50 / 100 assays (manual) / 550 assays (microplate) / 550 assays (auto-analyser)
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|Content:||50 / 100 assays (manual) / 550 assays (microplate) / 550 assays (auto-analyser)|
|Storage Temperature:|| Short term stability: 2-8oC, |
Long term stability: See individual component labels
|Stability:||> 6 months under recommended storage conditions|
|Assay Format:||Spectrophotometer, Microplate, Auto-analyser|
|Linear Range:||5 to 100 µg of L-rhamnose per assay|
|Limit of Detection:||~ 1.2 mg/L|
|Reaction Time (min):||~ 5 min at 25oC or ~ 4 min at 37oC|
|Application examples:||Hydrolysates of plant material and polysaccharides, culture media / supernatants and other materials.|
|Method recognition:||Novel method|
The L-Rhamnose Assay Kit for the measurement of L-rhamnose in plant extracts, culture media/supernatants and other materials is a simple, rapid method.
L-Rhamnose occurs naturally in the L-form and is commonly present as a component of the carbohydrate moiety of eukaryotic glycoproteins and in plant cell wall polysaccharides. The most abundant occurrence of L-rhamnose is within the pectic fraction of plant cell wall polysaccharides. L-Rhamnose is commonly used as a non-metabolisable marker along with lactulose for dual-permeability testing in the diagnosis of intestinal diseases such as Crohn’s disease or coeliac disease.
Note for Content: The number of manual tests per kit can be doubled if all volumes are halved. This can be readily accommodated using the MegaQuantTM Wave Spectrophotometer (D-MQWAVE).
View more of our monosaccharide and disaccharide assay kits.
- Very cost effective
- All reagents stable for > 2 years after preparation
- Only test kit available
- Simple format
- Rapid reaction (~ 5 min at 25oC or ~ 4 min at 37oC)
- Mega-Calc™ software tool is available from our website for hassle-free raw data processing
- Standard included
- Suitable for manual, microplate and auto-analyser formats
Measurement of available carbohydrates in cereal and cereal products, dairy products, vegetables, fruit and related food products and animal feeds: First Action 2020.07.
McCleary, B. V. & McLoughlin, C. (2021). Journal of AOAC International, qsab019.
Background: The level of available carbohydrates in our diet is directly linked to two major diseases; obesity and Type II diabetes. Despite this, to date there is no method available to allow direct and accurate measurement of available carbohydrates in human and animal foods. Objective: The aim of this research was to develop a method that would allow simple and accurate measurement of available carbohydrates, defined as non-resistant starch, maltodextrins, maltose, isomaltose, sucrose, lactose, glucose, fructose and galactose. Method: Non-resistant (digestible) starch is hydrolysed to glucose and maltose by pancreatic α-amylase and amyloglucosidase at pH 6.0 with shaking or stirring at 37°C for 4 h. Sucrose, lactose, maltose and isomaltose are completely hydrolyzed by specific enzymes to their constituent monosaccharides, which are then measured using pure enzymes in a single reaction cuvette. Results: A method has been developed that allows the accurate measurement of available carbohydrates in all cereal, vegetable, fruit, food, and feed products, including dairy products. Conclusions: A single-laboratory validation was performed on a wide range of food and feed products. The inter-day repeatability (%RSDr) was <3.58% (w/w) across a range of samples containing 44.1 to 88.9% available carbohydrates. The LOD and LOQ obtained were 0.054% (w/w) and 0.179% (w/w), respectively. The method is all inclusive, specific, robust and simple to use. Highlights: A unique method has been developed for the direct measurement of available carbohydrates, entailing separate measurement of glucose, fructose and galactose; information of value in determining the glycemic index of foods.Hide Abstract
Stimuli-responsive vesicles as distributed artificial organelles for bacterial activation.
Gispert, I., Hindley, J. W., Pilkington, C. P., Shree, H., Barter, L. M., Ces, O. & Elani, Y. (2022). Proceedings of the National Academy of Sciences, 119(42), e2206563119.
Intercellular communication is a hallmark of living systems. As such, engineering artificial cells that possess this behavior has been at the heart of activities in bottom-up synthetic biology. Communication between artificial and living cells has potential to confer novel capabilities to living organisms that could be exploited in biomedicine and biotechnology. However, most current approaches rely on the exchange of chemical signals that cannot be externally controlled. Here, we report two types of remote-controlled vesicle-based artificial organelles that translate physical inputs into chemical messages that lead to bacterial activation. Upon light or temperature stimulation, artificial cell membranes are activated, releasing signaling molecules that induce protein expression in Escherichia coli. This distributed approach differs from established methods for engineering stimuli-responsive bacteria. Here, artificial cells (as opposed to bacterial cells themselves) are the design unit. Having stimuli-responsive elements compartmentalized in artificial cells has potential applications in therapeutics, tissue engineering, and bioremediation. It will underpin the design of hybrid living/nonliving systems where temporal control over population interactions can be exerted.Hide Abstract
Utilization of stalk waste separated during processing of sun-dried figs (Ficus carica) as a source of pectin: Extraction and determination of molecular and functional properties.
Çavdaroğlu, E. & Yemenicioğlu, A. (2021). LWT, 154, 112624.
This study aimed the utilization of fig stalk waste as an alternative pectin source. For this purpose, the characteristics of extracted stalk waste pectin (SP) were compared with those of citrus pectin (CP) and pectin extracted from defected substandard whole sun-dried figs (FP). The SP had a higher extraction yield (11.7%) than FP (9.4%). The galacturonic acid content and degree of esterification of SP (32.3 and 50.1%) were higher than those of FP (19.9 and 38.8%), but lower than those of CP (79.3 and 56.2%), respectively. The SP and CP had different sugar compositions (d-glucose, l-rhamnose, d-galactose and l-arabinose) and weight average molecular weights, but similar FTIR profiles. The SP showed almost 1.9 and 1.6-fold higher Trolox equivalent antioxidant capacity (TEAC), and 2.7 and 2.0-fold higher water absorption capacity than CP and FP, respectively. SP at 3% (w/w) showed the second highest viscosity after CP and the highest emulsion stability. Gels of SP and CP at 1.75–3% range had similar firmness, but SP formed more fracturable gels than CP. Sun-dried fig stalk waste is a better source of pectin than defected substandard whole sun-dried figs. The SP could be utilized to develop functional food with alternative textural and rheological properties.Hide Abstract
Ability of yeast metabolic activity to reduce sugars and stabilize betalains in red beet juice.
Dygas, D., Nowak, S., Olszewska, J., Szymańska, M., Mroczyńska-Florczak, M., Berłowska, J., Dziugan, P. & Kręgiel, D. (2021). Fermentation, 7(3), 105.
To lower the risk of obesity, diabetes, and other related diseases, the WHO recommends that consumers reduce their consumption of sugars. Here, we propose a microbiological method to reduce the sugar content in red beet juice, while incurring only slight losses in the betalain content and maintaining the correct proportion of the other beet juice components. Several yeast strains with different metabolic activities were investigated for their ability to reduce the sugar content in red beet juice, which resulted in a decrease in the extract level corresponding to sugar content from 49.7% to 58.2%. This strategy was found to have the additional advantage of increasing the chemical and microbial stability of the red beet juice. Only slight losses of betalain pigments were noted, to final concentrations of 5.11% w/v and 2.56% w/v for the red and yellow fractions, respectively.Hide Abstract
A new, quick, and simple protocol to evaluate microalgae polysaccharide composition.
Decamp, A., Michelo, O., Rabbat, C., Laroche, C., Grizeau, D., Pruvost, J. & Gonçalves, O. (2021). Marine Drugs, 19(2), 101.
In this work, a new methodological approach, relying on the high specificity of enzymes in a complex mixture, was developed to estimate the composition of bioactive polysaccharides produced by microalgae, directly in algal cultures. The objective was to set up a protocol to target oligomers commonly known to be associated with exopolysaccharides’ (EPS) nutraceutical and pharmaceutical activities (i.e., rhamnose, fucose, acidic sugars, etc.) without the constraints classically associated with chromatographic methods, while maintaining a resolution sufficiently high to enable their monitoring in the culture system. Determination of the monosaccharide content required the application of acid hydrolysis (2 M trifluoroacetic acid) followed by NaOH (2 M) neutralization. Quantification was then carried out directly on the fresh hydrolysate using enzyme kits corresponding to the main monosaccharides in a pre-determined composition of the polysaccharides under analysis. Initial results showed that the enzymes were not sensitive to the presence of TFA and NaOH, so the methodology could be carried out on fresh hydrolysate. The limits of quantification of the method were estimated as being in the order of the log of nanograms of monosaccharides per well, thus positioning it among the chromatographic methods in terms of analytical performance. A comparative analysis of the results obtained by the enzymatic method with a reference method (high-performance anion-exchange chromatography) confirmed good recovery rates, thus validating the closeness of the protocol. Finally, analyses of raw culture media were carried out and compared to the results obtained in miliQ water; no differences were observed. The new approach is a quick, functional analysis method allowing routine monitoring of the quality of bioactive polysaccharides in algal cultures grown in photobioreactors.Hide Abstract
Addition of pectin-alginate to a carbohydrate beverage does not maintain gastrointestinal barrier function during exercise in hot-humid conditions better than carbohydrate ingestion alone.
Flood, T. R., Montanari, S., Wicks, M., Blanchard, J., Sharpe, H., Taylor, L., Kuennen, M. R. & Lee, B. J. (2020). Applied Physiology, Nutrition, and Metabolism, 45(10).
The objective of this study was to compare the effects of consuming a 16% maltodextrin+fructose+pectin-alginate (MAL+FRU+PEC+ALG) drink against a nutrient-matched maltodextrin+fructose (MAL+FRU) drink on enterocyte damage and gastrointestinal permeability after cycling in hot and humid conditions. Fourteen recreational cyclists (7 men) completed 3 experimental trials in a randomized placebo-controlled design. Participants cycled for 90 min (45% maximal aerobic capacity) and completed a 15-min time-trial in hot (32°C) humid (70% relative humidity) conditions. Every 15 min, cyclists consumed 143 mL of either (i) water; (ii) MAL+FRU+PEC+ALG (90 g·h−1 CHO/16% w/v); or (iii) a ratio-matched MAL+FRU drink (90 g·h−1 CHO/16% w/v). Blood was sampled before and after exercise and gastrointestinal (GI) permeability, which was determined by serum measurements of intestinal fatty acid binding protein (I-FABP) and the percent ratio of lactulose (5 g) to rhamnose (2 g) recovered in postexercise urine. Compared with water, I-FABP decreased by 349 ± 67pg·mL−1 with MAL+FRU+PEC+ALG (p = 0.007) and by 427 ± 56 pg·mL−1 with MAL+FRU (p = 0.02). GI permeability was reduced in both the MAL+FRU+PEC+ALG (by 0.019 ± 0.01, p = 0.0003) and MAL+FRU (by 0.014 ± 0.01, p = 0.002) conditions relative to water. In conclusion, both CHO beverages attenuated GI barrier damage to a similar extent relative to water. No metabolic, cardiovascular, thermoregulatory, or performance differences were observed between the CHO beverages.Hide Abstract
Cross-linking of diluted alkali-soluble pectin from apple (Malus domestica fruit) in different acid-base conditions.
Gawkowska, D., Cieśla, J., Zdunek, A. & Cybulska, J. (2019). Food Hydrocolloids, 92, 285-292.
A diluted alkali-soluble pectin (DASP) fraction, extracted using sodium carbonate, is characterized by a low degree of methylesterification and has the ability to self-organize on mica. The aim of this study was to characterize the cross-linking process of this fraction, extracted from apples, over a wide pH range (3-11) and without the addition of salt. An FT-IR study showed an increase in the intensity of bands connected with νas and νs (COO−) and a decrease in the intensity of the band associated with ν (C=O) in the carboxyl group with increasing pH, which indicated the dissociation of the carboxyl groups of galacturonic acid units. An increase in the surface electrical charge of particles in the pH range of 3-7 confirmed this. The value of the average apparent dissociation constant (∼4.60) indicated the acidic character of the DASP fraction. An AFM study showed the morphological changes of the DASP fraction with increasing pH, which allowed for the evaluation of the cross-linking process. This fraction formed a network on mica at pH 4 and 9, while the aggregates were noted mainly at pH 11. For totally ionized carboxyl groups (pH 7), the pectin chains were separated from each other due to the electrostatic repulsion between them.Hide Abstract
Systemic Concocting of Cross‐Linked Enzyme Aggregates of Candida antarctica Lipase B (Novozyme 435) for the Biomanufacturing of Rhamnolipids.
Rathankumar, A. K., SaiLavanyaa, S., Saikia, K., Gururajan, A., Sivanesan, S., Gosselin, M., Vaidyanathan, V. K. & Cabana, H. (2019). Journal of Surfactants and Detergents, 22(3), 477-490.
In the present study, Candida antarctica lipase B was immobilized on amine‐functionalized silica microspheres as cross‐linked enzyme aggregates (CLEA) and utilized for the biomanufacturing of rhamnolipids (RL). Lipase CLEA synthesized under optimized conditions of 2.0:1.0 by volume of silica microsphere/enzyme concentration, a 1.0:2.5 (v/v) ratio of enzyme/2‐propanol, 7 mM glutaraldehyde concentration, when incubated at pH 9.0 and 40 °C, for a cross‐linking time of 30 min were observed to exhibit superior biocatalytic properties and a maximum enzyme load of 770 U g−1. Lipase CLEA exhibited enhanced pH stability in acidic and alkaline media and increased temperature resistance as compared to free lipase. Both free and CLEA lipases were used to synthesize RL in different solvent systems. After 12 h, from initiation of the esterification, the degree of esterification (molar conversion yield) reached 46% and 71% in the batch mode. 1H and 13C nuclear magnetic resonance (NMR) and high‐performance liquid chromatographic (HPLC) analysis confirm RL production by CLEA lipase. The CLEA showed greater confrontation to enzyme‐mediated bioprocess approach as compared to its soluble counterpart and exhibited excellent RL production and catalytic activity even after its tenth successive reuse.Hide Abstract
Interactions of anthocyanins with pectin and pectin fragments in model solutions.
Larsen, L. R., Buerschaper, J., Schieber, A. & Weber, F. (2019). Journal of Agricultural and Food Chemistry, 67(33), 9344-9353.
Anthocyanins determine the color and potential health-promoting properties of red fruit juices, but the juices contain remarkably less anthocyanins than the fruits, which is partly caused by the interactions of anthocyanins with the residues of cell wall polysaccharides like pectin. In this study, pectin was modified by ultrasound and enzyme treatments to residues of polysaccharides and oligosaccharides widely differing in their molecular weight. Modifications decreased viscosity and degrees of acetylation and methylation and released smooth and hairy region fragments. Native and modified pectin induced different effects on the concentrations of individual anthocyanins after short-term and long-term incubation caused by both hydrophobic and hydrophilic interactions. Results indicate that both pectin and anthocyanin structure influence these interactions. Linear polymers generated by ultrasound formed insoluble anthocyanin complexes, whereas oligosaccharides produced by enzymes formed soluble complexes with protective properties. The structure of the anthocyanin aglycone apparently influenced interactions more than the sugar moiety.Hide Abstract
Munoz-Munoz, J., Cartmell, A., Terrapon, N., Henrissat, B. & Gilbert, H. J. (2017). Proceedings of the National Academy of Sciences, 114(19), 4936-4941.
The human gut microbiota use complex carbohydrates as major nutrients. The requirement for an efficient glycan degrading systems exerts a major selection pressure on this microbial community. Thus, we propose that these bacteria represent a substantial resource for discovering novel carbohydrate active enzymes. To test this hypothesis, we focused on enzymes that hydrolyze rhamnosidic bonds, as cleavage of these linkages is chemically challenging and there is a paucity of information on L-rhamnosidases. Here we screened the activity of enzymes derived from the human gut microbiota bacterium Bacteroides thetaiotaomicron, which are up-regulated in response to rhamnose-containing glycans. We identified an α-L-rhamnosidase, BT3686, which is the founding member of a glycoside hydrolase (GH) family, GH145. In contrast to other rhamnosidases, BT3686 cleaved L-Rha-α1,4–D-GlcA linkages through a retaining double-displacement mechanism. The crystal structure of BT3686 showed that the enzyme displayed a type A seven-bladed β-propeller fold. Mutagenesis and crystallographic studies, including the structure of BT3686 in complex with the reaction product GlcA, revealed a location for the active site among β-propeller enzymes cited on the posterior surface of the rhamnosidase. In contrast to the vast majority of GH, the catalytic apparatus of BT3686 does not comprise a pair of carboxylic acid residues but, uniquely, a single histidine functions as the only discernable catalytic amino acid. Intriguingly, the histidine, His48, is not invariant in GH145; however, when engineered into structural homologs lacking the imidazole residue, α-L-rhamnosidase activity was established. The potential contribution of His48 to the catalytic activity of BT3686 is discussed.Hide Abstract
Zuhl, M., Dokladny, K., Mermier, C., Schneider, S., Salgado, R. & Moseley, P. (2015). Cell Stress and Chaperones, 20(1), 85-93.
Chronic glutamine supplementation reduces exercise-induced intestinal permeability and inhibits the NF-κB pro-inflammatory pathway in human peripheral blood mononuclear cells. These effects were correlated with activation of HSP70. The purpose of this paper is to test if an acute dose of oral glutamine prior to exercise reduces intestinal permeability along with activation of the heat shock response leading to inhibition of pro-inflammatory markers. Physically active subjects (N = 7) completed baseline and exercise intestinal permeability tests, determined by the percent ratio of urinary lactulose (5 g) to rhamnose (2 g). Exercise included two 60-min treadmill runs at 70 % of VO2max at 30°C after ingestion of glutamine (Gln) or placebo (Pla). Plasma levels of endotoxin and TNF-α, along with peripheral blood mononuclear cell (PBMC) protein expression of HSP70 and IκBα, were measured pre- and post-exercise and 2 and 4 h post-exercise. Permeability increased in the Pla trial compared to that at rest (0.06 ± 0.01 vs. 0.02 ± 0.018) and did not increase in the Gln trial. Plasma endotoxin was lower at the 4-h time point in the Gln vs. 4 h in the Pla (6.715 ± 0.046 pg/ml vs. 7.952 ± 1.11 pg/ml). TNF-α was lower 4 h post-exercise in the Gln vs. Pla (1.64 ± 0.09 pg/ml vs. 1.87 ± 0.12 pg/ml). PBMC expression of IkB TNF-α was higher 4 h post-exercise in the Gln vs. 4 h in the Pla (1.29 ± 0.43 vs. 0.8892 ± 0.040). HSP70 was higher pre-exercise and 2 h post-exercise in the Gln vs. Pla (1.35 ± 0.21 vs. 1.000 ± 0.000 and 1.65 ± 0.21 vs. 1.27 ± 0.40). Acute oral glutamine supplementation prevents an exercise-induced rise in intestinal permeability and suppresses NF-κB activation in peripheral blood mononuclear cells.Hide Abstract
Zuhl, M. N., Lanphere, K. R., Kravitz, L., Mermier, C. M., Schneider, S., Dokladny, K. & Moseley, P. L. (2014). Journal of Applied Physiology, 116(2), 183-191.
The objectives of this study are threefold: 1) to assess whether 7 days of oral glutamine (GLN) supplementation reduces exercise-induced intestinal permeability; 2) whether supplementation prevents the proinflammatory response; and 3) whether these changes are associated with upregulation of the heat shock response. On separate occasions, eight human subjects participated in baseline testing and in GLN and placebo (PLA) supplementation trials, followed by a 60-min treadmill run. Intestinal permeability was higher in the PLA trial compared with baseline and GLN trials (0.0604 ± 0.047 vs. 0.0218 ± 0.008 and 0.0272 ± 0.007, respectively; P < 0.05). IκBα expression in peripheral blood mononuclear cells was higher 240 min after exercise in the GLN trial compared with the PLA trial (1.411 ± 0.523 vs. 0.9839 ± 0.343, respectively; P < 0.05). In vitro using the intestinal epithelial cell line Caco-2, we measured effects of GLN supplementation (0, 4, and 6 mM) on heat-induced (37°C or 41.8°C) heat shock protein 70 (HSP70), heat shock factor-1 (HSF-1), and occludin expression. HSF-1 and HSP70 levels increased in 6 mM supplementation at 41°C compared with 0 mM at 41°C (1.785 ± 0.495 vs. 0.6681 ± 0.290, and 1.973 ± 0.325 vs. 1.133 ± 0.129, respectively; P < 0.05). Occludin levels increased after 4 mM supplementation at 41°C and 6 mM at 41°C compared with 0 mM at 41°C (1.236 ± 0.219 and 1.849 ± 0.564 vs. 0.7434 ± 0.027, respectively; P < 0.001). GLN supplementation prevented exercise-induced permeability, possibly through HSF-1 activation.Hide Abstract