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1.
酪蛋白糖巨肽的生物学活性   总被引:4,自引:0,他引:4  
酪蛋白糖巨肽(Caseino Glycomacropeptide,简称CGMP)主要是κ-酪蛋白经凝乳酶降解产生的一类含有糖链的多肽,具有许多的生理活性功能和独特的营养特性,可广泛地应用于保健食品和医药品.综述了CGMP的一些生理功能研究进展以及其生产制备工艺的现状,同时也介绍了它在食品和医药品中的应用前景.  相似文献
2.
本文探讨了利用了(NH4)2SO4分级沉淀、透析脱盐及Q—Sepharose FF层析分离纯化酩蛋白的胃蛋白酶水解物中的CGMP的工艺。结果表明:采用60%饱和度的(NH4)2SO4盐析,可从上清液中直接回收高纯度CGMP,得率为0.71%。低饱和度的(NH4)2SO4可有效脱除杂蛋白。脱盐粗提物CGMP Q—Sepharose FF层析条件为:pH8.5、20mmol/L Tris缓冲液平衡上样,用含0.3mol/L NaCl、20mmol、pH7.1的Tris缓冲液洗脱:浓缩物最大上样量为34.2mg蛋白/ml树脂。利用优化的工艺对水解液层析纯化,纯化产物得率约为2.19%(以酪蛋白汁),总结合态唾液酸回收率为87.4%(以酶解液中的唾液酸汁),糖基化度可提高到0.472以上。整个工艺路线简使、快捷、成本较低,适合工业化生产。  相似文献
3.
由鸡蛋黄粉制备含唾液酸的水解液   总被引:2,自引:1,他引:1  
研究了从鸡蛋黄粉制备含有唾液酸的水解浓缩液(可从中进一步精制出唾液酸成品)的方法,包括蛋黄粉的脱脂方法,脱脂蛋黄粉水解条件的优化,水解清液的超滤和纳滤浓缩、除盐。最终制得的水解液中含唾液酸1200μg/mL,相当于从每克干重的脱脂蛋黄粉中游离出了1.67mg的唾液酸。  相似文献
4.
Two methods for determining sialic acid in infant formulas – spectrophotometry and HPLC with fluorescence detection – have been optimised and validated, the first one allows to determine total sialic acid while the second allows to differentiate the two main forms of sialic acid (N-acetylneuraminic acid (Neu5Ac) and N-glycolylneuraminic acid (Neu5Gc)). A common sample preparation procedure (hydrolysis and purification) for both methods has been proposed. The linearity (from 6 to 150 μg of total sialic acid in the assay for spectrophotometry, and from 12.5 to 250 ng and 1 to 5 ng of Neu5Ac and Neu5Gc, respectively, for HPLC) is adequate. The detection and quantification limits (0.29 and 0.97 mg of total sialic acid/L of reconstituted sample, respectively, for spectrophotometry, and 0.03 and 0.08 mg Neu5Ac/L; 0.003 and 0.009 mg Neu5Gc/L of reconstituted sample, respectively, for HPLC) are low enough for the determination of sialic acid in infant formulas. The precision of both methods, expressed as relative standard deviation, is less than 6%, and the accuracy evaluated by recovery assays show 104% recovery for spectrophotometry; 95% for Neu5Ac and 109% for Neu5Gc for HPLC. Samples analysed show no significant differences (α < 0.05) attributable to the method used; consequently, both of them could be applied after common sample preparation, the choice of technique depending on the facilities available in the laboratory.  相似文献
5.
Milk ingredients as nutraceuticals   总被引:1,自引:0,他引:1  
Cow's milk is considered as a basic food in many diets, and is rich in a variety of essential nutrients. With today's sophisticated analytical, biochemical and cell-biological research tools, the presence of many other (minor) compounds with biological activity has been demonstrated. Achievements in separation techniques in the dairy industry and enzyme technology offer opportunities to isolate, concentrate or modify these compounds, so that their application in functional foods, dietary supplements, nutraceuticals and medical foods has become possible.
Within the sequence of amino acids of a dietary protein, specific peptides may be located with specific biological activity. Peptides from casein may be used to enhance the solubility of minerals such as calcium and zinc—and hence increase the bioavailability of these minerals—or to reduce the activity of the angiotensin-converting enzyme, which is involved in vasoconstriction and (hence) blood pressure.
Immunoglobulins from vaccinated cows may be considered as natural antimicrobials with certain advantages over synthetic antibiotics. Lactoferrin is an example of a minor milk protein that has been studied in great detail: it is becoming increasingly clear that it is important for the nonspecific defence against bacteria, fungi and viruses. Oligosaccharides, glycolipids and glycoproteins containing sialic acid residues may have a role as anti-infectives.
Components such as growth factors may also be considered for future product development, because of the economies of scale used in the dairy industry.  相似文献
6.
聚唾液酸的水解与唾液酸的纯化   总被引:1,自引:0,他引:1  
在HPLC分析唾液酸质量分数的基础上,选择盐酸作为大肠杆菌发酵液中聚唾液酸的水解用酸.在85℃水浴.盐酸浓度为0.1mol/L的条件下,水解2h,水解率平均可达95%以上.水解液中和过滤后,用离子交换色谱分离与冷冻干燥得到唾液酸产品.质谱及HPLC分析证实所得产品中主要成分是N 乙酰神经氨酸,其纯度达96.4%.  相似文献
7.
白燕与血燕的营养成分分析和比较   总被引:1,自引:0,他引:1  
为分析和比较白燕与血燕的营养成分,分别采用凯氏定氮法、邻苯二甲醛-氯甲酸芴甲酯(OPA—FMOC)柱前衍生反相高效液相色谱法、柱前衍生二极管阵列/荧光检测器串联反相高效液相色潜法和电感耦合等离子体质谱法(ICP—MS)等方法测定了白燕与血燕的蛋白质含量、氨基酸组成及比例、唾液酸含量、无机元素含量。结果表明:白燕蛋白质含量为56.5%,氨基酸总量49.22%,其中必需氨基酸占氨基酸总量的58.0%,唾液酸含量占干重15.3%。血燕蛋白质含量为55.0%,氨基酸总量44.16%,必需氨基酸占氨基酸总量的57.9%,唾液酸含量约为13.3%。两种燕窝中蛋白质、氨基酸含量均较高,必需氨基酸占氨基酸总量50%以上.唾液酸含量均大于10%,无机元素种类丰富。白燕的蛋白质含量、氨基酸总量、唾液酸含量比血燕略高.但两者不存在明显差异,两种燕窝中无机元素含量略有差异.该结果为燕窝产品的深入研究提供了重要依据和实验思路。  相似文献
8.
高效液相色谱法测定母乳中唾液酸含量   总被引:1,自引:0,他引:1  
建立荧光高效液相色谱(fluorescence detector-high performance liquid chromatography,HPLC-FLD)测定母乳中唾液酸N-乙酰神经氨酸(N-acetylneuraminic acid,Neu5Ac)和N-羟乙酰神经氨酸(N-glycolyl neuraminic acid,Neu5Gc)含量的分析方法。利用酸水解法释放出母乳中的唾液酸,以4,5-亚甲二氧基-1,2-邻苯二胺盐(4,5-methylenedioxy-1,2-phenylenediamine dihydrochloride,DMB)为衍生化试剂,50℃避光衍生150min,采用荧光高效液相色谱仪检测。色谱条件:LiChrosorb RP-18柱(250mm×4mm,5μm),流动相为甲醇-乙腈-超纯水(7:8:85),流速0.9mL/min,进样体积10μL,柱温30℃,荧光检测器激发波长373nm,发射波长448nm。结果表明:唾液酸在50~400μmol/L范围内与唾液酸峰面积的线性关系良好,平均回收率为94.0%,精密度的相对标准偏差(relative standard devia...  相似文献
9.
唾液酸的研究进展   总被引:1,自引:0,他引:1  
唾液酸是一系列的9-碳酸性单糖,是高等动物和某些微生物具有的重要分子。唾液酸在原核和真核生物的生理反应和特征方面具有重要的作用。唾液酸与复杂的糖结合并占据了重要的位置,特别是在细胞膜上。它们保护了生物大分子和细胞免受酶和免疫的攻击。由于其结构的高度多样性,其生物合成机制也是复杂的。本文综述了近年来唾液酸的制备、分离纯化、检测方法、生物活性和应用现状的研究进展,并对其未来的发展方向进行了展望。  相似文献
10.
燕窝及其伪品鉴定方法研究   总被引:1,自引:0,他引:1  
分别利用性状、电泳、紫外光谱法及唾液酸含量HPLC分析等方法,研究燕窝及其伪品的鉴定技术。结果表明,真燕窝在278nm有最大紫外吸收,含有唾液酸,电泳谱图与伪品差异明显等特点,利用上述方法可以综合鉴定燕窝真伪及不同品质的燕窝,为制定燕窝国家标准提供依据。  相似文献
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