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1.
Food Sci Technol Int ; 30(3): 273-281, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-36650737

RESUMEN

Sugar-free food has been gaining popularity because of low-calorie content. But sugar replacement by high-intensity sweeteners can negatively affect sensory. In this study, the effect of the addition of sucralose (Suc), stevioside (Ste), and erythritol (Ery) as sugar substitutes on the sensory profile and overall acceptance of ice cream were evaluated by penalty analysis (PA) based on the check-all-that apply (CATA) method, with those of the partial least squares (PLS) regression. Twelve sweetening agents of ice cream samples were presented to 106 consumers who answered on an overall liking question using the 15-point hedonic scale and a CATA question with 32 attributes that described the sensory characteristics of ice cream. The results showed that mixed sweeteners (60%Suc+20%Ste+20%Ery or 60%Suc+10%Ste+30%Ery) can present an advantageous performance when used separately, and making ice cream similar to that of sucrose (Sac) added. Adding Suc, Ste, and Ery to ice cream hardly felt bitterness, astringency, and chemical-like sensations of the sweetening agent. The significant difference between different sweeteners is the intensity and speed of sweetness. Developing combination of high-potency sweeteners that can make sweetness appear quickly could open up new ways to design sugar-free ice cream.


Asunto(s)
Diterpenos de Tipo Kaurano , Glucósidos , Helados , Sacarosa/análogos & derivados , Edulcorantes , Eritritol/análisis , Helados/análisis , Gusto , Carbohidratos
2.
Artículo en Inglés | MEDLINE | ID: mdl-32629087

RESUMEN

Oral administration of sucralose has been reported to stimulate food intake through inducing hypothalamic neuropeptide Y (NPY) in mice and fruit flies. However, the underlying mechanisms of action of sucralose in hypothermia and NPY and monoamine regulation remain unknown. The aim of the present study was to investigate central effects of sucralose on body temperature, NPY, and monoamine regulation, as well as its peripheral effects, in chicks. In Experiment 1, 5-day-old chicks were centrally injected with 1 µmol of sucralose, other sweeteners (erythritol and glucose), or saline. In Experiment 2, chicks were centrally injected with 0.2, 0.4, and 1.6 µmol of sucralose or saline. In Experiment 3, chicks were centrally injected with 0.8 µmol of sucralose or saline, with a co-injection of 100 µg fusaric acid (FA), an inhibitor of dopamine-ß-hydroxylase, to examine the role dopamine in sucralose induced hypothermia. In Experiment 4, 7-16-day-old chicks were orally administered with 75, 150, and 300 mg/2 ml distilled water or sucralose, daily. We observed that the central injection of sucralose, but not other sweeteners, decreased body temperature (P < .05) in chicks; however, the oral injection did not influence body temperature, food intake, and body weight gain. Central sucralose administration decreased dopamine and serotonin and stimulated dopamine turnover rate in the hypothalamus significantly (P < .05). Notably, sucralose co-injection with FA impeded sucralose-induced hypothermia. Sucralose decreases body temperature potentially via central monoaminergic pathways in the hypothalamus.


Asunto(s)
Dopamina/análisis , Hipotálamo/metabolismo , Hipotermia/metabolismo , Serotonina/análisis , Sacarosa/análogos & derivados , Administración Oral , Animales , Temperatura Corporal , Encéfalo/metabolismo , Pollos , Eritritol/análisis , Ácido Fusárico/química , Glucosa/análisis , Infusiones Intraventriculares , Masculino , Neuropéptido Y/metabolismo , Sacarosa/química
3.
Int J Mol Sci ; 21(12)2020 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-32545883

RESUMEN

We present a case study report into nutritional competition between Trichoderma spp. isolated from wild raspberries and fungal phytopathogenic isolates (Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.), which infect soft fruit ecological plantations. The competition was evaluated on the basis of nutritional potentiates. Namely, these were consumption and growth, calculated on the basis of substrate utilization located on Biolog® Filamentous Fungi (FF) plates. The niche size, total niche overlap and Trichoderma spp. competitiveness indices along with the occurrence of a stressful metabolic situation towards substrates highlighted the unfolding step-by-step approach. Therefore, the Trichoderma spp. and pathogen niche characteristics were provided. As a result, the substrates in the presence of which Trichoderma spp. nutritionally outcompete pathogens were denoted. These were adonitol, D-arabitol, i-erythritol, glycerol, D-mannitol and D-sorbitol. These substrates may serve as additives in biopreparations of Trichoderma spp. dedicated to plantations contaminated by phytopathogens of the genera Colletotrichum sp., Botrytis sp., Verticillium sp. and Phytophthora sp.


Asunto(s)
Hongos Mitospóricos/fisiología , Phytophthora/crecimiento & desarrollo , Rubus/crecimiento & desarrollo , Trichoderma/fisiología , Botrytis/crecimiento & desarrollo , Colletotrichum/crecimiento & desarrollo , Eritritol/análisis , Frutas/crecimiento & desarrollo , Frutas/microbiología , Glicerol/análisis , Manitol/análisis , Ribitol/análisis , Rubus/microbiología , Saccharomycetales/crecimiento & desarrollo , Microbiología del Suelo , Sorbitol/análisis , Alcoholes del Azúcar/análisis
4.
Crit Rev Biotechnol ; 40(5): 608-622, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32299245

RESUMEN

Dietary habits that include an excess of added sugars have been strongly associated with an increased risk of obesity, heart disease, diabetes, and tooth decay. With this association in view, modern food systems aim to replace added sugars with low calorie sweeteners, such as polyols. Polyols are generally not carcinogenic and do not trigger a glycemic response. Furthermore, owing to the absence of the carbonyl group, they are more stable compared to monosaccharides and do not participate in Maillard reactions. As such, since polyols are stable at high temperatures, and they do not brown or caramelize when heated. Therefore, polyols are widely used in the diets of hypocaloric and diabetic patients, as well as other specific cases where controlled caloric intake is required. In recent years, erythritol and mannitol have gained increased importance, especially in the food and pharmaceutical industries. In these areas, research efforts have been made to improve the productivity and yield of the two polyols, relying on biotechnological manufacturing methods. The present review highlights the recent advances in the biotechnological production of erythritol and mannitol and summarizes the benefits of using the two polyols in the food and pharmaceutical industries.


Asunto(s)
Biotecnología/métodos , Eritritol/biosíntesis , Manitol/metabolismo , Bacterias/metabolismo , Industria Farmacéutica , Eritritol/análisis , Fermentación , Industria de Alimentos , Humanos , Manitol/análisis , Redes y Vías Metabólicas , Polímeros , Edulcorantes , Levaduras/metabolismo
5.
Shokuhin Eiseigaku Zasshi ; 59(3): 99-105, 2018.
Artículo en Japonés | MEDLINE | ID: mdl-30033995

RESUMEN

A quantitative determination method of erythritol, maltitol, lactitol and trehalose in foods by HPLC, and confirmation method by LC-MS/MS were developed. HPLC analysis was performed on a separation column packed with amino group-binding polymer with acetonitrile-water (80 : 20) as the mobile phase. The column was operated at room temperature, and the three sugar alcohols and trehalose were quantified. LC-MS/MS confirmation was performed on an amino group-bound column with acetonitrile-ammonium acetate solution as the mobile phase, with detection in the SRM mode. At low sample dilution ratios, the analysis may be affected by matrix derived from the sample, but this can be suppressed by 1,000-fold or greater dilution. Recoveries of the three sugar alcohols and trehalose spiked into food samples, such as tea, jelly, tablets (ramune candy), and chocolate, exceeded 90% (CV≦6.1%) in HPLC and 94% (CV≦4.8%) in LC-MS/MS.


Asunto(s)
Eritritol/análisis , Análisis de los Alimentos/métodos , Maltosa/análogos & derivados , Alcoholes del Azúcar/análisis , Trehalosa/análisis , Cromatografía Líquida de Alta Presión , Cromatografía Liquida , Maltosa/análisis , Espectrometría de Masas en Tándem
6.
Methods Enzymol ; 576: 225-49, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27480689

RESUMEN

The 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway occurs in the plastids of higher plants and in most economically important prokaryotes where it is responsible for the biosynthesis of the isoprenoid building blocks, isopentenyl diphosphate and dimethylallyl diphosphate. These five-carbon compounds are the substrates for the enormous variety of terpenoid products, including many essential metabolites and substances of commercial value. Increased knowledge of the regulation of the MEP pathway is critical to understanding many aspects of plant and microbial metabolism as well as in developing biotechnological platforms for producing these commercially valuable isoprenoids. To achieve this goal, researchers must have the ability to investigate the in vivo kinetics of the pathway by accurately measuring the concentrations of MEP pathway metabolites. However, the low levels of these metabolites complicate their accurate determination without suitable internal standards. This chapter describes a sensitive method to accurately determine the concentrations of MEP pathway metabolites occurring at trace amounts in biological samples using liquid chromatography coupled to triple quadrupole mass spectrometry. In addition, simple protocols are given for producing stable isotope-labeled internal standards for these analyses.


Asunto(s)
Arabidopsis/metabolismo , Cromatografía Liquida/métodos , Eritritol/análogos & derivados , Escherichia coli/metabolismo , Espectrometría de Masas/métodos , Fosfatos de Azúcar/metabolismo , Arabidopsis/química , Eritritol/análisis , Eritritol/metabolismo , Escherichia coli/química , Marcaje Isotópico/métodos , Redes y Vías Metabólicas , Fosfatos de Azúcar/análisis
7.
Braz. j. microbiol ; 47(2): 417-423, Apr.-June 2016. tab, graf
Artículo en Inglés | LILACS | ID: lil-780825

RESUMEN

Abstract Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300 g L-1), erythritol production increased by 15% compared to the culture without the surfactant where it reached 142 g L-1 after 5 days, which corresponded to 0.47 g g-1 yield and productivity of 1.1 g L-1 h-1. Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.


Asunto(s)
Tensoactivos/metabolismo , Medios de Cultivo/metabolismo , Yarrowia/metabolismo , Eritritol/biosíntesis , Manitol/metabolismo , Polisorbatos/análisis , Polisorbatos/metabolismo , Tensoactivos/análisis , Octoxinol/análisis , Octoxinol/metabolismo , Medios de Cultivo/química , Eritritol/análisis , Manitol/análisis
8.
Braz J Microbiol ; 47(2): 417-23, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26991292

RESUMEN

Various chemical compounds, including surfactants, when introduced to culture media may increase the permeability of cellular membranes and thereby affect the quantity of metabolites excreted by cells. The aim of the present study was to evaluate the impact of detergents including Triton X-100, Span 20 and Tween 80 on erythritol production from glycerol by Yarrowia lipolytica Wratislavia K1 in a shake-flask experiment, batch and fed-batch cultures. When Span 20 was added to a fed-batch culture with glycerol as a carbon source (300gL(-1)), erythritol production increased by 15% compared to the culture without the surfactant where it reached 142gL(-1) after 5 days, which corresponded to 0.47gg(-1) yield and productivity of 1.1gL(-1)h(-1). Therefore, it was concluded that Span 20 considerably enhanced the production of this polyol from glycerol.


Asunto(s)
Medios de Cultivo/metabolismo , Eritritol/biosíntesis , Manitol/metabolismo , Tensoactivos/metabolismo , Yarrowia/metabolismo , Medios de Cultivo/química , Eritritol/análisis , Manitol/análisis , Octoxinol/análisis , Octoxinol/metabolismo , Polisorbatos/análisis , Polisorbatos/metabolismo , Tensoactivos/análisis
9.
Environ Sci Process Impacts ; 16(6): 1413-21, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24777436

RESUMEN

This work presents the application of a new method to facilitate the distinction between biologically produced (primary) and atmospherically produced (secondary) organic compounds in ambient aerosols based on their chirality. The compounds chosen for this analysis were the stereomers of 2-methyltetraols, (2R,3S)- and (2S,3R)-methylerythritol, (l- and d-form, respectively), and (2S,3S)- and (2R,3R)-methylthreitol (l- and d-form), shown previously to display some enantiomeric excesses in atmospheric aerosols, thus to have at least a partial biological origin. In this work PM10 aerosol fractions were collected in a remote tropical rainforest environment near Manaus, Brazil, between June 2008 and June 2009 and analysed. Both 2-methylerythritol and 2-methylthreitol displayed a net excess of one enantiomer (either the l- or the d-form) in 60 to 72% of these samples. These net enantiomeric excesses corresponded to compounds entirely biological but accounted for only about 5% of the total 2-methyltetrol mass in all the samples. Further analysis showed that, in addition, a large mass of the racemic fractions (equal mixtures of d- and l-forms) was also biological. Estimating the contribution of secondary reactions from the isomeric ratios measured in the samples (=ratios 2-methylthreitol over 2-methylerythritol), the mass fraction of secondary methyltetrols in these samples was estimated to a maximum of 31% and their primary fraction to a minimum of 69%. Such large primary fractions could have been expected in PM10 aerosols, largely influenced by biological emissions, and would now need to be investigated in finer aerosols. This work demonstrates the effectiveness of chiral and isomeric analyses as the first direct tool to assess the primary and secondary fractions of organic aerosols.


Asunto(s)
Aerosoles/análisis , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Eritritol/análogos & derivados , Atmósfera/química , Brasil , Eritritol/análisis
10.
J AOAC Int ; 96(5): 1048-53, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-24282945

RESUMEN

A discrimination method based on polyalcohol determination was developed for authenticity of protected geographical indication (PGI) vinegars-Shanxi extra aged vinegar (SVs) in China. Six polyalcohols in vinegars including erythritol, arabitol, xylitol, inositol, mannitol, and sorbitol were selected as the PGI discriminators. GC/MS was used to analyze the polyalcohols in the SVs, Zhenjiang vinegars (ZVs), Kazuo aged vinegars (KVs), and other non-geographical indication protected vinegars (NVs). SVs can be distinguished from KVs by the chemical markers mannitol and sorbitol, although the production processes for both types of vinegars are similar. Principal component analysis (PCA) was used to distinguish SVs from ZVs and NVs. The differences among the three kinds of vinegars shown by PCA results may be due to the higher erythritol content in SVs, and the inositol and mannitol in ZVs. This study also found that the amount of polyalcohols in Chinese vinegars increases with the acidity value only, regardless of the aging time. The overall results indicated that the polyalcohols can be practicable discriminators for SV discrimination.


Asunto(s)
Ácido Acético/análisis , Alcoholes del Azúcar/análisis , Eritritol/análisis , Inositol/análisis , Manitol/análisis , Sorbitol/análisis , Xilitol/análisis
11.
Fungal Genet Biol ; 56: 42-53, 2013 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-23644150

RESUMEN

Light induces various responses in fungi including formation of asexual and sexual reproductive structures. The formation of conidia in the filamentous fungus Aspergillus nidulans is regulated by red and blue light receptors. Expression of conidia associated con genes, which are widely spread in the fungal kingdom, increases upon exposure to light. We have characterized the light-inducible conF and conJ genes of A. nidulans which are homologs of con-6 and con-10 of Neurospora crassa. con genes are expressed during conidia formation in asexual development. Five minutes light exposure are sufficient to induce conF or conJ expression in vegetative mycelia. Similar to N. crassa there were no significant phenotypes of single con mutations. A double conF and conJ deletion resulted in significantly increased cellular amounts of glycerol or erythritol. This leads to a delayed germination phenotype combined with increased resistance against desiccation. These defects were rescued by complementation of the double mutant strain with either conF or conJ. This suggests that fungal con genes exhibit redundant functions in controlling conidia germination and adjusting cellular levels of substances which protect conidia against dryness.


Asunto(s)
Aspergillus nidulans/crecimiento & desarrollo , Aspergillus nidulans/genética , Proteínas Fúngicas/genética , Regulación Fúngica de la Expresión Génica/efectos de la radiación , Luz , Esporas Fúngicas/crecimiento & desarrollo , Estrés Fisiológico , Secuencia de Aminoácidos , Aspergillus nidulans/efectos de la radiación , Citosol/química , Eritritol/análisis , Perfilación de la Expresión Génica , Técnicas de Inactivación de Genes , Prueba de Complementación Genética , Glicerol/análisis , Datos de Secuencia Molecular , Micelio/efectos de la radiación , Alineación de Secuencia
12.
J Food Sci ; 78(5): S777-84, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23574577

RESUMEN

The effect of sucrose replacement by erythritol and inulin was studied in short-dough cookies using instrumental and sensory analysis. Two levels of replacement were used (25% and 50% of total sucrose content). Descriptive sensory analysis showed that the sucrose replacement affects visual and texture cookies characteristics, being the differences perceived by mouth greater than by hand. In general, sucrose substitutes produced a less crispy cookie and lower consumer acceptability, with the exception of 25% sucrose replacement by inulin. Matrix aeration attributes such as open and crumbly obtained by trained panel were important properties, and correlated positively with consumer acceptance and negatively with maximum force at break (hardness). Inulin cookies sensory properties were more similar to the control than the erythritol cookies. Also, consumer overall acceptance decreased significantly with sucrose replacement by erythritol. The analysis of texture and sound revealed that inulin cookies were softer whereas erythritol cookies were harder in comparison with control cookies; despite this difference, inulin cookies had similar sound characteristics to erythritol cookies.


Asunto(s)
Eritritol/análisis , Inulina/análisis , Sacarosa/análisis , Comportamiento del Consumidor , Eritritol/química , Manipulación de Alimentos , Humanos , Inulina/química , Odorantes , Sacarosa/química , Gusto
13.
Se Pu ; 30(8): 843-6, 2012 Aug.
Artículo en Chino | MEDLINE | ID: mdl-23256390

RESUMEN

A high performance liquid chromatographic (HPLC) method has been developed for the simultaneous determination of meso-erythritol and L-erythrulose in fermentation broth. The chromatographic conditions were as follows: Lichrospher 5-NH2 column (250 mm x 4.6 mm) with the temperature of 30 degrees C, acetonitrile-water (90: 10, v/v) as mobile phase with the flow rate of 1.0 mL/min. meso-Erythritol was detected by refractive index (RI) detector at 35 degrees C and L-erythrulose was detected by ultraviolet (UV) detector at 277 nm at room temperature. The linear range for meso-erythritol was 1.00 - 100.00 g/L with a correlation coefficient of 0.998 5. The limit of detection (LOD) and the limit of quantification (LOQ) for meso-erythritol were 0.10 g/L and 0.45 g/L, respectively. The linear range for L-erythrulose was 1.00 - 100.00 g/L with a correlation coefficient of 0.995 8. The LOD and LOQ for L-erythrulose were 0.50 g/L and 0.87 g/L, respectively. The relative standard deviations (RSDs) of intraday and interday for meso-erythritol were less than 3.28% and 5.30%, respectively. The intraday and interday RSDs for L-erythrulose were less than 2.16% and 2.25%, respectively. The recoveries of meso-erythritol and L-erythrulose in fermentation broth were greater than 99%. The samples from fermentation broth were detected at different time points. The measurement by the novel HPLC method was not affected by the other components in the fermentation broth. Furthermore, the HPLC method can be used for the determination of the substrate meso-erythritol and the product L-erythrulose simultaneously.


Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Eritritol/análisis , Fermentación , Tetrosas/análisis , Tetrosas/biosíntesis
14.
J Food Sci ; 77(9): S323-8, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22908895

RESUMEN

UNLABELLED: The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener with various functional properties, compared to other sweeteners (sucrose, sucralose, erythritol, rebaudioside A), over a wide range of sweetness commonly found in foods and beverages (3% to 20% sucrose [w/v]). A total of 34 subjects evaluated aqueous solutions of the 5 sweeteners for the perceived intensities of sweetness, bitterness, astringency, chemical-like sensations, and sweet aftertaste, using the general version of the Labeled Magnitude Scale. The relationship between the physical concentrations of the sweeteners and their perceived sweetness (that is, psychophysical functions) was derived to quantify the relative sweetness and potency of the sweeteners. The results suggest that tagatose elicits a sweet taste without undesirable qualities (bitterness, astringency, chemical-like sensations). Out of the 5 sweeteners tested, rebaudioside A was the only sweetener with notable bitterness and chemical-like sensations, which became progressively intense with increasing concentration (P < 0.001). In terms of perceived sweetness intensity, the bulk sweeteners (tagatose, erythritol, sucrose) had similar sweetness growth rates (slopes > 1), whereas the high-potency sweeteners (sucralose, rebaudioside A) yielded much flatter sweetness functions (slopes < 1). Because the sweetness of tagatose and sucrose grew at near-identical rates (slope = 1.41 and 1.40, respectively), tagatose produced about the same relative sweetness to sucrose across the concentrations tested. However, the relative sweetness of other sweeteners to sucrose was highly concentration dependent. Consequently, sweetness potencies of other sweeteners varied across the concentrations tested, ranging from 0.50 to 0.78 for erythritol, 220 to 1900 for sucralose, and 300 to 440 for rebaudioside A, while tagatose was estimated to be approximately 0.90 times as potent as sucrose irrespective of concentration. PRACTICAL APPLICATION: The present study investigated the sensory characteristics and relative sweetness of tagatose, an emerging natural low-calorie sweetener, compared to other sweeteners. Study results suggest that tagatose elicits a sweet taste without undesirable qualities over a wide range of concentrations. Tagatose produced about the same relative sweetness to sucrose across the concentrations tested, while the relative sweetness of other sweeteners was highly concentration dependent. The present data provide a general guideline when considering the use of tagatose and other sweeteners in foods and beverages.


Asunto(s)
Hexosas/análisis , Edulcorantes/análisis , Gusto , Adolescente , Adulto , Bebidas/análisis , Diterpenos de Tipo Kaurano/análisis , Eritritol/análisis , Femenino , Humanos , Modelos Lineales , Masculino , Sacarosa/análogos & derivados , Sacarosa/análisis , Percepción del Gusto , Adulto Joven
15.
J Chromatogr A ; 1218(51): 9288-94, 2011 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-22104215

RESUMEN

In order to facilitate the determination of the primary and secondary origin of atmospheric organic aerosols, a novel method involving chiral capillary gas chromatography coupled with mass spectrometry has been developed and validated. The method was focused on the analysis of 2-methylerythritol and 2-methylthreitol, considered to be tracers of secondary organic aerosols from the oxidation of atmospheric isoprene. The method was validated by performing various tests using authentic standards, including pure enantiomeric standards. The result showed that the analytical method itself does not affect the enantiomeric composition of the samples analyzed. The method was applied on atmospheric aerosols from a boreal forest collected in Aspvreten, Sweden and on laboratory samples obtained from liquid phase oxidation of isoprene and smog chamber experiments. Aerosol samples contained one enantiomer of 2-methylerythritol in significantly larger quantities than the others. In contrast, the liquid-phase oxidation of isoprene and its gas-phase oxidation in the smog chamber produced all enantiomers in equal quantities. The results obtained where the enantiomer fraction, EF, is larger than 0.50 suggest that 2-methyltetrols in atmospheric aerosols may also have biological origin. Information about the differences between enantiomer fractions obtained using this method brings new insights in the area of atmospheric aerosols.


Asunto(s)
Contaminantes Atmosféricos/análisis , Atmósfera/química , Eritritol/análogos & derivados , Cromatografía de Gases y Espectrometría de Masas/métodos , Aerosoles/análisis , Butadienos/análisis , Butadienos/química , Eritritol/análisis , Eritritol/química , Hemiterpenos/análisis , Hemiterpenos/química , Límite de Detección , Oxidación-Reducción , Pentanos/análisis , Pentanos/química , Reproducibilidad de los Resultados , Estereoisomerismo , Suecia , Árboles
16.
Plant Cell Environ ; 34(8): 1241-7, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21443577

RESUMEN

The methylerythritol 4-phosphate (MEP) and the mevalonate pathways are the unique synthesis routes for the precursors of all isoprenoids. An original mean to measure the carbon flux through the MEP pathway in plants is proposed by using cadmium as a total short-term inhibitor of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate (MEcDP) reductase (GcpE) and measuring the accumulation rate of its substrate MEcDP by (31) P-NMR spectroscopy. The MEP pathway metabolic flux was determined in spinach (Spinacia oleracea), pea (Pisum sativum), Oregon grape (Mahonia aquifolium) and boxwood (Buxus sempervirens) leaves. In spinach, flux values were compared with the synthesis rate of major isoprenoids. The flux increases with light intensity (fourfold in the 200-1200 µmol m(-2) s(-1) PPFR range) and temperature (sevenfold in the 25-37 °C range). The relationship with the light and the temperature dependency of isoprenoid production downstream of the MEP pathway is discussed.


Asunto(s)
Ciclo del Carbono , Eritritol/análogos & derivados , Plantas/metabolismo , Terpenos/metabolismo , Buxus/metabolismo , Cadmio/farmacología , Inhibidores Enzimáticos/farmacología , Eritritol/análisis , Eritritol/metabolismo , Luz , Espectroscopía de Resonancia Magnética , Mahonia/metabolismo , Redes y Vías Metabólicas , Ácido Mevalónico/metabolismo , Oxidorreductasas/antagonistas & inhibidores , Oxidorreductasas/metabolismo , Pisum sativum/metabolismo , Radioisótopos de Fósforo , Spinacia oleracea/metabolismo , Temperatura
17.
Anal Bioanal Chem ; 391(2): 609-15, 2008 May.
Artículo en Inglés | MEDLINE | ID: mdl-18369603

RESUMEN

Sugar alcohols are widely used as food additives and drug excipients. Erythritol (INS 968) is an important four-carbon sugar alcohol in the food industry. Erythritol occurs naturally in certain fruits, vegetables, and fermented foods. Currently, HPLC and GC methods are in use for the quantification of erythritol in natural/processed foods. However, an immunoassay for erythritol has not been developed so far. We have utilized affinity-purified erythritol-specific antibodies generated earlier [9] to develop an indirect competitive ELISA. With erythritol-BSA conjugate (54 mol/mol; 100 ng/well) as the coating antigen, a calibration curve was prepared using known amounts of standard meso-erythritol (0.1-100,000 ng) in the immunoassay. Watermelon (Citrullus lanatus) and red wine were selected as the food sources containing meso-erythritol. The amount of meso-erythritol was calculated as 2.36 mg/100 g fresh weight of watermelon and 206.7 mg/L of red wine. The results obtained from the immunoassay are in close agreement with the reported values analyzed by HPLC and GC (22-24 mg/kg in watermelon and 130-300 mg/L in red wine). The recovery analyses showed that added amounts of meso-erythritol were recovered fairly accurately with recoveries of 86-105% (watermelon) and 85-93.3% (red wine). The method described here for erythritol is the first report of an immunoassay for a sugar alcohol.


Asunto(s)
Ensayo de Inmunoadsorción Enzimática/métodos , Eritritol/análisis , Eritritol/inmunología , Análisis de los Alimentos/métodos , Cromatografía de Gases , Cromatografía Líquida de Alta Presión/métodos , Cromatografía por Intercambio Iónico/métodos , Citrullus/química , Aditivos Alimentarios/análisis , Vino/análisis
18.
Carbohydr Res ; 343(5): 893-902, 2008 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-18299126

RESUMEN

We developed a method for the direct identification and quantification of carbohydrates in raw vegetable extracts using (13)C NMR spectroscopy without any preliminary step of precipitation or reduction of the components. This method has been validated (accuracy, precision and response linearity) using pure compounds and artificial mixtures before being applied to authentic ethanolic extracts of pine needles, pine wood and pine cones and fir twigs. We determined that carbohydrates represented from 15% to 35% of the crude extracts in which pinitol was the principal constituent accompanied by arabinitol, mannitol, glucose and fructose.


Asunto(s)
Carbohidratos/análisis , Espectroscopía de Resonancia Magnética/métodos , Extractos Vegetales/química , Tracheophyta/química , Abies/química , Carbohidratos/química , Eritritol/análisis , Eritritol/química , Etanol/química , Fructosa/análisis , Fructosa/química , Glucosa/análisis , Glucosa/química , Inositol/análogos & derivados , Inositol/análisis , Inositol/química , Manitol/análisis , Manitol/química , Estructura Molecular , Monosacáridos/análisis , Monosacáridos/química , Pinus/química , Alcoholes del Azúcar/análisis , Alcoholes del Azúcar/química
19.
Environ Sci Technol ; 40(22): 6934-7, 2006 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-17153997

RESUMEN

PM2.5 samples were collected from June to December 2005 in Potsdam, New York and analyzed for polar organic compounds by GC/MS. The major compounds that were identified in the samples included 2-methyltetrols (2-methylthreitol and 2-methylerythritol), levoglucosan, cispinonic acid, and mannitol. 2-Methyltetrols were quantified during the analysis. A seasonal variation for these two diastereoisomers was observed, with the highest concentrations occurring during the summer and the lowest concentrations occurring during the winter. OC/EC analyses of these samples were also performed. The variation of the carbon contribution of 2-methyltetrols to OC was found to follow the same pattern as the concentration variation of 2-methyltetrols. During summer, the period of high photochemical activity, the maximum carbon contribution of 2-methyltetrols to OC was 2.8%. The observation of high 2-methyltetrol concentrations during the summer indicates isoprene is a significant summertime source of secondary organic aerosol in this rural area in the northeastern United States.


Asunto(s)
Contaminantes Atmosféricos/análisis , Compuestos Orgánicos/análisis , Estaciones del Año , Butadienos , Carbono/análisis , Monitoreo del Ambiente , Eritritol/análisis , Cromatografía de Gases y Espectrometría de Masas , Hemiterpenos , New York , Pentanos , Alcoholes del Azúcar/análisis
20.
Rapid Commun Mass Spectrom ; 20(14): 2104-8, 2006.
Artículo en Inglés | MEDLINE | ID: mdl-16767687

RESUMEN

Recently, it has been proposed (M. Claeys et al., Science 2004; 303: 1173) that the atmospheric OH-radical-mediated photooxidation of isoprene is a source of two major secondary organic aerosol (SOA) components, that is, 2-methylthreitol and 2-methylerythritol. These diastereoisomeric tetrols, which were characterized for the first time in the fine size fraction (<2.5 microm aerodynamic diameter) of aerosols collected in the Amazon rain forest during the wet season, were proposed to enhance the capability of the aerosols to act as cloud-condensation nuclei. In the present study, we performed the oxidation of isoprene in aqueous solution under conditions that attempted to mimic atmospheric OH-radical-induced photooxidization, and monitored and characterized on-line the reaction products via electrospray ionization mass (and tandem mass) spectrometry in the negative ion mode. The results show that the reaction of isoprene with photo- or chemically generated hydroxyl radicals indeed yields 2-methyltetrols. Other polyols were also detected, and they may therefore be considered as plausible SOA components eventually formed in normal or more extreme OH-radical-mediated photooxidation of biogenic isoprene.


Asunto(s)
Contaminantes Atmosféricos/química , Butadienos/química , Monitoreo del Ambiente/métodos , Hemiterpenos/química , Radical Hidroxilo/química , Pentanos/química , Polímeros/análisis , Espectrometría de Masa por Ionización de Electrospray/métodos , Aerosoles/química , Contaminantes Atmosféricos/efectos de la radiación , Atmósfera/química , Butadienos/efectos de la radiación , Eritritol/análisis , Hemiterpenos/efectos de la radiación , Radical Hidroxilo/efectos de la radiación , Oxidación-Reducción , Tamaño de la Partícula , Pentanos/efectos de la radiación , Fotoquímica , Estereoisomerismo , Alcoholes del Azúcar/análisis
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