理生化、API细菌鉴定系统及16S rDNA基因序列分析方法对各菌株属种进行鉴定。16S rRNA序列分析结果显示,105株菌共分为5个属8个种,呈现较为丰富的乳酸菌多样性,具体数量分布为乳酸乳球菌21株,植物乳杆菌19株,格氏乳球菌17株,乳明串珠菌13株,食窦魏斯氏菌11株,肠膜明串珠菌8株,类肠膜魏斯氏菌6株,嗜热链球菌5株,糊精乳杆菌5株。由此可知,水牛乳中可培养乳酸菌优势菌群的主次关系为：乳酸乳球菌（Lactococcus lactis）＞植物乳杆菌（Lactobacillus plantaru）＞格氏乳球菌（Lactococcus garvieae）＞乳明串珠菌（Leuconostoc lactis）＞食窦魏斯氏菌（Weissella cibaria）,此为后续开发水牛乳中优势乳酸菌资源提供了良好的理论基础。     

新疆乳品中乳酸菌的多样性及耐药性分析

从新疆北部地区采集的样品中分离出103株乳酸菌并进行生理生化表型鉴定,对这些乳酸菌进行16S rRNA基因序列测序,构建系统发育树发现分离的乳酸菌主要为5个属分别为乳杆菌属、肠球菌属、乳球菌属、魏斯式菌属、明串珠菌属。采用纸片扩散法（K-B）研究不同属中不同乳酸菌对8种常见抗生素的耐药性分析。耐药性研究表明,分别有6株对链霉素、新霉素有耐药性,5株对红霉素有耐药性,7株对卡那霉素有耐药性,8株全部对萘啶酸具有耐药性,4株对万古霉素、四环素具有耐药性,2株对头孢唑肟存在耐药性。     

芦苇叶类黄酮高效液相色谱分析

目的：分析芦苇叶类黄酮的组分。方法：制备芦苇叶类黄酮提取浓缩过程中形成的析出物和浓缩液再经大孔树脂纯化后产生的初纯物,优化两种样品中类黄酮苷转化为苷元的水解条件,采用高效液相色谱(HPLC)法测定两种样品和其水解样品类黄酮的组分。结果：析出物和初纯物的总黄酮含量分别为57.1%和18.5%,酸浓度1.4mol/L、温度80～90℃条件下水解4h可获得相对最好的水解效果;HPLC测定表明,析出物含32种组分,其中7种得到确定,初纯物含22种组分,其中5种得到确定;水解析出物含28种组分,其中7种得到确定,水解初纯物含25种组分,其中7种得到确定。结论：芦苇叶含有芦丁、野黄芩苷、橙皮苷、木犀草素、槲皮素、芹菜素、山奈酚、异鼠李素(或橙皮素)、异甘草素和黄芩素,其中芹菜素含量最高,还有许多未确定的类黄酮。     

Sensitivity of Methods of Variance Component Estimation to Culling Type of Selection

Two pseudoexpectation methods of variance component estimation were examined for selection bias from culling and were compared with Henderson's simple method and restricted maximum likelihood. Milk yield data were simulated for 100 herds, 50 sires, and approximately 2000 cows per replicate. Heritability was .25, and repeatability was .50. Each cow had two records. Twenty replicates were made. Two data sets were created; one was unselected and included both records of the cow, and the second excluded second records of cows with first records below the herd mean. Sire, cow, and error variances were estimated according to a mixed model that included fixed herd, parity, and random sire, cow, and error effects. Estimates of sire, cow, and error variances and heritability and repeatability were unbiased and were similar for all methods for unselected data. For selected data, sire and cow variances were overestimated and error variances were underestimated with Henderson's simple method and the pseudoexpectation methods. Accordingly, heritabilities and repeatabilities were overestimated. Biases were greatest for Henderson's simple method and differences between the two pseudoexpectation methods were small. With restricted maximum likelihood, sire variances were unbiased but error variances were slightly overestimated and cow variances underestimated. Use of restricted maximum likelihood is preferred with selected data.     

水性聚氨酯涂饰剂的性能分析

对几种水性聚氨酯涂饰剂的性能进行了多方面的测定分析,包括聚氨酯涂饰剂的含固量和pH值、聚氨酯涂饰剂膜的感观和机械性能、聚氨酯涂饰剂运用于涂饰中时涂层的性能。通过测定分析了解了这些聚氨酯涂饰剂的优缺点,以及它们用于皮革涂饰工艺中时所适用的涂饰种类。     

Isolation and identification of nontuberculous mycobacteria from foods as possible exposure sources

A variety of foods collected from local supermarkets and produce stands were examined as possible sources of nontuberculous mycobacterial exposure. Food samples were combined with sterile ultrapure water and manually shaken. To remove large particles, the suspensions were filtered through a sterile strainer, centrifuged, and the supernatants were discarded. The food pellets were stored at -75 degrees C. The pellets were treated with either oxalic acid or sodium hydroxide-sodium citrate solutions to reduce contamination by nonmycobacterial organisms. Decontaminated pellets were cultured on both Middlebrook 7H10C agar and Middlebrook 7H10C agar with supplemental malachite green. Plates were observed for growth at 2 and 8 weeks. Isolates demonstrating acid-fastness were identified to species using polymerase chain reaction and restriction enzyme analysis. Nontuberculous mycobacteria (NTM) were recovered from 25 of 121 foods. Six different species of NTM were isolated, the most predominant being Mycobacterium avium.     

江西省食源性沙门菌血清分型及脉冲场凝胶电泳指纹图谱研究

研究江西省食源性沙门菌的血清型,用脉冲场凝胶电泳(PFGE)方法对优势血清型进行分子分型,建立江西省食源性沙门菌PFGE指纹图谱资料库,为食源性疾病溯源提供数据。方法 对136株食源性沙门菌进行血清分型,对其中优势血清型德尔卑沙门菌菌株进行PFGE分型,获得分子分型指纹图谱,运用Bionumerics v6.6软件进行聚类分析。结果 136株沙门菌分离株血清群以B群为主,优势血清型主要是德尔卑沙门菌(49.26%),67株德尔卑沙门菌可分为41个型别的PFGE指纹图谱(相似值100%的为同一PFGE型别),主要集中在3个型别中。结论 江西省食源性沙门菌血清型分布呈多样性,优势血清型是德尔卑沙门菌,生肉制品是其主要的来源,同种血清型别的PFGE指纹图谱无相关性。     

豆类纤维素和蛋白质对豆淀粉理化性质影响研究

选取豌豆、红豆和绿豆三种样品豆,并分别制备豆全粉、除纤维素豆粉、豆淀粉三种样品,研究它们溶胀度、可溶指数、直链淀粉含量、糊化性、质构性等性质。结果表明,三种样品豆的豆全粉、除纤维素豆粉、豆淀粉的粘度差异较大,其中以豆淀粉粘度最高,除纤维素豆粉次之,豆全粉粘度最低;豆淀粉硬度、胶粘性和咀嚼性高于豆全粉和除纤维素豆粉;随温度升高,三种样品豆的豆全粉、除纤维素豆粉、豆淀粉溶胀度和可溶指数均呈现递增趋势,其中豆全粉可溶指数明显高于除纤维素豆粉和豆淀粉;在较高温度下,豆淀粉溶胀度要高于除纤维素豆粉和豆全粉。