HPAEC-PAD

HPAEC - PAD
  • 文章类型: Journal Article
    背景:\“FODMAPs\”(可发酵-寡头-,di-,单糖,和多元醇)是一组可发酵的碳水化合物和多元醇,它们在食品中大量扩散。尽管它们作为益生元的有益作用,患有肠易激综合征的人在食用这些碳水化合物时会出现症状。低FODMAP饮食似乎是针对症状管理提出的唯一可能的疗法。烘焙产品是FODMAP的常见来源,其模式和总量可能会受到其处理的影响。这项工作的目的是研究一些工艺参数,可以影响FODMAPs模式在烘焙产品的生产过程中。
    方法:将高效阴离子交换色谱与脉冲电流检测器(HPAEC-PAD)耦合用作面粉上碳水化合物评估分析的高选择性系统,面团,还有饼干.这些分析使用两个不同的柱进行,CarboPacPA200和CarboPacPA1对寡糖和简单糖分离具有选择性,分别。
    结果:选择Emmer和大麻粉制备面团,因为它们含有低寡糖含量。在不同的发酵时间使用两种不同的发酵混合物来评估获得低FODMAP饼干的最佳条件。
    结论:所提出的方法允许在饼干加工过程中进行碳水化合物评估,并允许选择合适的条件来获得低FODMAP产品。
    BACKGROUND: \"FODMAPs\" (fermentable-oligo-, di-, monosaccharides, and polyols) are a group of fermentable carbohydrates and polyols largely diffused in food products. Despite their beneficial effects as prebiotics, people affected by irritable bowel syndrome manifest symptoms when eating these carbohydrates. A low-FODMAP diet seems to be the only possible therapy proposed for symptom management. Bakery products are a common source of FODMAPs, whose pattern and total amount can be affected by their processing. This work aims at studying some of the technological parameters that can influence the FODMAPs pattern in bakery products during the production process.
    METHODS: high-performance anion exchange chromatography coupled to a pulsed amperometric detector (HPAEC-PAD) was used as a highly selective system for carbohydrates evaluation analyses on flours, doughs, and crackers. These analyses were performed using two different columns, the CarboPac PA200 and CarboPac PA1, which are selective for oligosaccharide and simple sugar separation, respectively.
    RESULTS: emmer and hemp flours were selected to prepare doughs as they contained low oligosaccharide content. Two different mixes of ferments were used at different times of fermentation to evaluate the best conditions to achieve low-FODMAP crackers.
    CONCLUSIONS: the proposed approach allows carbohydrate evaluation during crackers processing and permits the selection of opportune conditions to obtain low-FODMAP products.
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  • 文章类型: Journal Article
    准确确定马奶的大量营养素是研究牛奶成分如何影响小马驹生长和发育的前兆。本研究优化并验证了马乳寡糖的提取和定量方法,构成了马奶碳水化合物部分的一部分。母奶用氯仿和甲醇提取,使用多孔石墨化碳固相萃取(SPE)从碳水化合物部分中选择性分离低聚糖。通过优化的方法实现了牛奶低聚糖的良好回收率(在70%至100%之间)。这项研究还比较了使用傅立叶变换红外(FTIR)光谱与湿化学定量方法对蛋白质,脂肪,和乳糖。FTIR方法产生的蛋白质含量在统计上与湿化学方法相当,同时节省了分析师时间和消费品消费。相对于官方的湿化学方法,FTIR分析略微低估了马奶的脂肪含量,与方法之间的差异增加在较高的脂肪含量。FTIR还高估了马奶的乳糖含量,似乎产生了“乳糖”值,其中包括牛奶寡糖,因此代表了马奶的总碳水化合物(乳糖和牛奶寡糖)含量。
    Accurately determining the macronutrient profile of mare milk is a precursor to studying how milk composition affects foals\' growth and development. This study optimized and validated an extraction and quantification method for mare milk oligosaccharides, which make up a portion of the carbohydrate fraction of mare milk. Mare milk was extracted with chloroform and methanol, and oligosaccharides were selectively isolated from the carbohydrate fraction using porous-graphitized carbon solid-phase-extraction (SPE). Good recovery rates for milk oligosaccharides (between 70 and 100%) were achieved with the optimized method. This study also compared the use of Fourier-Transform infrared (FTIR) spectroscopy versus wet chemistry quantification methods for protein, fat, and lactose. The FTIR method produced statistically equivalent protein contents to the wet chemistry method, along with substantial savings in both analyst time and consumable consumption. FTIR analysis slightly underestimated the fat content of mare milk relative to the official wet chemistry method, with the difference between the methods increasing at higher fat contents. FTIR also overestimated the lactose content of mare milk and appeared to generate \"lactose\" values that included the milk oligosaccharides and thus represented the total carbohydrate (lactose and milk oligosaccharides) content of mare milk.
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  • 文章类型: Journal Article
    石榴在治疗许多疾病中的营养保健价值是有据可查的,并且与其在酚类化合物中的丰富度有关。本研究旨在评估新型石榴基因型(G1-G5)的营养和遗传多样性,与领先的商业石榴品种相比,即,\'奇妙\',\'Primosole\',\'DentediCavallo\'和\'Valenciana\'。对水果进行形态测量,伴随着化学表征(总酚含量,抗氧化活性,碳水化合物和矿物质)以及与类黄酮途径有关的四个新的多态性SSR标记的开发。品种在果实的重量和形状上表现出明显的变异性,以及阿拉伯的重量和果汁产量。在“奇妙”和G4中发现了最高的总酚含量和抗氧化活性,而在“DentediCavallo”中最低。此外,结果表明,石榴汁是矿物质的极好来源,尤其是钾,在器官功能中起着关键作用。新的类黄酮相关标记有效地区分了品种,具有与形态化学表征相同的多样性模式,因此,本研究中开发的SSRs可以作为鉴定具有相关营养性状的石榴品种的快速工具,比如调查的新基因型。
    The nutraceutical value of pomegranate in the treatment of many diseases is well-documented and is linked to its richness in phenolic compounds. This study aims to evaluate the nutraceutical and genetic diversity of novel pomegranate genotypes (G1-G5) in comparison to leading commercial pomegranate varieties, i.e., \'Wonderful\', \'Primosole\', \'Dente di Cavallo\' and \'Valenciana\'. Morphometric measurements were carried out on fruits, accompanied by chemical characterization (total phenolic content, antioxidant activity, carbohydrates and minerals) and the development of four new polymorphic SSR markers involved in the flavonoid pathway. The cultivars displayed a marked variability in the weight and shape of the fruits, as well as in the weight of the arils and juice yield. The highest level of total phenolic content and antioxidant activity was found in \'Wonderful\' and G4, while the lowest was in \'Dente di Cavallo\'. Furthermore, the results showed that pomegranate juice is an excellent source of minerals, especially potassium, which plays a key role in organ functioning. The new flavonoid-related markers effectively differentiated the cultivars with the same diversity pattern as morpho-chemical characterization, so the SSRs developed in the present study can be used as a rapid tool for the identification of pomegranate cultivars with relevant nutraceutical traits, such as the new genotypes investigated.
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  • 文章类型: Journal Article
    Shigella is a leading diarrheal cause of morbidity and mortality worldwide, especially in low- and middle-income countries and in children under five years of age. Increasing levels of antimicrobial resistance make vaccine development an even higher global health priority. S. flexneri serotype 6 is one of the targets of many multicomponent vaccines in development to ensure broad protection against Shigella. The O-antigen (OAg) is a key active ingredient and its content is a critical quality attribute for vaccine release in order to monitor their stability and to ensure appropriate immune response. Here, the optimization of two methods to quantify S. flexneri 6 OAg is reported together with the characterization of their performances. The optimized Dische colorimetric method allows a tenfold increment of the sensitivity with respect to the original method and is useful for fast analysis detecting selectively methyl-pentoses, as rhamnose in S. flexneri 6 OAg. Also, a more specific HPAEC-PAD method was developed, detecting the dimer galacturonic acid-galactosamine (GalA-GalN) coming from S. flexneri 6 OAg acid hydrolysis. These methods will facilitate characterization of S. flexneri 6 OAg based vaccines. The colorimetric method can be used for quantification of other polysaccharide containing methyl-pentoses, and the HPAEC-PAD could be extended to other polysaccharides containing uronic acids.
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  • 文章类型: Journal Article
    肠道疾病的全球传播,抗微生物治疗的选择越来越有限,并且需要有效的根除计划,导致对糖缀合物肠溶疫苗的需求增加,由病原体的碳水化合物膜成分制成,以及它们的精确表征。一组物理化学和免疫学测试用于完整的疫苗表征,并确保其一致性,效力,效力安全性和稳定性,遵循相关的世界卫生组织和药典指南。分析方法的变量要求与共轭结构有关,载体蛋白的性质和大小以及多糖的O-乙酰基含量。我们研究了一种关键的稳定性指示方法,该方法可测量肠沙门氏菌亚种肠伤寒血清型荚膜多糖的游离糖百分比,通过洗涤剂沉淀,解聚和HPAEC-PAD定量。结合现代计算方法,糖缀合物的更精确设计是可能的,允许提高溶解度,结构构象和稳定性,和抗原的免疫原性,这可能适用于广谱疫苗。需要更多的验证实验来建立最有效和最合适的糖缀合物分析方法,以使现有方案保持一致。尽管需要针对特定产品的方法,特别是对于更复杂的疫苗。本文概述了针对伤寒沙门氏菌和志贺氏菌物种的疫苗表征的当前和新兴分析方法。这项研究应有助于开发和许可旨在预防肠道疾病的新型糖缀合物疫苗。
    The global spread of enteric disease, the increasingly limited options for antimicrobial treatment and the need for effective eradication programs have resulted in an increased demand for glycoconjugate enteric vaccines, made with carbohydrate-based membrane components of the pathogen, and their precise characterisation. A set of physico-chemical and immunological tests are employed for complete vaccine characterisation and to ensure their consistency, potency, safety and stability, following the relevant World Health Organization and Pharmacopoeia guidelines. Variable requirements for analytical methods are linked to conjugate structure, carrier protein nature and size and O-acetyl content of polysaccharide. We investigated a key stability-indicating method which measures the percent free saccharide of Salmonella enterica subspecies enterica serovar Typhi capsular polysaccharide, by detergent precipitation, depolymerisation and HPAEC-PAD quantitation. Together with modern computational approaches, a more precise design of glycoconjugates is possible, allowing for improvements in solubility, structural conformation and stability, and immunogenicity of antigens, which may be applicable to a broad spectrum of vaccines. More validation experiments are required to establish the most effective and suitable methods for glycoconjugate analysis to bring uniformity to the existing protocols, although the need for product-specific approaches will apply, especially for the more complex vaccines. An overview of current and emerging analytical approaches for the characterisation of vaccines against Salmonella Typhi and Shigella species is described in this paper. This study should aid the development and licensing of new glycoconjugate vaccines aimed at the prevention of enteric diseases.
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  • 文章类型: Journal Article
    拟南芥种皮表皮细胞沉积了大量的粘液,由细胞壁成分果胶组成,半纤维素,和纤维素,在发育过程中进入原生质体。当成熟的种子水合时,粘液挤出在种子周围形成凝胶状胶囊。确定挤出粘液和整个种子的单糖组成是表征具有改变的粘液组成的种皮发育过程和突变体的基本技术。该协议涵盖了植物的生长,以产生适合分析的种子,使用水和碳酸钠提取挤出的粘液(用于粘液释放受损的突变体),从全种子中提取醇不溶性残留物(AIR)。然后用硫酸水解制备的多糖,水解包括纤维素在内的所有多糖。使用与脉冲安培检测(HPAEC-PAD)偶联的高效阴离子交换色谱实现所得单糖的灵敏和可再现的定量。
    Arabidopsis seed coat epidermal cells deposit a significant quantity of mucilage, composed of the cell wall components pectin, hemicellulose, and cellulose, into the apoplast during development. When mature seeds are hydrated, mucilage extrudes to form a gelatinous capsule around the seed. Determining the monosaccharide composition of both extruded mucilage and whole seeds is an essential technique for characterizing seed coat developmental processes and mutants with altered mucilage composition. This protocol covers growth of plants to produce seeds suitable for analysis, extraction of extruded mucilage using water and sodium carbonate (used for mutants with impaired mucilage release), and extraction of alcohol insoluble residue (AIR) from whole seeds. The prepared polysaccharides are then hydrolyzed using sulfuric acid, which hydrolyses all polysaccharides including cellulose. Sensitive and reproducible quantification of the resulting monosaccharides is achieved using high-performance anion exchange chromatography coupled with pulsed amperometric detection (HPAEC-PAD).
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  • 文章类型: Journal Article
    双生效应是评价益生元活性的一个主要目标。本文提供了双歧杆菌和粪便微生物群的pH控制分批工艺。双歧杆菌的生长,碳水化合物分解和消耗,有机酸生产,和参与二水解的特定糖基水解酶的活性,寡头-,或多糖被用来研究和比较双歧杆菌对候选益生元的底物偏好。
    Bifidogenic effect is a main target for the assessment of prebiotic activity. pH-controlled batch processes of bifidobacteria and fecal microbiota are herein presented. Growth of bifidobacteria, carbohydrate breakdown and consumption, organic acid production, and activity of specific glycosyl hydrolases involved in the hydrolysis of di-, oligo-, or polysaccharides are exploited to study and compare substrate preference of bifidobacteria for candidate prebiotics.
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  • 文章类型: Journal Article
    Bifidobacteria are able to utilize a diverse range of host-derived and dietary carbohydrates, the latter of which include many plant-derived oligo- and polysaccharides. Different bifidobacterial strains may possess different carbohydrate utilization abilities. These metabolic abilities can be studied using classical bacterial growth assessment methods, such as measurement of changes in optical density or acidity of the culture in the presence of the particular carbohydrate to generate growth and acidification curves, respectively. Scientists may also be interested in the growth rate during the exponential growth phase, and the maximum OD that is reached on a particular sugar, or the length of the lag phase. Furthermore, high-performance liquid chromatography (HPLC) and high-performance anion exchange chromatography coupled to pulsed amperometric detection (HPAEC-PAD) are extensively used in carbohydrate and metabolic end-product analysis due to their versatility and separation capabilities.
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  • 文章类型: Journal Article
    通过葡聚糖酶的葡聚糖水解应用于制糖工业和医疗部门,但它也有很高的潜力用于结构分析的葡聚糖。然而,葡聚糖酶由几种生物体产生,因此它们的性质不同。这项研究的目的是比较研究从线性以及O3和O4分支的葡聚糖与不同的葡聚糖酶孵育获得的产物模式。为此,克隆了编码拟杆菌和唾液链球菌的葡聚糖酶的基因,并在大肠杆菌中异源表达。这两种重组酶以及来自Chaetomiumsp的两种商业葡聚糖酶。和青霉菌sp.随后用于水解结构不同的葡聚糖。通过HPAEC-PAD详细研究了水解产物。对于来自Chaetomiumsp。的葡聚糖酶。,青霉。,和拟杆菌,异麦芽糖是线性葡聚糖水解的最终产物,而青霉属。葡聚糖酶导致异麦芽糖和异麦芽四糖。此外,后一种酶与异麦芽三糖孵育时也催化歧化反应。对于O3-和O4-支链葡聚糖,真菌葡聚糖酶产生的寡糖模式与细菌酶明显不同。总的来说,可以通过选择正确的酶以及定义的酶活性来调整产品模式。
    Dextran hydrolysis by dextranases is applied in the sugar industry and the medical sector, but it also has a high potential for use in structural analysis of dextrans. However, dextranases are produced by several organisms and thus differ in their properties. The aim of this study was to comparatively investigate the product patterns obtained from the incubation of linear as well as O3- and O4-branched dextrans with different dextranases. For this purpose, genes encoding for dextranases from Bacteroides thetaiotaomicron and Streptococcus salivarius were cloned and heterologously expressed in Escherichia coli. The two recombinant enzymes as well as two commercial dextranases from Chaetomium sp. and Penicillium sp. were subsequently used to hydrolyze structurally different dextrans. The hydrolysis products were investigated in detail by HPAEC-PAD. For dextranases from Chaetomium sp., Penicillium sp., and Bacteroides thetaiotaomicron, isomaltose was the end product of the hydrolysis from linear dextrans, whereas Penicillium sp. dextranase led to isomaltose and isomaltotetraose. In addition, the latter enzyme also catalyzed a disproportionation reaction when incubated with isomaltotriose. For O3- and O4-branched dextrans, the fungal dextranases yielded significantly different oligosaccharide patterns than the bacterial enzymes. Overall, the product patterns can be adjusted by choosing the correct enzyme as well as a defined enzyme activity.
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  • 文章类型: Journal Article
    In this study, starches from underground stems of Trimezia juncifolia were evaluated during dry season (DSS), wet season (WSS) and sprouting (SS). Results evidenced that drought stress did not interfere with the yield, amylose content and degree of polymerization (DP) of amylopectin. However, the extraction yield in SS was 58% lower, being observed and increase of 7.5% in the content of amylose, and 13.5% in DP values for SS amylopectin, with a predominance of A-chains. The amount of total sugar, the starch granules size as well as solubility and swelling properties varied as function of the phenological status. Also, starch granules changed from A-type polymorph in DSS and SS to a CA-type in WSS. Nevertheless, it was observed a crystallinity reduction from 56% in DSS to 37.1% in SS. In addition, thermograms evidenced the presence of amylose-lipid complexes, with endothermic transition temperatures being affected by drought stress and sprouting. Finally, results demonstrate that underground stems from T. juncifolia have adaptative strategies involving changes in the morphological and physicochemical properties of the starch granules.
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