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At least 163 records · Page 9Linked to original sources

PubMed2000

Comparison of oil recovered from tea tree leaf by ethanol extraction and steam distillation.

Two methods for the determination of oil and oil major components from tea tree (Melaleuca alternifolia) leaf are quantitatively compared. A microwave assisted ethanol extraction and a 2-h hydrodistillation technique were used on both dry and fresh leaf from a low and a high oil concentration tree. There was no significant difference between dry and fresh leaf. The distillation technique recovered 88% and 82% of the extractable oil for the low and high concentration material, respectively. For both samples this distilled oil was composed of lower absolute amounts of sesquiterpenoids and marginally lower amounts of monoterpenoids. Extending the distillation to 6 h increased the sesquiterpenoid recovery but this resulted in a reduction in both the absolute and relative amounts of the oxygenated monoterpenoids, terpinen-4-ol and 1,8-cineole.

Chromatography, Gas↗

PubMed2003

Chemical and sensorial aroma characterization of freshly distilled Calvados. 2. Identification of volatile compounds and key odorants.

Eight samples of freshly distilled Calvados were extracted using pentane. Gas chromatography with either a mass spectrometer or flame ionization detector was used to determine the volatile compounds composition of the extracts. More than 120 molecules were identified in Calvados and then correlated with results obtained by olfactometric analysis in our earlier work [Guichard, H.; Lemesle, S.; Ledauphin, J.; Barillier, D.; Picoche, B. Chemical and Sensorial Aroma Characterization of Freshly Distilled Calvados. 1. Evaluation of Quality and Defects on the Basis of Key Odorants by Olfactometry and Sensory Analysis. J. Agric. Food Chem. 2002, 50, 424-432 (preceding paper in this issue)]. Of these, 16 of the 19 molecules that constitute the "aroma skeleton" were identified, including 5 esters, 2 ketones, 5 phenolic derivatives, 2 alcohols, and 2 carboxylic acids. Numerous compounds were also associated with odors found in part 1. These molecules can be considered as being responsible for the good quality of Calvados or, in contrast, for defects. Relative levels of some major olfactive compounds were also estimated and tentatively compared with olfactometric indices found in part 1. A good correlation was found in many cases. Two important markers of defects in Calvados were also identified. 3-Methylbut-2-en-1-ol leads to an "herbaceous" defect, and 1,1,3-triethoxypropane seems to give an "acrolein" defect in the product. "Floral" notes of the aroma of freshly distilled Calvados seem to be due to the presence of phenolic derivatives such as 2-phenylethanol and 2-phenylethyl acetate. Low-molecular-weight esters such as ethyl 2-methylpropanoate, ethyl 2-methylbutanoate, and 3-methylbutyl acetate give, in general, the "fruity" notes. However, the overall aroma of Calvados seems likely to be a subtle balance of various functionalized compounds.

Alcohols↗

PubMed2002

Comparison between the radical scavenging activity and antioxidant activity of six distilled and nondistilled mediterranean herbs and aromatic plants.

Thirty-six different extracts of six herbs and aromatic plants (fennel, common melilot, milfoil, lavandin cv. Super, spike lavender, and tarragon) were evaluated for their radical scavenging activity by the DPPH*, NBT/hypoxanthine superoxide, and *OH/luminol chemiluminescence methods, and for their antioxidant activity by the beta-carotene blenching test. The total phenolic content was also determined by the Folin-Ciocalteu method. The plant material included cultivated plants and their wastes after being distilled for essential oils. Both remarkably high phenolic content and radical scavenging activities were found for the ethyl acetate and dichloromethane fractions among the different plant extracts. In general, the distilled plant material was found to exhibit a higher phenolic content as well as antioxidant and radical scavenging activities than the nondistilled material. Ethyl acetate and dichloromethane extracts, and even some crude extract, of both distilled and nondistilled plants exhibited activities comparable to those of commercial extracts/compounds, thus making it possible to consider some of them as a potential source of antioxidants of natural origin.

Acetates↗

PubMed2004

Identification of trace volatile compounds in freshly distilled Calvados and Cognac using preparative separations coupled with gas chromatography-mass spectrometry.

Gas chromatography coupled with mass spectrometry (GC-MS) using both electron impact and chemical ionization detection modes led to the determination of the volatile composition of two samples of freshly distilled Cognac and two samples of freshly distilled Calvados. A total of 169 volatile compounds were directly identified in dichloromethane extracts obtained by liquid-liquid extraction. Trace compounds present in both spirits were characterized with the help of preparative separations. In a first step, groups of compounds were separated by preparative GC, and the fractions were analyzed on a polar stationary phase by GC-MS. In a second step, silica gel fractionation was used to separate them by polarity. In this study, 331 compounds, of which 162 can be considered as trace compounds, were characterized in both freshly distilled Cognac and Calvados. Of these, 39 are common to both spirits; 30 are specific to Cognac with numerous hexenyl esters and norisoprenoidic derivatives, whereas 93 are specific to Calvados with compounds such as unsaturated alcohols, phenolic derivatives, and unsaturated aldehydes.

Alcoholic Beverages↗

PubMed2006

Tartaric acid recovery from distilled lees and use of the residual solid as an economic nutrient for lactobacillus.

The recovery of tartaric acid (TA) from distilled vinification lees coming from the white and red winemaking technology was optimized using response surface methodology and Statistica 5.0 software. The sequential treatment of dissolving TA and further calcium tartrate (CaT) precipitation could be used to recover up to 92.4% of the initial TA when distilled white lees were used. The residual lees were employed as economic nutrients for lactic acid production by Lactobacillus pentosus CECT-4023 using hemicellulosic vine shoot hydrolysates as carbon source. Distilled lees after TA extraction used as nutrients provided values of lactic acid (18.4-18.9 g/L), global volumetric productivities (0.82-0.84 g/L.h), and product yields (0.69-0.70 g/g) similar to those achieved when using the general medium for Lactobacilli (18.6 g/L, 1.11 g/L.h, and 0.62 g/g, respectively) or lees without TA extraction (16.4-17.2 g/L, 0.96-1.21 g/L.h, and 0.61-0.66 g/g, respectively). This technology not only avoids pollutant disposal but also represents a commercial source of tartaric acid and economic nutrients for biotechnological processes.

Chemical Precipitation↗

PubMed2001

Experimental entanglement distillation and 'hidden' non-locality.

Entangled states are central to quantum information processing, including quantum teleportation, efficient quantum computation and quantum cryptography. In general, these applications work best with pure, maximally entangled quantum states. However, owing to dissipation and decoherence, practically available states are likely to be non-maximally entangled, partially mixed (that is, not pure), or both. To counter this problem, various schemes of entanglement distillation, state purification and concentration have been proposed. Here we demonstrate experimentally the distillation of maximally entangled states from non-maximally entangled inputs. Using partial polarizers, we perform a filtering process to maximize the entanglement of pure polarization-entangled photon pairs generated by spontaneous parametric down-conversion. We have also applied our methods to initial states that are partially mixed. After filtering, the distilled states demonstrate certain non-local correlations, as evidenced by their violation of a form of Bell's inequality. Because the initial states do not have this property, they can be said to possess 'hidden' non-locality.

Journal Article↗

PubMed2006

The distillation and volatility of ionic liquids.

It is widely believed that a defining characteristic of ionic liquids (or low-temperature molten salts) is that they exert no measurable vapour pressure, and hence cannot be distilled. Here we demonstrate that this is unfounded, and that many ionic liquids can be distilled at low pressure without decomposition. Ionic liquids represent matter solely composed of ions, and so are perceived as non-volatile substances. During the last decade, interest in the field of ionic liquids has burgeoned, producing a wealth of intellectual and technological challenges and opportunities for the production of new chemical and extractive processes, fuel cells and batteries, and new composite materials. Much of this potential is underpinned by their presumed involatility. This characteristic, however, can severely restrict the attainability of high purity levels for ionic liquids (when they contain poorly volatile components) in recycling schemes, as well as excluding their use in gas-phase processes. We anticipate that our demonstration that some selected families of commonly used aprotic ionic liquids can be distilled at 200-300 degrees C and low pressure, with concomitant recovery of significant amounts of pure substance, will permit these currently excluded applications to be realized.

Journal Article↗

PubMedDate not supplied

Using distilled water for the extraction of mucosal antibodies and the subsequent application in RSV neutralization test.

Virus neutralization (VN) is an important functional test for evaluating RSV vaccines, also encompassing in mucosal secretion of the respiratory tract considering the infection route. In our previous study, an immunoglobin extraction method described by Bergquist et al. was adopted for RSV ELISA, but it was not suitable for virus neutralization test due to the cell toxicity of the 2% saponin solution used for the antibody extraction. In order to overcome this problem, several solvents including distilled water were tested in the present study for the capacity to extract immunogloblins. Antibodies in the extracts were evaluated and compared by ELISA. Distilled water was as efficient as the 2% saponin solution for extraction of total IgA, RSV specific IgA and IgG. More importantly, the organ extracts obtained subsequently could be used for virus neutralization test without causing adverse effect on the cell culture. Therefore, distilled water was finally chosen as the solvent for immunoglobulin extraction from mucosal organs when both ELISA and virus neutralization test are required.

Animals↗

PubMedDate not supplied

Determination of the boiling-point distribution by simulated distillation from n-pentane through n-tetratetracontane in 70 to 80 seconds.

This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identical to those obtained by slower oven-heating rates. The boiling-point distribution of the reference gas oil is compared with that obtained with column oven heating at rates of 15 to 40 degrees C/min. The results show boiling-point distribution values nearly the same (1-2 degrees F) as those obtained with oven column heating from the initial boiling point to 80% distilled off. Slightly higher differences are obtained (3-4 degrees F) for the 80% distillation to final boiling-point interval. Nonetheless, allowed consensus differences are never exceeded. Precision of the boiling-point distributions (expressed as standard deviations) are 0.1-0.3% for the data obtained in the direct column-heating mode.

Journal Article↗

PubMed2001

Nonadditivity of bipartite distillable entanglement follows from a conjecture on bound entangled Werner states.

Assuming the validity of a conjecture given by DiVincenzo et al. [Phys. Rev. A 61, 062312 (2000)] and by Dür et al. [Phys. Rev. A 61, 062313 (2000)], we show that the distillable entanglement for two bipartite states, each of which individually has zero distillable entanglement, can be nonzero. We show that this also implies that the distillable entanglement is not a convex function. Our example consists of the tensor product of a bound entangled state based on an unextendible product basis with an entangled Werner state which lies in the class of conjectured undistillable states.

Journal Article↗

PubMed2001

Distillability, bell inequalities, and multiparticle bound entanglement.

We study the relation between violation of Bell inequalities and distillability properties of quantum states. Recently, Dür [Phys. Rev. Lett. 87, 230402 (2001)] has shown that there are some multiparticle bound entangled states which are nonseparable and nondistillable, that violate a Bell inequality. We prove that for all the states violating this inequality there exists at least one splitting of the parties into two groups such that some pure-state entanglement can be distilled, obtaining a connection between Bell inequalities and bipartite distillable entanglement.

Journal Article↗

PubMed2002

Gaussian transformations and distillation of entangled Gaussian states.

We prove that it is impossible to distill more entanglement from a single copy of a two-mode bipartite entangled Gaussian state via local Gaussian operations and classical communication. More generally, we show that any hypothetical distillation protocol for Gaussian states involving only Gaussian operations would be a deterministic protocol. Finally, we argue that the protocol considered by Eisert et al. [preceding Letter, Phys. Rev. Lett. 89, 137903 ()]] is the optimum Gaussian distillation protocol for two copies of entangled Gaussian states.

Journal Article↗

PubMed2005

Quantum key distillation from Gaussian states by Gaussian operations.

We study the secrecy properties of Gaussian states under Gaussian operations. Although such operations are useless for quantum distillation, we prove that it is possible to distill a secret key secure against any attack from sufficiently entangled Gaussian states with nonpositive partial transposition. Moreover, all such states allow for key distillation, when Eve is assumed to perform finite-size coherent attacks before the reconciliation process.

Journal Article↗

PubMed2005

Distillation of multipartite entanglement by complementary stabilizer measurements.

We propose a scheme of multipartite entanglement distillation driven by a complementary pair of stabilizer measurements to distill directly a wider range of states beyond the stabilizer code states (such as the Greenberger-Horne-Zeilinger states). We make our idea explicit by constructing a recurrence protocol for the 3-qubit state [formula: see text]. Noisy states resulting from typical decoherence can be directly purified in a few steps, if their initial fidelity is larger than a threshold. For general input mixed states, we observe distillations to hierarchical fixed points, i.e., not only to the state but also to the 2-qubit Bell pair, depending on their initial entanglement.

Journal Article↗

PubMed2006

Experimental entanglement distillation of two-qubit mixed states under local operations.

We experimentally demonstrate optimal entanglement distillation from two forms of two-qubit mixed states under local filtering operations according to the constructive method introduced by [F. Verstraete, Phys. Rev. A 64, 010101(R) (2001)10.1103/PhysRevA.64.010101]. In principle, our setup can be easily applied to distilling entanglement from arbitrary two-qubit partially mixed states. We also test the violation of the Clauser-Horne-Shinmony-Holt inequality for the distilled state from the first form of mixed state to show its "hidden nonlocality."

Journal Article↗

PubMed2006

Asymptotic violation of Bell inequalities and distillability.

A multipartite quantum state violates a Bell inequality asymptotically if, after jointly processing by general local operations an arbitrarily large number of copies of it, the result violates the inequality. In the bipartite case we show that asymptotic violation of the Clauser-Horne-Shimony-Holt inequality is equivalent to distillability. Hence, bound entangled states do not violate it. In the multipartite case we consider the complete set of full-correlation Bell inequalities with two dichotomic observables per site. We show that asymptotic violation of any of these inequalities by a multipartite state implies that pure-state entanglement can be distilled from it, although the corresponding distillation protocol may require that some of the parties join into several groups. We also obtain the extreme points of the set of distributions generated by measuring N quantum systems with two dichotomic observables per site.

Journal Article↗

PubMedDate not supplied

Storage of fungi using sterile distilled water or lyophilization: comparison after 12 years.

The methods used in our laboratory for maintaining culture collections of fungi, i.e. storage in sterile distilled water or lyophilization, were evaluated. Seventy-eight isolates belonging to seven genera were tested. After 12 years of preservation, survival rates associated with distilled water storage and lyophilization were 89.7% and 87.2% respectively. The viability of the dermatophytes after 8 years was confirmed using urease test media, the hair penetration test and dermatophyte test medium (DTM). The results showed that the procedure for maintaining cultures in distilled water is simple, inexpensive and reliable.

Biological Specimen Banks↗

PubMed2006

Citric acid production by Aspergillus niger on wet corn distillers grains.

AIMS: To determine which citric acid-producing strain of Aspergillus niger utilized wet corn distillers grains most effectively to produce citric acid. METHODS AND RESULTS: Citric acid and biomass production by the fungal strains were analysed on the untreated grains or autoclaved grains using an enzyme assay and a gravimetric method respectively. Fungal citric acid production on the grains was found to occur on the untreated or autoclaved grains. The highest citric acid level on the grains was produced by A. niger ATCC 9142. The autoclaved grains supported less citric acid production by the majority of strains screened. Biomass production by the fungal strains on the untreated or autoclaved grains was quite similar. The highest citric acid yields for A. niger ATCC 9142, ATCC 10577, ATCC 11414, ATCC 12846 and ATCC 26550 were found on the untreated grains. Treatment of the grains had little effect on citric acid yields based on reducing sugars consumed by A. niger ATCC 9029 and ATCC 201122. CONCLUSIONS: It is feasible for citric acid-producing strains of A. niger to excrete citric acid on wet corn distillers grains whether the grains are treated or untreated. The most effective citric acid-producing strain of A. niger was ATCC 9142. SIGNIFICANCE AND IMPACT OF THE STUDY: The study shows that the ethanol processing co-product wet corn distillers grains could be utilized as a substrate for the commercial production of citric acid by A. niger without treatment of the grains.

Aspergillus niger↗