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The impact of two parameters (temperature and duration) on the radical scavenging capacity of individual compounds, and total extracts found in coffee was investigated. Phenolic coffee extracts of light (200 °C), medium (225 °C) and dark (235 °C) roasted coffees in a range of 0–30 min were analyzed by an on-line RP-HLPC-ABTS•+ decolourization assay. This study revealed a general decrease of radical scavenging capacity related to native phenolic compounds. Processing coffee beans leads to generation of up to 10 new radical scavengers. The roasting process influences not only color and taste in coffees, but also the radical scavenging capacity of coffee as well. Phenolic content in roasted coffee and green coffee is very different. Six compounds identified as caffeoylquinic acids and dicaffeoylquinic acids, endowed with radical scavenging capacity were found in green coffee, whereas depending on the roasting process, roasted coffees can present up to 16 different radical scavengers. The compounds formed during the roast are most likely chlorogenic acids derivatives, of which 4 could be clearly identified as two feruloylquinic acids and two caffeoylquinides. In longer roasting durations, these molecules are subjected to auto-degradation, thus total radical scavenging capacity in coffee decline along with roasting (duration and temperature). [ABSTRACT FROM AUTHOR]

This paper provides quantitative information on the transfer of TBT (tributyltin) and TPhT (triphenyltin) from sludged soil to cultivated lettuce. The effect of their initial concentrations in the soil (varying from 20 to 50μg(Sn)kg−1 for each triorganotin), sludge amount (between 1% and 9%), and cultivation duration (32–54 days) was evaluated by means of experimental designs. The impact of the cultivation temperature at 13°C and 19°C on organotin fate in the soil/plant system was also considered. The final concentration of a given organotin in the plant roots was found to depend directly on its initial concentration in the soil. A total of (85±15)% of initial TBT in the soil was still present at the end of the experiments, regardless of the cultivation duration. Consequently, TBT appeared to be taken up by lettuce continually. A total of (75±5)% of TPhT was found to be degraded in the soil at 54 days. So, this compound could have been taken up by the plant at the beginning of the cultivation. Sludge amount seemed to have a negative effect on TPhT concentration in a plant at 32 days. This could be due to the quantitative TPhT sorption onto the sludge, observed just after spiking. Organotin plant uptake appeared to be more important at 19°C than at 13°C. TBT and TPhT were mainly accumulated in the roots, and up to 2% and 10% of TPhT and TBT, respectively, were translocated to the shoots. Despite TPhT degradation, products in large amounts were present in the soil and were not significantly taken up by the plant. They possibly remained immobilized on solid phases of the sludged soil. [Copyright &y& Elsevier]

Abstract: The persistence of tributyltin (TBT) and triphenyltin (TPhT) in soils was studied, taking into consideration the quantity of sewage sludge, TBT and TPhT concentrations in soil as well as the soil pH. The organotin compounds (OTC) were introduced into the soil via a spiked urban sludge, simulating agricultural practise. OTC speciation was achieved after acidic extraction of soil samples followed by gas chromatography–pulsed flame photometric analysis (GC–PFPD). Leaching tests conducted on a spiked sludge showed that more than 98% of TBT are sorbed on the sludge. TBT persistence in soil appeared to depend on its initial concentration in sludge. Thus, it was more important when concentration is over 1000μg(Sn)kg−1 of sludge. More than 50% of the initial TBT added into the soil were still present after 2 months, whatever the experimental conditions. The main degradation product appeared to be dibutyltin. About 90% of TPhT were initially sorbed on sludge, whatever the spiking concentration in sludge was. However, TPhT seemed to be quantitatively exchangeable at the solid/liquid interface, according to the leaching tests. It was also significantly degraded in sludged soil as only about 20% of TPhT remain present after 2 months, the monophenyltin being the main degradation product. pH had a significant positive effect on TBT and particularly TPhT persistence, according to the initial amounts introduced into the soil. Thus, at pH over 7 and triorganotin concentration over 100μg(Sn)kg−1, less than 10% of TBT but about 60% of TPhT were degraded. When the sludge was moderately contaminated by triorganotins (typically ⩽50μg(Sn)kg−1 in our conditions) the pH had no effect on TBT and TPhT persistence. [Copyright &y& Elsevier]

Because organotin compounds (OTC) are widely used in many fields of activity, they have become an ubiquitous environmental presence. The presence of organotins in the environment impacts upon food safety, making it important to monitor the levels of organotin pesticides in fruits and vegetables. Nevertheless, only a few studies have been published on organotin speciation in plants. The objective of the present study was to evaluate and optimise a specific procedure based on pressurised solvent extraction (PSE) that is suitable for monitoring organotin content in vegetables. In ASE, solvents are used at elevated temperatures and pressures to increase the rate and efficiency of the extraction process. The results from this procedure were compared to those from the technique usually employed, solid/liquid extraction (SLE) performed in an acidic solvent by mechanical shaking. Three extracting solutions were tested—methanol, ethyl acetate and a mixture of methanol and ethyl acetate—and the mixture was found to give the most quantitative results while preserving the speciation. French bean and lettuce leaves as well as potato tubers were used as the plant materials. These vegetables were considered because they are the vegatables consumed in the most quantities in Europe. The study focuses on trisubstituted OTCs, which are the most toxic tin species. The samples were spiked with four trisubstituted organotins: tributyltin (TBT), triphenyltin (TPhT), tricyclohexyltin (TcHexT) and trioctyltin (TOcT). The influence of the pressure and the temperature of the PSE on the quantitativity of the process and on species preservation was evaluated using the experimental design methodology. The optimised PSE allowed detection limits down to 1–2 ng (Sn) g−1 to be reached. These are higher than those obtained by SLE (0.1–1 ng (Sn) g−1). Although the repeatability is similar for both PSE and SLE (2–12% for triorganotin compounds), this appears to be highly time-dependent in the case of SLE. Comparison with SLE confirms that PSE is an interesting tool for vegetable analysis considering the satisfactory OTC preservation and repeatability obtained for a relatively short extraction duration (only 15 min against 2–12 h for SLE). [ABSTRACT FROM AUTHOR]

Three sample preparation methods (hydrodistillation, pressurized liquid extraction and static headspace) used for the extraction of terpenoids from various food matrices (cinnamon, thyme, cumin, fennel, clove, nutmeg and orange) were compared. Extracts were analyzed by gas chromatography−mass spectrometry qualitatively and quantitatively using a wide range of terpenoid standards. Quantitative and qualitative differences were found in the chemical compositions of the analyzed samples depending on the extraction method. Headspace (HS) was the most efficient extraction method as HS extracts were the most concentrated. This allows to reach the lowest limits of detection and quantification for the different standards extracted by HS (eugenol LOD by HS is 0.0022 µg/g against 0.03 µg/g by liquid injection). Furthermore, as HS is a simple, rapid, solventless and automated extraction method, it should be considered as an alternative technique to hydrodistillation or pressurized liquid extraction when quantifying terpenoids in food matrices. [ABSTRACT FROM AUTHOR]

Deep eutectic solvents (DESs) were investigated as extracting solvent for headspace single-drop microextraction (HS-SDME). The extraction efficiency of 10 DESs mainly composed of tetrabutylammonium bromide (N4444Br) and long-chain alcohols was evaluated for the extraction of terpenes from six spices (cinnamon, cumin, fennel, clove, thyme, and nutmeg). The DES composed of N4444Br and dodecanol at a molar ratio of 1:2 showed the highest extraction efficiency and was selected to conduct the extractions of terpenes in the rest of the study. HS-SDME was optimized by design of experiments. Only two parameters from the four studied showed a significant influence on the efficiency of the method: the extraction time and the extraction temperature. The optimal extraction conditions were determined by response surface methodology. All extracts were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). More than 40 terpenes were extracted and identified in nutmeg, the richest extract in terpenes in this study. Quantitative analysis based on 29 standards was conducted for each extract. Good linearity was obtained for all standards (R2 > 0.99) in the interval of 1 to 500 μg/g. Limits of quantification ranged from 0.47 μg/g (borneol) to 86.40 μg/g (α-farnesene) with more than half of the values under 2 μg/g. HS-SDME is simple, rapid, and cheap compared with conventional extraction methods. The use of DESs makes this extraction method "greener" and it was shown that DESs can be suitable solvents for the extraction of bioactive compounds from plants. [ABSTRACT FROM AUTHOR]

[Display omitted] • Innovative nanostructurated device for thiol analysis. • The device was easy to use and allowed low molecular thiols quantification. • Thiols were quantified in simple and biological matrices. • Reduced glutathione concentration was successfully evaluated in rat plasma. Thiols are very important molecules in the biomedical field involved for example in redox homeostasis. Their detection and quantification remain difficult due to their poor stability (oxidation) linked to their strong reactivity towards other thiols (by the formation of S-S bonds) or other interfering molecules in the medium. Cellulose membranes with immobilized gold nanoparticles (AuNP) were developed to capture and quantify thiols in simple and complex matrices. This device was first optimized and characterized in terms of nanostructuration and thiol adsorption. N -Acetylcysteine (NAC) and reduced glutathione (GSH), chosen as model molecules, were filtered through the device demonstrating a maximal adsorption capacity of 270 and 60 nmol respectively. In a second step, the adsorbed species were subjected to ligand exchange using a more reactive thiol, dithiothreitol. The results showed release rates of approximately 90% for NAC and GSH. Finally, the amount of endogenous GSH in rat plasma was determined without any pretreatment. For the first time to our knowledge, a nanostructured device for the capture, selective and sensitive quantification of thiols is proposed. This device is easy to handle and overcomes matrix effects. Moreover, the very large concentration factor induced by this technology will be a valuable asset to decrease the quantification limits of analytical methods. [ABSTRACT FROM AUTHOR]

Highlights: [•] Investigation of the thermal stability of phospholipids extracted from coffee roasted beans. [•] PL coffee beans contain only PC and PI. [•] Use of normal phase HPLC-ELSD to identify and quantify PL classes. [•] Decreases of PI and PC contents were observed as a consequence of increases of temperature and durations treatments. [•] PI is more thermo sensitive to thermo-degradation than PC. [Copyright &y& Elsevier]

Headspace solid-phase microextraction (HS-SPME) followed by gas chromatography-mass spectrometry analysis (GC-MS) was used to investigate the volatile compounds from oxidised phosphatidylcholine molecular species. 1-stearoyl-2-oleoyl- sn-glycero-3-phosphocholine (SOPC) and 1-stearoyl-2-linoleoyl- sn-glycero-3-phosphocholine (SLPC) were chosen as models. The influence of several parameters on the efficiency of volatile oxidised compounds (VOCs) microextraction, such as type of fibre, extraction duration and temperature were studied. The best results were obtained with a polydimethylsiloxane/divinylbenzene (PDMS/DVB) fibre used at 50 °C during 25 min. The effect of oxidation temperature on the yield of VOCs from SOPC and SLPC was investigated. Oxidative kinetics of SOPC and SLPC were investigated by measuring both the production of VOCs and the degradation of starting materials. More than 30 VOCs were detected by means of the reference mass spectra of the National Institute of Standards and Technology mass spectral library, and most of them were further confirmed by comparing their mass spectra and retention time with those obtained from authentic reference compounds under the same analytical conditions. Moreover, the origins of VOCs from oxidised PLs were studied by comparing those obtained from their corresponding triacylglycerides under the same experimental conditions. The main VOCs identified from oxidised SOPC were (E)-2-decenal, nonanal and octanal and from oxidised SLPC were (E)-2-heptenal, (E)-2-octenal and (E, E)-2,4-decadienal. The proposed method was applied to a real food sample, soy lecithin. [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Background: Previously, we have reported the ability of thiamine (vitamin B1) to induce resistance against Plasmopara viticola in a susceptible grapevine cv. Chardonnay. However, mechanisms underlying vitamins, especially, thiamine-induced disease resistance in grapevine are still largely unknown. Here, we assessed whether thiamine could modulate phenylpropanoid pathway-derived phytoalexins in grapevine plants, as well as, the role of such secondary metabolites in thiamine-induced resistance process to P. viticola. Results: Our data show that thiamine treatment elicited the expression of phenylpropanoid pathway genes in grapevine plants. The expression of these genes correlated with an accumulation of stilbenes, phenolic compounds, flavonoids and lignin. Furthermore, the total anti-oxidant potential of thiamine-treaded plants was increased by 3.5- fold higher level as compared with untreated-control plants. Four phenolic compounds are responsible of 97% of the total anti-oxidant potential of thiamine-treated plants. Among these compounds, is the caftaric acid, belonging to the hydroxy-cinnamic acids family. This element contributed, by its own, by 20% of this total anti-oxidant potential. Epifluorescence microscopy analysis revealed a concomitant presence of unbranched-altered P. viticola mycelia and stilbenes production in the leaf mesophyll of thiamine-treated inoculated plants, suggesting that stilbenes are an important component of thiamine-induced resistance in grapevine. Conclusion: This work is the first to show the role of thiamine, as a vitamin, in the modulation of grapevine plant secondary metabolism contributing to an enhanced resistance to P. viticola, the most destructive fungal disease in vineyards. [ABSTRACT FROM AUTHOR]