Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 5 de 5
Filter
Add more filters










Database
Language
Publication year range
1.
J Forensic Sci ; 62(4): 962-970, 2017 Jul.
Article in English | MEDLINE | ID: mdl-28120513

ABSTRACT

We report about the X-ray powder diffraction characterization of crystalline materials used to produce genuine and counterfeit banknotes, performed with a single-crystal diffractometer that permits fast and nondestructive measurements in different 0.5-mm sized areas; 20-euro denomination genuine banknotes were analyzed, and results were compared with counterfeit banknotes. The analysis shows that the papers used to print real banknotes are composed, as expected, of cotton-based cellulose and titanium dioxide as crystalline additive, but different polymorphs of TiO2 for different emission countries are evidenced. The counterfeit banknotes are composed of cellulose based on wood pulp; moreover, an unexpected significant quantity of TiO2 was found to be mixed with calcite, indicating that the paper employed by forgers is not simply a common low-cost type. The crystalline index and intensity ratios between the peaks attributable to cellulose and fillers can provide additional information to trace back paper suppliers for forensic purposes.

2.
J Chromatogr A ; 1364: 303-7, 2014 Oct 17.
Article in English | MEDLINE | ID: mdl-25200529

ABSTRACT

In this work, we present for the first time a rapid and robust UHPLC-MS/MS method for analyzing taurine, GlcLA and GlcA in energy drinks simultaneously and without derivatization. The separation of three analytes was achieved using a Kinetex Hilic analytical column (100 mm × 4.6 mm i.d.) and a mobile phase formed by water (A) and acetonitrile (B) both with formic acid 0.1% at a flow rate of 0.8 ml min(-1) with isocratic elution in 3.5 min. Calibration curves were calculated using the method of standard addition in a concentration range from 2 to 6 mg/100 ml for taurine (R(2)>0.987), from 0.4 to 1.2 mg/100 ml for GlcLa (R(2)>0.997), and from 0.2 to 0.6 mg/100 ml for GlcA acid (R(2)>0.998). The validated method was applied to the analysis of nine commercial energy drinks. The level of taurine found ranged from 0.01 to 0.45 g/100 ml, and it matched with that reported in the labels of the analyzed energy drink samples.


Subject(s)
Energy Drinks/analysis , Glucuronates/analysis , Glucuronic Acid/analysis , Taurine/analysis , Chromatography, High Pressure Liquid/methods , Tandem Mass Spectrometry/methods
3.
Nat Prod Commun ; 5(8): 1317-20, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20839644

ABSTRACT

Seventeen different kinds of incenses were analyzed for the volatile components emitted during burning using a HS-SPME method coupled with GC-MS, in order to check their conformity to IFRA (International Fragrance Association) guidelines and 67/548/CEE Directive rules. A total of 51 volatiles were identified in the smoke of the incenses. They were represented mainly by aromatic compounds (17) and oxygenated monoterpenes (10), with esters (5) and aldehydes (4) being the most widespread volatiles in the former, and alcohols (4) and esters (4) in the latter. The aromatic ester benzyl benzoate and the oxygenated sesquiterpene patchouli alcohol were the most frequent volatile compounds, occurring in the smokes emitted from 10 and 8 kinds of incenses, respectively.


Subject(s)
Gas Chromatography-Mass Spectrometry/methods , Smoke/analysis , Solid Phase Microextraction/methods , Benzoates/analysis , Sesquiterpenes/analysis
4.
J Agric Food Chem ; 52(7): 1861-6, 2004 Apr 07.
Article in English | MEDLINE | ID: mdl-15053521

ABSTRACT

In wine making, the bacteriolytic activity of lysozyme has primarily been used to control the malolactic fermentation in wines. The use of lysozyme in musts before settling and the beginning of the alcoholic fermentation to inhibit the growth of lactic acid bacteria could be very beneficial. In a resistance test carried out in MT/b broth, lysozyme had greater antimicrobial activity toward Oenococcus oeni than Lactobacillus species. Several strains of wine bacteria belonging to Oenococcus proved sensitive to the bacteriolytic activity of lysozyme at low concentrations in both synthetic medium (MT/b) (50 mg/L), white must, or red must made with or without the skins (100 mg/L). Lactobacillus and Pediococcus strains survived at lysozyme concentrations of 200-500 and 500 mg/L, respectively, in MT/b and musts. Suspended solids in unclarified musts may strongly bind to lysozyme thereby causing its removal by filtration or centrifugation. One hour after lysozyme was added to musts, it was quantified by HPLC and found after centrifugation to be 40-50% and only 10% in musts made with or without the skins, respectively. Although appreciable amounts of lysozyme were bound to wine components, this did not appear to be a serious hindrance to lysozyme activity.


Subject(s)
Fruit/enzymology , Muramidase/metabolism , Vitis/enzymology , Wine/microbiology , Enzyme Stability , Fermentation , Lactobacillaceae/metabolism , Lactobacillus/metabolism , Pediococcus/metabolism
5.
J Agric Food Chem ; 50(20): 5605-11, 2002 Sep 25.
Article in English | MEDLINE | ID: mdl-12236685

ABSTRACT

Dimethyl dicarbonate (DMDC) was added to grape must and to synthetic media and results showed that, at 20 degrees C, 150 mg.L(-)(1) DMDC completely inhibited the fermentation of a grape must that was previously inoculated with 10(6) cells.mL(-)(1) Saccharomyces bayanus and Saccharomyces uvarum. Brettanomyces intermedius, Candida guilliermondii, Hansenula jadinii, Hansenula petersonii, Kloeckera apiculata, Pichia membranaefaciens, and Saccharomyces cerevisiae were inhibited by 250 mg.L(-)(1). Candida valida was inhibited in the presence of 350 mg.L(-)(1), whereas Hanseniaspora osmophila, Saccharomycodes ludwigii, Schizosaccharomyces pombe, and Zygosaccharomyces bailii required 400 mg.L(-)(1). Delay of fermentation (but not inhibition) was noted in the presence of 400 mg.L(-)(1) for the following cultures: Brettanomyces anomalus, Hanseniaspora uvarum, Metschnikowia pulcherrima, Schizosaccharomyces japonicus, Torulaspora delbrueckii, and Zygosaccharomyces florentinus. Acetobacter aceti and Lactobacillus sp. were completely inhibited using 1000 and 500 mg.L(-)(1) DMDC, respectively. The fermentation of a grape must inoculated with 10(6) cells.mL(-)(1) of different wine yeasts was delayed for 4 days after the prior addition of 200 mg.L(-)(1) of DMDC; 200 mg.L(-)(1) DMDC did not show any residual inhibitory effect after 12 h, nor did 300 mg.L(-)(1) 24 h after the addition. In cellar experiments, indigenously contaminated grape musts (with and without skins) showed a delay in fermentation of 48 h after the addition of only 50 mg.L(-)(1) DMDC. The possibility of using DMDC (as pure grade as commercially available) in grape must as a disinfectant for the decontamination of musts indigenously contaminated with wild yeast should be considered seriously, despite its apparent low solubility in water.


Subject(s)
Diethyl Pyrocarbonate/analogs & derivatives , Diethyl Pyrocarbonate/pharmacology , Fermentation , Vitis/metabolism , Vitis/microbiology , Wine/microbiology , Acetobacter/metabolism , Candida/metabolism , Food Handling , Lactobacillus/metabolism , Pichia/metabolism , Saccharomyces/metabolism , Saccharomyces cerevisiae/metabolism , Yeasts/metabolism
SELECTION OF CITATIONS
SEARCH DETAIL
...