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1.
Chem Pharm Bull (Tokyo) ; 70(1): 52-56, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34980734

RESUMEN

Lecithin reverse wormlike micelles (LRWs) have been studied recently for dermal application dosage use but the effects of the physicochemical properties of oils on the formation and rheological properties of LRWs have not been investigated. We studied the effect of oil on the formation of LRWs using 5 types of liquid paraffin (LP) with kinematic viscosities ranging from 4.00 to 88.0 mm2/s. Partial phase diagrams of lecithin/water/LP systems indicated that LPs with low molecular weights could form LRWs with only a small amount of water, but LPs with high molecular weights could not form LRWs, regardless of the water concentration. The solubility of lecithin in LPs was higher for low molecular weight LPs, thus possibly affecting the formation of LRWs. The zero-shear viscosity and relaxation time of LRWs initially increased with increasing water concentration, and then decreased. The water concentration providing the maximum value was dependent on the molecular weight of the LP, whereas the maximum amount and length of the LRWs were independent of the water concentration. Our results indicate that the molecular weight of LP affects the ease of formation and the viscoelasticity of LRWs.


Asunto(s)
Lecitinas/química , Parafina/química , Química Física , Micelas , Reología
2.
Food Chem ; 355: 129640, 2021 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-33799253

RESUMEN

The aim of this study was to develop methods for the determination of short- and medium-chain chlorinated paraffins (SCCPs; MCCPs) in vegetable oils and fish employing gas chromatography coupled with high-resolution mass spectrometry because of a lack of information on the presence of chlorinated paraffins in food consumed in Europe. For isolation of CPs from fish, an ethyl acetate extraction followed by a clean-up of the extract by gel permeation chromatography was performed. The same purification step was used for the isolation of CPs from the vegetable oils. The concentration range for SCCPs was <10-389 ng/g lipid weight (lw, mean 36 ng/g lw for the oils and 28 ng/g lw for the fish) and that for MCCPs was <20-543 ng/g lw (mean 55 ng/g lw for the oils and 59 ng/g lw for the fish). There was found a high variability in concentrations of CPs influenced by area of origin.


Asunto(s)
Peces , Análisis de los Alimentos/métodos , Cromatografía de Gases y Espectrometría de Masas , Halogenación , Parafina/análisis , Parafina/química , Aceites de Plantas/química , Animales , Monitoreo del Ambiente , Contaminación de Alimentos/análisis
3.
J Agric Food Chem ; 68(29): 7601-7608, 2020 Jul 22.
Artículo en Inglés | MEDLINE | ID: mdl-32530629

RESUMEN

Chlorinated paraffins (CPs) are organic pollutants that have caused widespread concerns in recent years. Because of their lipophilic characteristics, CPs may enter into the body through diet or other routes and exert adverse effects on human health. In this study, we investigated the occurrence and congener profiles of short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs) in 176 cooking oils and 19 oil containers collected from various markets in China. The concentrations of SCCPs and MCCPs in cooking oils were in the range of not detected (ND) to 16,055 ng/g and ND to 11,612 ng/g, respectively, and the geomean concentrations of MCCPs were lower than those of SCCPs. The concentrations of CPs in sesame oil, rapeseed oil, and camellia oil were higher than those in other types of oils, and different oil processing methods had different effects on the presence of CPs in the oils. CPs were detected in 5 out of 20 oil containers, although their concentrations were much lower than those detected in the oil samples, indicating that containers are not the main sources of CPs detected in the oils. The mean SCCP and MCCP intakes through cooking oils of the general Chinese population were 8.83 and 6.09 µg/kg/d, respectively.


Asunto(s)
Contaminación de Alimentos/análisis , Hidrocarburos Clorados/química , Parafina/química , Aceites de Plantas/química , China , Culinaria , Calor
4.
Int J Biol Macromol ; 161: 492-502, 2020 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-32534086

RESUMEN

The coating of fertilizers by polymers is one of the most efficient tools for their slow and control release into soil. This strategy avoids excessive use of the fertilizers and increases their availability to the crops needs. In the present paper, hydro-soluble diammonium phosphates (DAP) fertilizer was double coated following the dip-coating process by chitosan-clay composites as inner coating and paraffin wax as an outer coating. The chitosan composite preparation and characterization were deeply investigated. The montmorillonite (MMT) clay incorporation as filler improves the water barrier diffusion, mechanical properties, and thermal stability of the composite. The combination of the swelling behavior of the chitosan-clay composite (inner coating) and the hydrophobic property of paraffin wax (outer coating) was confirmed by the water holding capacity evaluation and the phosphorus release essays in water and soil. Indeed, the phosphorus dissolution from the coated DAP granules was significantly delayed compared to the uncoated DAP. Moreover, the biodegradation study of composite material in soil and the biochemical oxygen demand (BOD) tests revealed that the coating system proposed could be considered as a carbon source for microorganisms after the fertilization process, which confirms its sustainability.


Asunto(s)
Quitosano/química , Parafina/química , Fosfatos/química , Arcilla/química , Fertilizantes , Fósforo/química , Polímeros/química , Suelo/química , Agua/química
5.
Carbohydr Polym ; 229: 115525, 2020 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-31826510

RESUMEN

The extracellular polysaccharides produced by cyanobacteria have distinctive characteristics that make them promising for applications ranging from bioremediation to biomedicine. In this study, a sulfated polysaccharide produced by a marine cyanobacterial strain and named cyanoflan was characterized in terms of morphology, chemical composition, and rheological and emulsifying properties. Cyanoflan has a 71 % carbohydrate content, with 11 % of sulfated residues, while the protein account for 4 % of dry weight. The glycosidic-substitution analysis revealed a highly branched complex chemical structure with a large number of sugar residues. The cyanoflan high molecular mass fractions (above 1 MDa) and entangled structure is consistent with its high apparent viscosity in aqueous solutions and high emulsifying activity. It showed to be a typical non-Newtonian fluid with pseudoplastic behavior. Altogether, these results confirm that cyanoflan is a versatile carbohydrate polymer that can be used in different biotechnological applications, such as emulsifying/thickening agent in food or cosmetic industries.


Asunto(s)
Cianobacterias/metabolismo , Emulsionantes/química , Polisacáridos Bacterianos/química , Óxidos de Azufre/química , Peso Molecular , Parafina/química , Aceites de Plantas/química , Reología , Viscosidad
6.
J Food Sci ; 84(4): 832-841, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30912858

RESUMEN

The aim of the study was to control the release of peppermint oil (700 µL/L) by coating activated carbon (AC) contained in sachets with different solutions (tapioca starch, corn starch, gelatine, carnauba, paraffin, and mixed carnauba-paraffin) for inhibiting the growth of Aspergillus flavus on brown rice (BR). Paraffin-coated AC with adsorbed peppermint oil was then applied to extend the shelf life of BR during long-term storage (60 days) at 30 ± 2 °C. The mechanism of peppermint oil vapor release in this system was also studied using GC-MS. The result revealed that paraffin-coated AC with adsorbed peppermint oil present in sachets showed the highest antifungal activity against A. flavus growing on the surface of BR. In addition, paraffin-coated AC with adsorbed peppermint oil could prolong the shelf life of BR from 10 days (control) to at least 60 days under tropical climatic conditions. Moreover, storage of BR in the presence of sachets containing paraffin-coated AC with adsorbed peppermint oil at a concentration of 700 µL/L revealed no significant effects on major rice quality-related factors, such as moisture content, color, water uptake percentage, and gelatinization temperature. Peppermint oil component analysis by GC-MS indicated that paraffin could trap some minor components of peppermint oil and allow the major components such as menthone, menthol, and alpha-pinene, which are compounds that play an important role in mold growth inhibition, to be exposed to air. Thus, this research demonstrated the potential of paraffin-coated AC containing adsorbed peppermint oil for controlling the growth of molds during prolonged rice storage. PRACTICAL APPLICATION: Paraffin-coated activated carbon with adsorbed peppermint oil has the potential to be commercially applied to brown rice grains for facilitating long-term storage. This technique is beneficial for avoiding the occurrence of negative sensorial factors when peppermint oil vapors are used. This process is interesting and easy to apply during large-scale implementation of a rice storage system.


Asunto(s)
Aspergillus flavus/efectos de los fármacos , Conservantes de Alimentos/química , Oryza/microbiología , Parafina/química , Aceites de Plantas/química , Mentha piperita
7.
Biomed Microdevices ; 20(3): 68, 2018 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-30094581

RESUMEN

Temperature is a critical extrinsic physical parameter that determines cell fate. Hyperthermia therapy has become an efficient treatment for tumor ablation. To understand the response of tumor cells under thermal shocks, we present a paper-based photothermal array that can be conveniently coupled with commercial 96-well cell culture plates. This paper chip device was fabricated in one step using Parafilm® and Kimwipers® based on a heat lamination strategy. Liquid was completely adsorbed and confined within the cellulose fibres of hydrophilic regions. Then, Prussian blue nanoparticles (PB NPs) as the photothermal initiator were introduced into the loading wells, and thermal energy was generated via near infrared (NIR) laser irradiation. After assembling the paper device with a 96-well plate, the temperature of each well could be individually controlled by varying the loading amount of PB NPs and laser irradiation time. As a proof-of-concept study, the effects of local thermal shocks on HeLa cells were investigated using MTT cell viability assay and Live/Dead cell staining. The variation of cell viability could be monitored in situ with controllable temperature elevation. The proposed paper photothermal array loaded with thermal initiators represents an enabling tool for investigating the hyperthermia responses of biological cells. Moreover, the facile fabrication technique for paper patterning is advantageous for customizing high-throughput microfluidic paper-based analytical devices (µPADs) with extremely low cost.


Asunto(s)
Hipertermia Inducida , Parafina/química , Colorimetría , Ferrocianuros/química , Células HeLa , Humanos , Rayos Láser , Terapia por Luz de Baja Intensidad , Células MCF-7 , Nanopartículas/química , Neoplasias/terapia , Papel , Temperatura
8.
Food Res Int ; 111: 399-407, 2018 09.
Artículo en Inglés | MEDLINE | ID: mdl-30007702

RESUMEN

In this paper, the role of solvent characteristics on the rheological and physicochemical properties of organogels was investigated using different techniques. Vegetable oils, such as rice, sunflower and castor oil were used as solvents, for producing organogels with monoglycerides of fatty acids or a mixture of fatty alcohols (policosanol) as gelators. Moreover, two non-edible oils (silicon and paraffin oil) were also used for analysing the properties of solvents completely different in nature with respect to the edible ones, for a better interpretation of the given results. Organogels were investigated from a rheological point of view and through a microscopic analysis, given by polarised light (POM) and atomic force (AFM) microscopy, and X-rays to study the crystallinity of the system. The IR technique was used to analyse the intermolecular interactions, resulting in interesting information about the effect of oil polarity on the driving forces promoting structuration. This investigation showed that when solvents of a similar chemical nature are used, their physical properties, mainly oil polarity, are strictly related to the properties of the organogel, such as the onset of crystallisation temperature, the stiffness of the final material and its crystallinity. Anyway, these physical parameters seem insufficient to describe properly the role of solvents when oils of a different chemical nature are compared.


Asunto(s)
Aceite de Ricino/análisis , Aceite de Ricino/química , Aceite de Salvado de Arroz/análisis , Aceite de Salvado de Arroz/química , Aceite de Girasol/análisis , Aceite de Girasol/química , Geles , Peso Molecular , Aceites/análisis , Aceites/química , Parafina/análisis , Parafina/química , Reología , Espectroscopía Infrarroja por Transformada de Fourier
9.
J Chromatogr A ; 1534: 170-178, 2018 Jan 26.
Artículo en Inglés | MEDLINE | ID: mdl-29290397

RESUMEN

The main aim of this study was to detect and identify antibacterial components of fraction I derived from eleven commercial C. incanus herbal teas. Fraction I obtained by a well-established phytochemical protocol of a multi-step extraction was expected to contain flavonoid aglycons alone. Antibacterial profile of fraction I was demonstrated by means of thin-layer chromatography - direct bioautography (TLC-DB) using a Gram positive B. subtilis and a Gram negative A. fischeri strain. Six chromatographic zones of fraction I exhibited a well pronounced antibacterial potential. In qualitative terms, a good agreement was observed among chromatographic fingerprints and the corresponding bioautograms of the eleven samples. The compounds isolated from the six zones were analyzed by HPLC- diode array detector (DAD)-electrospray ionization (ESI)-MS. High numerical m/z values valid for certain constituents of these isolates suggested that some selected antibacterial components are, unexpectedly, flavonoid glycosides. In order to confirm this suggestion, three independent HPTLC methods (multi-development on amino phase and two two-dimensional developments on silica gel phase) were devised to in situ hydrolyze flavonoid glycosides and then separate and visualize the liberated glucose and some other building blocks of the zones' components. Additionally, the sensitivity of glucose detection with p-aminobenzoic acid reagent was enhanced by paraffin. In that way, the presence of the kaempferol glycosides (and not only the aglycones alone) in fraction I was confirmed. Beside kaempferol, p-coumaric acid as a building block unit was shown by HPLC-DAD-MS analysis of the hydrolyzed isolates. Results proved apigenin, kaempferide and acylated kaempferol glycosides (cis- and trans-tiliroside and their conjugates with p-coumaric acid) to be antibacterial components of fraction I. Because isomers of the coumaric acid conjugated tiliroside were detected only in fraction I and not in the crude C. incanus extract, they are regarded as artifacts produced through fractionation.


Asunto(s)
Antibacterianos/química , Cromatografía en Capa Delgada/métodos , Cistus/química , Fenoles/química , Ácido 4-Aminobenzoico/química , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Cistus/metabolismo , Flavonoides/química , Glucosa/análisis , Glucosa/química , Glicósidos/química , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Grampositivas/efectos de los fármacos , Hidrólisis , Parafina/química , Fenoles/aislamiento & purificación , Fenoles/farmacología , Extractos Vegetales/química , Dióxido de Silicio/química , Espectrometría de Masa por Ionización de Electrospray , Espectrofotometría Ultravioleta
10.
Chem Senses ; 42(7): 585-592, 2017 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-28821178

RESUMEN

Multiple lines of research have demonstrated that humans can perceive fat in the form of free fatty acids (FFAs). However, the dietary concentration of FFAs is generally very low and fat is mainly consumed as triacylglycerol (TAG). The aim of this study was to examine the perception of different fatty stimuli and possible associations between them. Therefore, detection thresholds for 4 fatty stimuli (oleic acid [FFA], paraffin oil [mixture of hydrocarbon molecules], canola oil [TAG-rich], and canola oil spiked with oleic acid [rich in TAGs and FFAs]) were determined in 30 healthy participants. Additionally, inter-individual differences in fat perception were examined. It was observed that oleic acid was perceivable at significantly lower concentrations than all other stimuli (P < 0.001). Similarly, canola oil with oleic acid was detectable at lower concentrations than canola oil alone (P < 0.001). Moreover, canola oil detection thresholds were significantly lower than paraffin oil detection thresholds (P = 0.017). Participants who were sensitive for low concentrations for oleic acid showed lower detection thresholds for canola oil with and without oleic acid, compared with participants that were less sensitive for oleic acid. The results of this study demonstrate that the higher the concentrations of FFAs in the stimuli, the lower the individual fat detection threshold. Moreover, participants being sensitive for lower concentrations of FFAs are also more likely to detect low concentrations of TAG-rich fats as it is found in the human diet.


Asunto(s)
Aceites/farmacología , Ácido Oléico/farmacología , Parafina/farmacología , Aceites de Plantas/farmacología , Umbral Gustativo/efectos de los fármacos , Gusto/efectos de los fármacos , Adolescente , Adulto , Ácidos Grasos no Esterificados/química , Ácidos Grasos no Esterificados/farmacología , Femenino , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Aceites/química , Ácido Oléico/química , Parafina/química , Aceites de Plantas/química , Aceite de Brassica napus , Triglicéridos/química , Triglicéridos/farmacología , Adulto Joven
11.
J Chromatogr A ; 1509: 123-131, 2017 Aug 04.
Artículo en Inglés | MEDLINE | ID: mdl-28647146

RESUMEN

Heavy petroleum fractions are produced during crude and synthetic crude oil refining processes and they need to be upgraded to useable products to increase their market value. Usually these fractions are upgraded to fuel products by hydrocracking, hydroisomerization and hydrogenation processes. These fractions are also upgraded to other high value commercial products like lubricant oils and waxes by distillation, hydrogenation, and oxidation and/or blending. Oxidation of hydrogenated heavy paraffinic fractions produces high value products that contain a variety of oxygenates and the characterization of these heavy oxygenates is very important for the control of oxidation processes. Traditionally titrimetric procedures are used to monitor oxygenate formation, however, these titrimetric procedures are tedious and lack selectivity toward specific oxygenate classes in complex matrices. Comprehensive two-dimensional gas chromatography (GC×GC) is a way of increasing peak capacity for the comprehensive analysis of complex samples. Other groups have used HT-GC×GC to extend the carbon number range attainable by GC×GC and have optimised HT-GC×GC parameters for the separation of aromatics, nitrogen-containing compounds as well as sulphur-containing compounds in heavy petroleum fractions. HT-GC×GC column combinations for the separation of oxygenates in oxidised heavy paraffinic fractions are optimised in this study. The advantages of the HT-GC×GC method in the monitoring of the oxidation reactions of heavy paraffinic fraction samples are illustrated.


Asunto(s)
Cromatografía de Gases/métodos , Parafina/química , Cromatografía de Gases/instrumentación , Calor , Hidrogenación , Compuestos de Nitrógeno/química , Oxidación-Reducción , Petróleo/análisis , Compuestos de Azufre/química
12.
J Econ Entomol ; 110(2): 507-516, 2017 04 01.
Artículo en Inglés | MEDLINE | ID: mdl-28073976

RESUMEN

In the northeastern United States, control of Lepidopteran pests of sweet corn, particularly corn earworm [Helicoverpa zea (Boddie)], is difficult using organic methods. The direct application of corn oil and Bacillus thuringiensis (Bt) to corn silk has been shown to reduce ear damage from corn earworm in past studies; these studies sought to optimize this method by evaluating additional carrier and biopesticide mixtures that comply with the United States Federal Insecticide, Fungicide, and Rodenticide Act and National Organic Standards. Carriers, which are liquids used to dissolve the biopesticide and deliver it into the tip of the ear, may have phytotoxic or insecticidal properties. Experiments conducted from 2001 to 2005 evaluated caterpillar damage and ear development effects from carriers (vegetable and paraffinic oils and carrageenan), biopesticides (Bt, spinsosad, and neem), and three emulsifiers in various combinations when applied directly to the tips of the ears 5-7 d after silk initiation. There were no effects of emulsifiers on ear quality, except for slight reduction in caterpillar damage in one of the two years. There were no differences among corn, soy, canola, and safflower oils in corn earworm control or tip development. The carrageenan carrier had the least effect upon ear development as measured by the length of nonpollinated kernels at the tip, compared to corn oil or paraffinic oil (JMS Stylet Oil), which caused the greatest tip damage as well as an oily discoloration. The carrier-pesticide combinations with the best ear quality overall were spinosad in carrageenan or corn oil, and Bt in carrageenan.


Asunto(s)
Protección de Cultivos/métodos , Insecticidas/química , Insecticidas/farmacología , Mariposas Nocturnas/efectos de los fármacos , Zea mays/crecimiento & desarrollo , Animales , Bacillus thuringiensis/genética , Carragenina/química , Carragenina/farmacología , Portadores de Fármacos , Combinación de Medicamentos , Emulsionantes/química , Emulsionantes/farmacología , Glicéridos/química , Glicéridos/farmacología , Control de Insectos/métodos , Macrólidos/farmacología , Massachusetts , Aceites/química , Aceites/farmacología , Parafina/química , Parafina/farmacología , Aceites de Plantas/química , Aceites de Plantas/farmacología , Plantas Modificadas Genéticamente , Terpenos/química , Terpenos/farmacología , Zea mays/efectos de los fármacos
13.
Skin Pharmacol Physiol ; 29(5): 250-256, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27632222

RESUMEN

Triterpenes of the outer bark of birch are known to improve wound healing. An oleogel with these triterpenes as active principle is approved by the European Medicines Agency. As foams can be applied without touching the skin, they might be an advantageous application form. A comparable wound-healing effect can be expected when the permeation flux of the triterpenes from different types of formulations, namely oleogels, water-in-oil emulsions and water-in-oil foams, is similar. The tested formulations were based on three lipids (medium-chain trigylcerides, sunflower oil and paraffin) which differ in their polarity and solvent power for the triterpenes. Infinite dose permeation experiments were performed using porcine skin which was injured by either tape stripping or skin grafting. The results showed that steady-state permeation flux and lag time depend clearly on the depth of the skin lesion. Moreover, it was substantially affected by the lipid used as basis for the different formulations. In contrast, the different formulation types showed a comparable permeation behaviour leading to the conclusion that all formulation types can be used alike for the treatment of wounds, and the results that have already been obtained with oleogels can be directly translated to the foam with its superior use properties.


Asunto(s)
Sistemas de Liberación de Medicamentos , Absorción Cutánea , Triterpenos/administración & dosificación , Triterpenos/farmacocinética , Animales , Emulsiones , Técnicas In Vitro , Compuestos Orgánicos , Parafina/química , Permeabilidad , Aceites de Plantas/química , Piel/lesiones , Piel/metabolismo , Aceite de Girasol , Porcinos , Triglicéridos/química , Triterpenos/química , Cicatrización de Heridas
14.
Genet Mol Res ; 15(2)2016 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-27323173

RESUMEN

An isolate capable of degrading paraffin wax was isolated from petroleum-contaminated sites in Daqing, China, and identified as Pseudomonas sp strain PW-1 by analyzing the 16S rDNA sequence (GenBank accession No.: KF529529) as well as the biochemical and physiological characteristics. The optimized degradation conditions of the isolate were as follows: FeSO4 metal ion concentration of 0.01 g, temperature of 30°C, (NH4)2SO4 nitrogen source concentration of 1.5 g/L, and a carbon: nitrogen ratio of 10:1. Response surface methodology-based analysis of the culture time, inoculation amount, and initial pH of the medium revealed that the optimal theoretical conditions were a culture time of 11.16 days, inoculation amount of 3.13%, and an initial pH of 9.29. The theoretical degradation rate was up to 54.68% under the optimal conditions. Taking into account the experimental conditions of a laboratory, 11.2 days of cultivating time, 3% inoculum, and a medium initial pH of 9.3 were used in practical settings. Experimental results showed that the degradation rate of paraffin wax was 52.85%, which demonstrated that this strain could degrade 1050 mg paraffin wax, using it as the sole carbon source, in a 1000-mL minimal salts medium. These results indicate that the strain PW1 can be used for application in oil wells with paraffin deposition problems in order to enhance oil recovery.


Asunto(s)
Biodegradación Ambiental , Parafina/química , Petróleo/metabolismo , Pseudomonas/metabolismo , Carbono/química , Carbono/metabolismo , China , Nitrógeno/química , Nitrógeno/metabolismo , Parafina/metabolismo , Petróleo/toxicidad , Filogenia , Pseudomonas/química , Pseudomonas/genética , ARN Ribosómico 16S/genética
15.
Chemosphere ; 138: 104-11, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26051978

RESUMEN

Short-chain chlorinated paraffins (SCCPs) are emerging persistent organic pollutants. It has been found that dietary intakes of SCCPs in China have recently increased and are now higher than in Japan and Korea. The contribution of cooking oil to dietary exposure to SCCPs in China was evaluated by analyzing SCCPs in cooking oil, raw seeds used to produce cooking oil, and fried confectionery products collected in China in 2010 and 2012. Detectable amounts of SCCP homologs were found in 48 out of the 49 cooking oil samples analyzed, and the SCCP concentrations varied widely, from <9 to 7500 ng g(-1). Estimated dietary intakes of total SCCPs in cooking oil ranged from <0.78 to 38 µg d(-1). The estimated dietary intake of SCCPs was relatively high (mean 14.8 µg d(-1)) for residents of Beijing. Fried confectionery was found to contain SCCP concentrations of 11-1000 ng g(-1). Cooking oil might therefore be one of the sources of SCCPs to Chinese diets. SCCPs were also detected in raw seeds used to produce cooking oil, but the concentrations varied widely. The SCCP homolog patterns in the raw seed and cooking oil samples were different, implying that the seeds used to produce the oil (and therefore the soil on which the seeds were produced) were unlikely to be the sources of SCCPs in cooking oil. Further investigations are needed to determine the routes through which cooking oil becomes contaminated with SCCPs during the production and processing of the oil.


Asunto(s)
Contaminantes Ambientales/análisis , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Hidrocarburos Clorados/análisis , Parafina/análisis , Aceites de Plantas/química , China , Culinaria , Contaminantes Ambientales/química , Hidrocarburos Clorados/química , Parafina/química , Semillas/química
16.
J Food Sci ; 80(5): C989-97, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25850679

RESUMEN

The objective of this research was to evaluate the physical properties of different types of wax/oil systems. Olive (OO), corn (CO), soybean (SBO), sunflower (SFO), safflower (SAFO), and canola (CAO) oils were mixed with sunflower oil wax (SFOW), paraffin wax (PW), and beeswax (BW) at different concentrations (1% to 10%). Results from this study show that the physical properties of wax/oil systems is affected not only by the concentration and type of wax used, but also by the type of oil used. In general, wax/oil systems formulated with SFOW generated crystalline networks with high enthalpies (1 to 22 J/g) and high G' values (2 to 6 × 10(6) Pa) compared with the values obtained for BW and PW. SFOW crystalline networks were characterized by needle-like crystals independently of the wax concentrations and type of oil used. BW crystalline networks, however, were characterized by different crystal morphologies (needle-like or spherulites) depending on the wax concentration and type of oil used. PW samples were characterized by a crystalline network formed by needle- and platelet-like crystals. Enthalpy values of BW and PW samples were similar (0.3 to 20 J/g), but BW samples resulted in significantly higher (P < 0.05) G' values in the 5% and 10% samples with values of 3.9 × 10(6) and 6.1 × 10(5) Pa for 10% BW and PW, respectively.


Asunto(s)
Grasas Insaturadas en la Dieta/análisis , Parafina/química , Aceites de Plantas/química , Ceras/química , Brassica/química , Carthamus/química , Cristalización , Ácidos Grasos Monoinsaturados/química , Helianthus/química , Humanos , Aceite de Brassica napus , Aceite de Cártamo/química , Aceite de Soja/química , Glycine max/química , Aceite de Girasol , Termodinámica
17.
Environ Sci Pollut Res Int ; 21(8): 5730-6, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24442963

RESUMEN

In this work, pigeon feathers, a kind of totally waste by-product from the poultry industry, were utilized to fabricate a highly porous keratin sponge in a very simple way by freeze-drying treatment of the dissolved keratin solution, and applied for the first time as an oil adsorbent. An improved method was proposed to dissolve the feather keratin using the inexpensive sodium disulfite as the reducing reagent for sulfitolysis reaction, with a much lower concentration of all involving reaction regents. Moreover, the regenerated keratin sponges obtained a high oil adsorption capacity of above 30 g/g for both liquid paraffin and soybean oil, as well as a good oil holding ability, suggesting that this keratin sponge might be a potential for use as oil adsorbent.


Asunto(s)
Restauración y Remediación Ambiental/métodos , Plumas/química , Queratinas/química , Parafina/química , Aceite de Soja/química , Adsorción , Crianza de Animales Domésticos , Animales , Residuos Industriales , Poríferos , Porosidad , Aves de Corral , Reciclaje , Eliminación de Residuos
18.
J Photochem Photobiol B ; 130: 93-101, 2014 Jan 05.
Artículo en Inglés | MEDLINE | ID: mdl-24300996

RESUMEN

Perinaphthenone (1H-phenalen-1-one, PN) is a reference photosensitizer producing singlet oxygen with a quantum yield close to one in a large variety of solvents. It is also the basic structure of a class of phototoxic phytoalexins. In this work, the PN photoreactivity was studied for the first time in a paraffinic wax, used as model of leaf epicuticular waxes. The PN photodegradation was monitored by UV-Vis spectroscopy. The triplet excited state, singlet oxygen and the hydroxyperinaphthenyl radical were detected by diffuse reflectance laser flash photolysis, near infrared phosphorescence and by EPR spectroscopy, respectively. The PN phototransformation was found to be fivefold faster in the wax than in n-heptane under steady-state irradiation. The hydroxyperinaphthenyl radical formation was observed in aerated irradiated paraffin wax while in n-heptane solution the radical was observed only in the absence of oxygen. These results show that under continuous irradiation, PN is much more easily phototransformed in a solid environment than in solution. Several photoproducts were identified, in particular phenalanone, PN dimers, and oxidized PN-alkanes adducts. Finally, when pyrethrum extract is added into the wax along with PN, the hydroxyperinaphthenyl radical concentration was increased by a factor of 2.4. Such photochemical reactions may occur when systemic pesticides enter the plant cuticle.


Asunto(s)
Fenalenos/química , Fenalenos/efectos de la radiación , Fármacos Fotosensibilizantes/química , Fármacos Fotosensibilizantes/efectos de la radiación , Oxígeno Singlete/química , Chrysanthemum cinerariifolium , Heptanos/química , Rayos Láser , Parafina/química , Plaguicidas/química , Fotólisis , Extractos Vegetales/química , Hojas de la Planta/química , Ceras/química
19.
J Chromatogr A ; 1294: 137-44, 2013 Jun 14.
Artículo en Inglés | MEDLINE | ID: mdl-23647609

RESUMEN

The Fischer-Tropsch (FT) process produces a variety of compounds over a wide carbon number range and the synthetic crude oil produced by this process is rich in highly valuable olefins and oxygenates, which crude oil only contains at trace levels. The characterization of these products is very challenging even when using comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOF-MS). The separation between cyclic paraffins and olefins is especially difficult since they elute in similar positions on the GC×GC chromatogram and since they have identical molecular masses with indistinguishable fragmentation patterns. Previously, a high performance liquid chromatography (HPLC) fractionation procedure was used prior to GC×GC-TOF-MS analysis to distinguish between alkenes and alkanes, both cyclic and non-cyclic, however, there was co-elution of the solvents used in the HPLC fractionation procedure, and the volatile components in the gasoline sample and the dilution introduced by the off-line fractionation procedure made it very difficult to investigate components present at very low concentrations. The hyphenation of supercritical fluid chromatography (SFC) to GC×GC is less complicated and the removal of the supercritical CO2 can be easily achieved without any loss of the volatile sample components, eliminating the introduction of co-eluting solvents as well as the dilution effect. This paper describes the on-line hyphenation of SFC to a GC×GC system in order to comprehensively characterize the chemical groups (saturates, unsaturates, oxygenates and aromatics) in an FT sample.


Asunto(s)
Alquenos/química , Cromatografía con Fluido Supercrítico/métodos , Cromatografía de Gases y Espectrometría de Masas/métodos , Parafina/química , Petróleo/análisis , Estructura Molecular
20.
Zhong Yao Cai ; 34(7): 1060-2, 2011 Jul.
Artículo en Chino | MEDLINE | ID: mdl-22066399

RESUMEN

OBJECTIVE: To study the chemical constituents of Pithecellobium clypearia. METHODS: Silica gel column chromatography and Sephadex LH-20 were used to separate and purify compounds from the EtOAc soluble fraction of Pithecellobium clypearia. 9 compounds were elucidated on the basis of physicochemical properties and spectrascopic analysis. RESULTS: They were identified as beta-Sitosterol (1), tritriacontane (2), 5-hydroxy-3,7,3',4'-tetramethoxyflavone (3), oleanolic acid (4), 5,4'-dihydroxy-3,7,3'-trimethoxyflavone (5), alpha-amyrin (6), luteolin (7), ursolic acid (8), luteoloside (9). CONCLUSION: Compounds 3 and 5 are isolated from this plant for the first time.


Asunto(s)
Fabaceae/química , Flavonoides/aislamiento & purificación , Plantas Medicinales/química , Flavonoides/química , Estructura Molecular , Ácido Oleanólico/química , Ácido Oleanólico/aislamiento & purificación , Parafina/química , Parafina/aislamiento & purificación , Hojas de la Planta/química , Tallos de la Planta/química
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