Search results for "COF"
showing 10 items of 757 documents
L'Oceania francofona: tra tradizione e innovazione
2018
Le isole francofone dell’Oceano Pacifico – arcipelago della Polinesia francese, Nuova Caledonia, Wallis e Futuna, Vanuatu – sono caratterizzate dalla profonda variegatura della loro diversità storica e politica. Se alcuni territori sono indipendenti, altri hanno subìto o subiscono il controllo statunitense, francese, inglese, neo-zelandese, australiano e cileno. Si tratta di un’area che soltanto forzatamente può essere definita francofila e francofona dal momento che, dal punto di vista demografico, queste isole ospitano soltanto il 2,5% della popolazione totale dell’Oceania che conta su una maggioranza di anglofoni; e che si registra la presenza, accanto alla lingua francese, di ben altre …
Analysis of mycotoxins in coffee and risk assessment in Spanish adolescents and adults.
2015
Mycotoxins are toxic compounds produced by fungal secondary metabolism that cause toxicological effects. Coffee is a highly popular beverage that is susceptible to contamination by mycotoxigenic fungi. The aim of the present study was to determine the presence of the following 21 mycotoxins in coffee using liquid chromatography tandem mass spectrometry (LC-MS/MS-IT): aflatoxin B1, B2, G1 and G2; ochratoxin A; nivalenol; deoxynivalenol; 3-acetyldeoxynivalenol; 15-acetyldeoxynivalenol; diacetoxyscirpenol; neosolaniol; T-2 and HT-2 toxin; sterigmatocystin; enniatin A, A1, B, and B1; beauvericin; and fumonisin B1 and B2. We aimed to determine differences by coffee process (coffee maker, electri…
Influence of different coffee drinks preparations on ochratoxin A content and evaluation of the antioxidant activity and caffeine variations.
2011
Coffee is one of the most frequently consumed beverages in North America and Europe. It is well known that coffee contains caffeine and that coffee beans can be contaminated by Ochratoxin A (OTA). The operating conditions however affect OTA and caffeine extraction from the roasted coffee. OTA content found in the beverages can be greater than that found in the roasted coffee used to prepare it, representing a potential OTA related risk factor for the human health. Moreover the coffee beans and coffee based beverages have an anti oxidant activity. This study investigates the OTA content, the amount of caffeine, and the antioxidant activity in five different preparations: American coffee, Mok…
Improved sensitivity of ochratoxin A analysis in coffee using high-performance liquid chromatography with hybrid triple quadrupole-linear ion trap ma…
2016
A novel and sensitive method utilising high-performance liquid chromatography coupled to triple quadrupole-linear ion trap mass spectrometry (LC-QqQLIT-MS/MS) was developed in order to analyse the content of ochratoxin A (OTA) in coffee samples. The introduction of the triple-stage MS scanning mode (MS(3)) has been shown to increase greatly sensitivity and selectivity by eliminating the high chromatographic baseline caused by interference of complex coffee matrices. The analysis included the sample preparation procedure involving extraction of OTA using a methanol-water mixture and clean-up by immunoaffinity columns and detection using the MS(3) scanning mode of LC-QqQLIT-MS/MS. The propose…
Influence of roasting and different brewing processes on ochratoxin A content in coffee determined by high-performance liquid chromatography-fluoresc…
2008
A rapid and reliable procedure has been developed for the determination of ochratoxin A (OTA) in green and roasted coffee. The method consists of extraction of the sample with methanol-5% aqueous sodium hydrogen carbonate/1% PEG8000 (20:80), followed by immunoaffinity column (IAC) clean-up and, finally, high-performance liquid chromatography (HPLC) determination with fluorimetric detection. Mean recoveries for green and roasted coffee spiked at different levels ranging from 94 and 105% were obtained. The limit of determination (S/N = 3) was 0.032 ng g(-1) and the precision (within-laboratory relative standard deviation) was 6%. The method described has been used to assess the influence of r…
Ochratoxin A in instant coffee in Italy
2012
Abstract The occurrence of ochratoxin A (OTA) in instant coffee from different brands and types was assessed. The survey covered 44 soluble coffees, 10 of which were decaffeinated, and 6 coffee products; the samples were collected in supermarkets and retail stores of Italy in 2011. The OTA was extracted, cleaned-up by immunoaffinity columns, and detected by HPLC-fluorescence detection. The detection and quantification limits were 0.05 and 0.2 μg/kg, respectively. Recovery, from samples spiked at levels of 0.5, 3.0, and 6.0 μg/kg, was 86.0 ± 7.1%, 91.0 ± 4.2%, and 91.7 ± 5.9% respectively. Forty-eight samples (96%) contained OTA at levels ranging from 0.32 to 6.40 μg/kg, always below the Eur…
Influencia del procesado industrial sobre las características químico-físicas y contenido en lípidos y antioxidantes del salvado de arroz
2009
Se investigaron las características químico-físicas de los salvados de arroz en distintos momentos de su procesado industrial, incluyendo materia prima (salvados de arroz blanco y vaporizado), salvado peletizado y salvado desgrasado. Se determinó la humedad, la acidez y el índice de peróxidos. Utilizando extractos en éter de petróleo y cromatografía de gases, se estableció el contenido lipídico total y los perfiles de los ácidos grasos. Mediante HPLC se determinaron los tocoferoles y el γ-orizanol. El salvado de arroz vaporizado mostró la mayor concentración de lípidos y la menor acidez, lo que indica que el vaporizado es el proceso más eficaz para estabilizar el salvado. Los ácidos oleico,…
Therapeutic effect of enhancing endothelial nitric oxide synthase (eNOS) expression and preventing eNOS uncoupling
2011
Nitric oxide (NO) produced by the endothelium is an important protective molecule in the vasculature. It is generated by the enzyme endothelial NO synthase (eNOS). Similar to all NOS isoforms, functional eNOS transfers electrons from nicotinamide adenine dinucleotide phosphate (NADPH), via the flavins flavin adenine dinucleotide and flavin mononucleotide in the carboxy-terminal reductase domain, to the heme in the amino-terminal oxygenase domain. Here, the substrate L-arginine is oxidized to L-citrulline and NO. Cardiovascular risk factors such as diabetes mellitus, hypertension, hypercholesterolaemia or cigarette smoking reduce bioactive NO. These risk factors lead to an enhanced productio…
A 18F-labeled dibenzocyclooctyne (DBCO) derivative for copper-free click labeling of biomolecules
2016
The new prosthetic group 18F-TEG-DBCO (dibenzocyclooctyne) can be prepared within a total reaction time of 60 min including purification with an overall yield (n.d.c.) of 34 ± 5%. Copper-free click cycloadditions with an azido-cRGD, a folate-azide and two α-MSH analogue azido-peptides resulted in very high RCYs and fast reaction kinetics.
Low temperature measurements by infrared spectroscopy in $CoFe_2O_4$ ceramic
2012
In this paper results of new far-infrared and middle-infrared measurements (wavenumber range of 4000cm-1 - 100cm-1) in the range of the temperature from 300K to 8K of the CoFe2O4 ceramic are presented. The bands positions and their shapes are the same in the wide temperature range. The quality of the sample was investigated by X-ray, EDS and EPMA studies. The CoFe2O4 reveals the cubic structure (Fd-3m) in the temperature range from 85K to 360 K without any traces of distortion. On the current level of knowledge the polycrystalline CoFe2O4 does not exhibit phase transition in the temperature range from 8 K to 300 K.