Presence Of Xylitol Research Articles

Combined eutexia and amorphization for simultaneous enhancement of dissolution rate of triamterene and hydrochlorothiazide: Preparation of orodispersible tablets

ABSTRACT Background: Triamterene is an oral antihypertensive drug with dissolution-limited poor bioavailability. It can be used as monotherapy or in fixed dose combination with hydrochlorothiazide which also suffers from poor dissolution. Moreover, co-processing of drugs in fixed dose combination can alter their properties. Accordingly, pre-formulation studies should investigate the effect of co-processing and optimize the dissolution of drugs before and after fixed dose combination. This is expected to avoid deleterious interaction (if any) and to hasten the biopharmaceutical properties. Objective: Accordingly, the aim of this work was to optimize the dissolution rate of triamterene alone and after fixed dose combination with hydrochlorothiazide. Methodology: Triamterene was subjected to dry co-grinding with xylitol, HPMC-E5 or their combination. The effect of co-grinding with hydrochlorothiazide was also tested in absence and presence of xylitol and HPMC-E5. The products were assessed using Fourier-transform infrared (FTIR), differential scanning calorimetry, X-ray powder diffraction (XRPD), in addition to dissolution studies. Optimum formulations were fabricated as oral disintegrating tablets (ODT). Results: Co-processing of triamterene with xylitol formed eutectic system which hastened dissolution rate. HPMC-E5 resulted in partial amorphization and improved triamterene dissolution. Co-grinding with both materials combined their effects. Co-processing of triamterene with hydrochlorothiazide resulted in eutexia but the product was slowly dissolving due to aggregation. This problem was vanished in presence of HPMC-E5 and xylitol. Compression of the optimum formulation into ODT underwent fast disintegration and liberated acceptable amounts of both drugs. Conclusion: The study introduced simple co-processing with traditional excipients for development of ODT of triamterene and hydrochlorothiazide.

Antimicrobial activity of probiotic Streptococcus salivarius LAB813 on in vitro cariogenic biofilms

ObjectiveTo investigate the antimicrobial activity of a novel commensal strain of Streptococcus salivarius, LAB813, against Streptococcus mutans biofilms. MethodsThe inhibitory activity of LAB813 towards S. mutans was tested using mono-, dual-, and multi-species cariogenic biofilms formed on three types of orthodontic appliances (metal, ceramic, aligner). The activity of the commercially available probiotic, BLIS M18™ was used as control. ResultsLAB813 significantly inhibited S. mutans biofilms with cell killing approximating 99% for all materials. LAB813 showed effectiveness at inhibiting S. mutans in more complex multi-species biofilms with cell killing approximating 90% for all three materials. When comparing the killing kinetics of the probiotics, LAB813 had a faster rate of killing biofilms than M18. Experiments conducted with cell-free culture supernatant confirmed the presence of an inhibitory substance of proteinaceous nature. The addition of xylitol, a common sugar substitute used for human consumption, potentiated the inhibitory effects of LAB813 against S. mutans embedded in a more complex fungal-bacterial biofilm. ConclusionsLAB813 possesses strong antimicrobial activity, potent anti-biofilm properties, and enhanced antimicrobial activity in the presence of xylitol. The identification and characterization of strain LAB813 exhibiting antimicrobial activity towards S. mutans hold exciting promise for this novel strain to be developed as an oral probiotic for use in the prevention of dental caries.

Molecular details of ovalbumin solvation by an aqueous solution of xylitol in different pH environment:Ultrasonic and molecular simulation studies

Artificial sweetener-protein interactions are playing a major role in enhancing the functional properties of protein-based food and pharmaceutical products. This article discusses the molecular details of ovalbumin (OA) solvation in an aqueous solution of xylitol (XY) in different pH environments. This task can be accomplished by both Ultrasonic and Molecular Simulation studies. In ultrasonic studies, density, ultrasound velocity, viscosity, and surface tension have been measured for OA in various pH of phosphate buffer with and without XY. Further, some of the calculated parameters such as adiabatic compressibility, intermolecular free length, free volume, etc have been worked out. From ultrasonic results, pH dependent preferential hydration of OA was noticed in the presence of XY in an aqueous environment. In Molecular Dynamics Simulation (MDS) studies, water and XY accumulation to OA surface for different pH models were analyzed. The different states of protonation of the OA surface promote two distinct effects on the solvent and cosolvent orientation.

Polyols Induce the Production of Antifungal Compounds by Lactobacillus plantarum.

Mycotoxins may be present in nuts, coffee, cereals, and grapes, among other products. Increasing concerns about human health and environmental protection have driven the application of biological control techniques that can inhibit fungal contaminants. In this study, the growth inhibition of the ochratoxigenic fungus Aspergillus carbonarius Ac 162 was evaluated using 5 lactic acid bacteria (LAB). The LAB studied were Lactobacillus plantarum MZ801739 (J), Lactobacillus plantarum MZ809351 (31) and Lactobacillus plantarum MZ809350 (34), isolated in the Ivory Coast, and Lactobacillus plantarum MN982928 (3) and Leuconostoc citreum MZ801735 (23), isolated in Mexico. J, 31, 34, 3 and 23 are the internal strain codes from our laboratory. LAB were cultivated in De Man, Rogosa and Sharpe (MRS) broth, and different polyols (glycerol, mannitol, sorbitol, and xylitol) were added to the culture broth to stimulate the production of antifungal compounds. The fungal inhibition studies were performed using the poisoned food technique. The highest inhibition of A. carbonarius growth was obtained by cultivating L. plantarum MZ809351 in the presence of xylitol and glycerol. Under these conditions, 1 L of the L. plantarum MZ809351 cultures were used to identify antifungal compounds. The compounds were concentrated by solid-phase extraction and then characterized by GC-MS. In addition to 9-octadecenoic acid, 3 diketopiperazines or cyclic dipeptides were identified, including cyclo (Leu-Leu), cyclo (Pro-Gly) and cyclo (Val-Phe), which were compounds related to microbial antifungal activities. Xylitol and glycerol induced the production of these antifungal compounds against A. carbonarius Ac 162. On the other hand, adding xylitol and glycerol to the MRS broth reduced the Ochratoxin A (OTA) content to 56.8 and 54.7%, respectively. This study shows the potential for using L. plantarum MZ809351 as a biocontrol agent to prevent the growth of A. carbonarius and reduce the production of OTA in foods.

Effect of xylitol on the growth of Lactobacillus acidophilus for food and pharmaceutical applications / Efeito do xilitol no crescimento do Lactobacillus acidophilus em alimentos e aplicações farmacêuticas

The aim of this study was to compare the effect of different concentrations of xylitol on the Lactobacillus acidophilus (LA) growth from different origins: LA from a pharmaceutical supplement produced by Aché ® (LA1), LA lyophilized used in dairy fermented products produced by Sacco ® (LA2) and LA of manipulated pharmaceutical supplements of a local pharmacy of Cascavel-Paraná/Brazil (LA3). All of them were recommended to help the regulation of human intestinal flora. In MRS broth amounts of xylitol were added until final concentrations reached 3%, 8%, 12%, 15%, 18%, 25% and 40%. After sterilizing the medium, the standardized inoculum was added with subsequent incubation at 72 h in anaerobiosis. It was possible to conclude that xylitol influences the growth of LA and the higher concentrations of xylitol the lower growth of LA. LA3 growth 2x above than the other origins until 18% xylitol. This may favor the use of this strain for pharmaceutical preparations using xylitol. LA2 presented some advantages in relation to the pharmaceutical origin, since its growth in the presence of xylitol was faster, and this could indicate a possible greater amount of microorganisms in the intestinal tract in a short time. Over 12% were observed an inhibitory effect, by reducing the LA count below the recommended limit of 10 9 . This result is important, because as xylitol has the same sweetness potency of sucrose, it is believed that it may be used in different formulations until 12%, concentration commonly used as sweetener without significantly influencing the growth of Lactobacillus acidophilus .

EFFECT OF POLYATOMIC ALCOHOLS ON CHROME CURRENT OUTPUT AT ELECTROCHEMICAL WASTE WATER PURIFICATION

Waste water is generated in almost all industrial enterprises and is contaminated with various organic and inorganic impurities and some heavy metals to varying degrees. The aim of this study is to study the effect of polyhydric alcohols on the current efficiency in the electrochemical method of purification of industrial wastewater contaminated with various heavy metals, in particular chromate ions. The current efficiency of chromium does not exceed 18% during the electrolysis of wastewate, during the process in the presence of xylitol in an amount of 0,16%, the current efficiency increased by 21,9%, in the presence of glycerin in an amount of 0,18%, the current efficiency increased by 23,1%, in the presence of ethylene glycol in the amount of 0,20%, the current efficiency increased by 24,2%

Effectiveness of xylitol and alginate containing toothpaste in patients with chronic generalized periodontitis and type II diabetes suffering from xerostomia

Relevance. Dental disease management in type II diabetic patients suffering from xerostomia and an effective selection of oral care products moisturizing the mucus membrane have been a crucial problem for a long time. Typical for xerostomia symptoms such as dry mouth, burning tongue, pain during swallowing and eating solid food disorder interfere with choosing effective hygiene measures. The selection of a proper toothpaste that can help in effectively maintaining moisture environment in the mouth, and create comfort in the oral cavity plays a significant role.The aim of the study was to evaluate the clinical efficacy of a toothpaste containing xylitol and alginate (R.О.С.S.) in patients with generalized chronic periodontitis (GCP) and type II diabetes, suffering from xerostomia. Materials and methods. 40 patients, (mean age 58 ± 5.1 years, min = 52.5, max = 64) with moderate GCP and type II diabetes, suffering from xerostomia were studied. All patients underwent questioning, dental examination, periodontal status scoring, salivary flow rate assessment and saliva pH test. Patients were randomly divided into two groups: experiment and control. Monitoring was carried out for 3 months. All patients received professional tooth cleaning, after which the experimental group was instructed to use a toothpaste containing xylitol and alginate during three months, while the control groups was instructed to keep using their own toothpaste. Patients were reexamined after 3 months. Results. The experimental group which used the xylitol and alginate toothpaste demonstrated improvement in all parameters: periodontal status, salivary flow rate and saliva pH in comparison with the control group. No irritating effect on the sensitive mucous membrane was recorded. Conclusion. The presence of xylitol, alginate and a natural plant component (chamomile extract) in the toothpaste seem to provide notable anti-inflammatory and moisturizing effects. The tested toothpaste contains no antiseptics, fragrances or detergents. The absence of irritating effect on the sensitive mucous membrane allows its use without limiting the duration of use.

Corrigendum: Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside.

[This corrects the article DOI: 10.3389/fchem.2018.00111.].

Enhanced synergistic effects of xylitol and isothiazolones for inhibition of initial biofilm formation by Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538.

Bacterial biofilms, formed on biotic or abiotic surfaces, can lead to serious environmental or medical problems. Therefore, it is necessary to find novel antimicrobial agents to combat biofilms, or more effective combinations of existing biocides. In this study, initial biofilms of Pseudomonas aeruginosa ATCC 9027 and Staphylococcus aureus ATCC 6538 in the presence of xylitol or xylitol and isothiazolones were determined using crystal violet staining in 96-well microplates and confocal laser scanning microscopy. Xylitol and isothiazolones exhibited enhanced synergistic inhibition of initial biofilm formation, and also the structure and production of extracellular polymeric substances by P. aeruginosa ATCC 9027 and S. aureus ATCC 6538 in a dose-dependent manner. In addition, xylitol and isothiazolones inhibited and restored the swimming motility of P. aeruginosa ATCC 9027, respectively. These findings show that a combination of xylitol and isothiazolones exerts pronounced antimicrobial activity against P. aeruginosa and S. aureus biofilms and may be applicable for preventing or reducing bacterial biofilms in vitro.

Viscoelastic and Functional Properties of Cod-Bone Gelatin in the Presence of Xylitol and Stevioside.

The physical, rheological, structural and functional properties of cod bone gelatin (CBG) with various concentrations (0, 2, 4, 6, 10, and 15%) of low-calorie sweeteners [xylitol (X) and stevioside (S)] to form gels were investigated. The gel strength of CBGX increased with increased xylitol due presumably to hydrogen bonds between xylitol and gelatin, but with CBGS the highest gel strength occurred when S concentration was 4%. Viscosity of CBGS samples were higher than CBGX due to S's high molecular mass. The viscoelasticity (G′ and G′′), foaming capacity and fat binding capacity of CBGX were higher while foam stability was lower. The emulsion activity and emulsion stability of CBGX were a little lower than CBGS at the same concentration. The structure of X is linear making it easier to form a dense three-dimensional network structure, while the complex cyclic structure of S had more difficulty forming a network structure with cod bone gelatin. Therefore, X may be a better choice for sweetening gelatin gels.

Surface reactivity of octacalcium phosphate-derived fluoride-containing apatite in the presence of polyols and fluoride.

The present study was designed to characterize co-precipitated fluoridated apatitic materials from octacalcium phosphate (OCP) precursor and to investigate their surface reactions with polyols including glycerol in the presence of fluoride ions. Laboratory-synthesized fluoridated apatite crystals (LS-FA) were obtained in a solution containing fluoride (F) from 25 to 500 ppm. LS-FAs and commercially available fluoroapatite (FA) and hydroxyapatite (HA) were characterized by physical techniques, such as X-ray diffraction. LS-FA obtained in the presence of 100 ppmF (100 ppm-LS-FA) had an apatitic structure, but its solubility was close to HA in a culture medium (α-MEM) despite the fact it contains over 3 wt % of F. 100 ppm-LS-FA, FA, and HA were then subjected to the human serum albumin (HSA) adsorption test at pH 7.4 (in a 150 mM Tris-HCl buffer) and the dissolution and re-mineralization experiments in the presence of xylitol, D-sorbitol, or glycerol, and F under acidic and neutral conditions. Adsorption affinity of HSA was estimated as highest for FA and lowest for LS-FA. LS-FA, FA, and HA were immersed in a lactic acid solution with the polyols and/or F ion-containing solution up to 200 ppm to analyze the dissolution behavior. LS-FA had the highest dissolution tendency in the conditions examined. Glycerol enhanced the dissolution of phosphate from apatite crystals in particular from LS-FA. The results suggest that the apatite crystals, obtained through the hydrolysis of OCP in the presence of F, provide a more reactive surface than FA or HA under physiological environments. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 2235-2244, 2018.

3,6-Anhydro-l-galactose, a rare sugar from agar, a new anticariogenic sugar to replace xylitol.

The significance for anticariogenic sugar substitutes is growing due to increasing demands for dietary sugars and rising concerns of dental caries. Xylitol is widely used as an anticariogenic sugar substitute, but the inhibitory effects of xylitol on Streptococcus mutans, the main cause of tooth decay, are exhibited only at high concentrations. Here, the inhibitory effects of 3,6-anhydro-l-galactose (AHG), a rare sugar from red macroalgae, were evaluated on S. mutans, in comparison with those of xylitol. In the presence of 5g/l of AHG, the growth of S. mutans was retarded. At 10g/l of AHG, the growth and acid production by S. mutans were completely inhibited. However, in the presence of xylitol, at a much higher concentration (i.e., 40g/l), the growth of S. mutans still occurred. These results suggest that AHG can be used as a new anticariogenic sugar substitute for preventing dental caries.

Antifungal Activity of Lactobacillus sp. Bacteria in the Presence of Xylitol and Galactosyl-Xylitol.

Lactic acid fermentation is a natural method of antimicrobial food protection. Antagonistic activity of Lactobacillus sp. bacteria, taking part in this process, is directed mainly against the same or other microorganisms. In this work we determine the impact of the presence of xylitol and galactosyl-xylitol on the antagonistic activity of 60 Lactobacillus sp. strains against indicator molds (Alternaria alternata, Alternaria brassicicola, Aspergillus niger, Fusarium latenicum, Geotrichum candidum, and Mucor hiemalis) and yeasts (Candida vini). We used double-layer method to select antifungal strains of Lactobacillus bacteria and poisoned medium method to confirm their fungistatic properties. Additionally, we examined the inhibition of Alternaria brassicicola by Lactobacillus paracasei ŁOCK 0921 cultivated with xylitol or galactosyl-xylitol directly on wild cherries. The presence of xylitol and its galactosyl derivative led to increase of spectrum of antifungal activity in most of the studied plant-associated lactobacilli strains. However, no single strain exhibited activity against all the indicator microorganisms. The antifungal activity of Lactobacillus bacteria against molds varied considerably and depended on both the indicator strain and the composition of the medium. The presence of xylitol and galactosyl-xylitol in the growth medium is correlated with the antifungal activity of the studied Lactobacillus sp. bacteria against selected indicator molds.

Assessment on Rheological and Texture Properties of Xylitol‐Substituted Dadih

AbstractDadih is a dairy‐based dessert made of milk, water, sugar and agar, which is popular especially among South East Asian people. It has sweet taste due to high sugar content in its formulation. An excessive intake of sugar is harmful to human health, and it would be beneficial if the conventional sugar is replaced by a sugar substitute. In order to formulate a healthier dadih, xylitol was used to replace sucrose in three different levels of compositions (0, 50 and 100%), which xylitol provides intense sweetness with fewer calories. Therefore, the objective of this study was to evaluate the effect of xylitol substitution on rheological and textural properties of xylitol‐substituted dadih. Process parameters were cooking temperatures (85–95C) and cooking times (10–20 min). It was found that cooking temperature had the biggest impact on dadih. All samples showed gel‐like behavior where the value of G′ (storage modulus) was higher than G″ (loss modulus). Samples that were prepared under high temperatures illustrated higher value of G′ with elastic gel property regardless of the xylitol composition. Sample prepared at 95C cooking temperature, 20‐min cooking time and 0% xylitol exhibited the highest value of hardness and internal gel strength with 0.892 N ± 0.002 and 0.248 N ± 0.006, respectively. In general, the presence of xylitol in dadih contributed to its softer texture compared to a product that is made from sucrose. However, xylitol‐substituted dadih prepared at 85C with longer cooking time (15 to 20 min) met the required texture as conventional dadih.Practical ApplicationsXylitol is currently one of most popular sugar replacement due to its abundance compensation to consumers' health. Thus, the study on the effect of xylitol substitution on different types of food can benefit the future of food industry. This research focused on finding the optimal xylitol substitution under different process conditions in dadih production. The rheological and texture analysis on samples with various process conditions and xylitol substitution confirmed that the physical properties of dadih are easily affected by these two factors. Physical properties of dadih have an important role in consumer's acceptability; hence, rheology and texture analysis are crucial to determine the physical properties of xylitol‐substituted dadih.

Growth of boehmite particles in the presence of xylitol: morphology oriented by the nest effect of hydrogen bonding

The ability to design nanoparticles size and shape through the addition of simple and commercially available organic molecules is of particular interest in the catalytic domain because huge amounts of very fine powders are needed. The origin of this effect is all the more difficult to elucidate because the involved interactions are weak. In this paper, we have investigated the shaping of boehmite AlO(OH) nanoparticles in the presence of polyols like xylitol (C(5) alditol) by a combined experimental and theoretical approach. Experimental techniques such as XRD, TEM, IEP measurements, adsorption isotherms measurements, and (13)C MAS NMR experiments demonstrate that the effect of xylitol has a thermodynamic origin and suggest weak interactions between xylitol and the surface. Furthermore, the strongest proportion of lateral faces ((100), (001), and (101)) that of basal face would be in agreement with a preferential adsorption upon lateral surfaces. These results were refined by a computational approach. DFT calculations of surface energies (taking into account temperature and solvation effects) and of NMR shielding constants corroborate that molecular adsorption mode is preferred over all adsorption modes involving exchanges with surface OH groups. The preferred adsorption on lateral surfaces is attributed to the nest effect induced by hydroxyl groups localized on the concavities of the (001) and (101) surfaces, able to stabilize the xylitol molecule by hydrogen-bonding, whereas the basal (010) surface is almost flat. This combined experimental and computational approach thus provides interesting rationalization for the morphology effects observed.

Difference in the xylitol sensitivity of acid production among Streptococcus mutans strains and the biochemical mechanism

Xylitol inhibits the glycolysis and growth of Streptococcus mutans, but to different degrees among strains. Thus, we studied the biochemical mechanism through which the inhibition varies, using S. mutans strains ATCC 31989, NCTN 10449, and NCIB 11723, which are highly sensitive, moderately sensitive, and resistant to xylitol, respectively, under strictly anaerobic conditions such as those found in deep layers of dental plaque. Xylitol (30 mM) decreased the rate of acid production from glucose (10 mM) in ATCC 31989, NCTC 10449, and NCIB 11723 by 86, 26, and 0%, respectively. The activities of the xylitol : phosphoenolpyruvate phosphotransferase system (PEP-PTS) relative to those of glucose : PEP-PTS were 120, 16, and 3%, respectively. In ATCC 31989 and NCTC 10449, intracellular accumulation of xylitol 5-phosphate and decreases of fructose 1,6-bisphosphate and glucose 6-phosphate were observed. Furthermore, in the presence of xylitol (30 mM), glucose : PEP-PTS activities decreased by 34, 17, and 0%, respectively. These findings indicated that the higher the xylitol : PEP-PTS activity was and the more effectively xylitol decreased glucose : PEP-PTS activity, the more sensitive the strain was to xylitol. These results suggest that the following inhibitory mechanisms are active in the xylitol-sensitive mutans streptococci: direct inhibition of glycolytic enzymes by xylitol 5-phosphate derived from xylitol : PEP-PTS and, possibly, indirect inhibition through competition for the phosphoryl donor, HPr-P, between glucose and xylitol : PEP-PTSs.

Differential expression profiles of Streptococcus mutans ftf, gtf and vicR genes in the presence of dietary carbohydrates at early and late exponential growth phases

Dental caries is one of the most common infectious diseases that affects humans. Streptococcus mutans, the main pathogenic bacterium associated with dental caries, produces a number of extracellular sucrose-metabolizing enzymes, such as glucosyltransferases (GTFB, GTFC and GTFD) and fructosyltransferase (FTF). The cooperative action of these enzymes is essential for sucrose-dependent cellular adhesion and biofilm formation. A global response regulator (vicR) plays important roles in S. mutans ftf and gtf expression in response to a variety of stimuli. A real-time reverse-transcription polymerase chain-reaction was used to quantify the relative levels of ftf, gtfB, gtfC, gtfD and vicR transcription of S. mutans in the presence of various dietary carbohydrates: sucrose, d-glucose, d-fructose, d-glucitol (d-sorbitol), d-mannitol and xylitol. Ftf was highly expressed at late exponential phase in the presence of sorbitol and mannitol. GtfB was highly expressed in the presence of all the above carbohydrates except for xylitol at early exponential growth phase and glucose and fructose at late exponential growth phase. Similar to gtfB, the expression of gtfC was also induced with the presence of all the tested carbohydrates except for xylitol at early growth and glucose and fructose at late exponential phase. In addition, no effect of mannitol on gtfC expression at early exponential phase was observed. GtfD was less influenced compared to the gtfB and gtfC, demonstrating enhanced expression especially in the presence of sorbitol, glucose, mannitol and xylitol at early exponential phase and mannitol at late exponential phase. VicR expression was induced only at the presence of xylitol at late exponential phase, and a decrease in expression was recorded at early exponential phase. Our findings show that dietary carbohydrates have a major influence on the transcription of ftf, gtfB, gtfC and gtfD, but less on vicR. Sorbitol and mannitol, which are considered as noncariogenic sugar substitutes, may indirectly affect caries by promoting biofilm formation via enhanced expression of gtfs and ftf. These results suggest regulatory circuits for exopolysaccharide gene expression in S. mutans.

Antagonistic activity of lactic acid bacteria as probiotics against selected bacteria of the Enterobaceriacae family in the presence of polyols and their galactosyl derivatives.

Probiotic lactic acid bacteria were grown on erythritol, xylitol, sorbitol or lactitol and produced various derivatives: gal-erythritol, gal-xylitol, and gal-sorbitol as prebiotics. Galactosyl derivatives of erythritol, xylitol and sorbitol were metabolised by Lactobacillus spp. This resulted in their antagonistic activity against the test microflora. No activity was observed in the presence of xylitol and erythritol. Gal-sorbitol obtained by enzymatic transglycosylation from lactose had the same abilities of inducing the antagonistic activity of lactic acid bacteria that lactitol had.

Xylitol Inhibition of Acid Production and Growth of Mutans Streptococci in the Presence of Various Dietary Sugars under Strictly Anaerobic Conditions

The aim of this study was to investigate the inhibitory effect of xylitol on the growth of and acid production by mutans streptococci in the presence of various dietary sugars, and the relationship between the inhibition and the accumulation of xylitol 5-phosphate (X5P) under strictly anaerobic conditions like those in the deep layers of dental plaque. Xylitol retarded the growth of mutans streptococci in the presence of glucose (G), galactose (Gal), maltose (M), lactose (L) or sucrose (S) as an energy source, though the inhibition of growth on fructose (Fr) was small. Xylitol inhibited acid production by washed cells of Streptococcus mutans from G, Gal, M, L or S (12–83% inhibition). S. mutans accumulated X5P intracellularly through activity of the phosphoenolpyruvate-xylitol phosphotransferase system (PEP-xylitol PTS) when they fermented these sugars in the presence of xylitol. However, in the presence of Fr, no inhibition of acid production was observed. In addition, the amounts of X5P during the fermentation of Fr were smaller than those of other sugars in spite of the presence of PEP-xylitol PTS activity. These results suggest that along with the intracellular accumulation of X5P, xylitol decreases the growth and acid production of mutans streptococci in the presence of various dietary sugars except Fr.

Determination of sugars and alditols in food samples by HPAEC with integrated pulsed amperometric detection using alkaline eluents containing barium or strontium ions

The addition, in mobile phase, of alkaline-earth divalent cations such as Sr(II) and Ba(II) is shown to be a versatile means of improving the separation of alditols and carbohydrates, which are conventionally determined by high-performance anion-exchange chromatography (HPAEC) coupled with integrated pulsed amperometry using gold working electrodes. It is believed that Ba(II) or Sr(II) ions are effective both in forming solution complexes with sugar analytes, and ensuring thoroughly carbonate-free alkaline mobile phase flowing through the column. As a result, substantial benefits can be obtained in terms of peak shape, attainable column efficiency, and detection sensitivity. This work describes determination of alditols ( myo-inositol, d-sorbitol, and d-mannitol), and carbohydrates (glucose, fructose, and sucrose) in some common fruits and fruit products (apricot, plum, watermelon, lemon, mandarin, grape, and dietetic cherry jam) and vegetable foodstuffs (cauliflower, cucumber, fennel, tomato, turnip, and celery). The free sugar contents in fruit juices were determined directly, without pretreatment or derivatization, following a sample extraction. While myo-inositol was found in many fruits, fruit products and vegetables examined, no presence of xylitol was detected.