Influence of the matrix in bioavailability of flufenoxuron, lufenuron, pyriproxyfen and fenoxycarb residues in grapes and wine.

The aim of this study is to ascertain the in vitro bioavailablity of pesticides that regulate and inhibit the growth of insects--flufenoxuron, lufenuron, pyriproxyfen and fenoxycarb--in grapes grown under good agricultural practice (GAP), while respecting the pre-harvest intervals (PHI) for critical conditions (CAP), in the most unfavorable conditions. The bioavailability of wines obtained from grapes in each assay and in standard solutions is also studied in order to establish matrix-related differences. Human gastric digestion, intestinal digestion and absorption were imitated. Porcine pepsin, porcine pancreatin, bile salts and semipermeable cellulose dialysis tubing were used. The analysis of the residues of the insecticides studied was performed by extraction with the QuEChERS method, and determination was with HPLC-MS. In all cases it was observed that the pesticides can be ordered according to their dialyzation capacity: fenoxycarb>pyriproxyfen>lufenuron>flufenoxuron. The different matrices can also be ordered according to the matrix effect they impose on the dialysis: grape>wine>standards. The highest percentages of dialyzation for grape and wine matrices are achieved for fenoxycarb (3.27%) and pyriproxifen (2.04%) in wine.

Bioavailability of insect growth regulator residues in citrus.

The aim of this study was to increase the knowledge in the field of bioavailability of pollutants in agricultural food samples. Bioavailability of flufenoxuron, lufenuron, pyriproxyfen and fenoxycarb was studied in a common commodity as mandarin in vitro. Not only was it studied in fresh fruit but also in standards and canned mandarin to be able to establish matrix-related differences. Human gastric digestion, intestinal digestion and absorption were imitated. Porcine pepsin, porcine pancreatin, bile salts and semipermeable cellulose dialysis tubing were used. Dialysis values were lower than 15% and followed this order: standards > processed samples > fresh samples. The highest dialyzable values were observed for fenoxycarb and pyriproxyfen. The higher the digested amount of pesticide, the higher the dialysed amount.

Influence of several fungicides on the antioxidant activity of red wines (var. Monastrell).

The antioxidant activity of wines obtained from grapes treated with six fungicides (famoxadone, fenhexamid, fluquinconazole, kresoxim-methyl, quinoxyfen and trifloxystrobin) was investigated. Two field trials in triplicate were carried out for each formulation of the fungicide at the recommended dose of the manufacturer. The first trial was carried out under good agricultural practices (GAP), following the recommended pre-harvest interval, and the second one under critical agricultural practices (CAP) that involves treating the same field just before the harvest. The residue levels were determined by gas and liquid chromatography coupled to mass detectors (GC-MS and LC-MS). The antioxidant activity was determined in the wines obtained from the thirteen trials including one control, six from treated grapes obeying the pre-harvest interval, and six from grapes treated at the day of harvest or at most unfavorable conditions. Elimination of 40-100% of the initial fungicide residues present in grapes was observed during the wine-making process. It can be inferred from the results that the use of these fungicides did not produce any decrease of the antioxidant activity in the wines (7.19 +/- 0.22 mmol Trolox/L for the blank wine versus a range of 6.45 +/- 0.82 mmol Trolox/L to 10.06 +/- 0.59 mmol Trolox/L for the treated wines) at the pre-harvest interval and most unfavorable conditions. Nevertheless, the presence of famoxadone, kresoxim-methyl and quinoxyfen increased the antioxidant activity and this was directly related to their residue levels in the grapes. Also, the wine phenolic composition was altered in variable intensity by the presence of the fungicide residues.

Bioavailability of insect growth regulators in citrus and stone fruits.

The aim of this study was to offer data about the bioavailability of flufenoxuron, lufenuron, pyriproxyfen and fenoxycarb in common commodities like mandarin, apricot and peach. The in vitro bioavailability of the compounds was studied not only in fresh fruit but also in standards and canned food in order to establish possible differences according to the matrix. The gastric digestion was simulated with porcine pepsin at pH 2, for 2 h in a shaking water bath at 37 degrees C. The intestinal digestion was simulated with porcine pancreatin at pH 7, for 2 h in a shaking water bath at 37 degrees C. The intestinal absorption was simulated with cellulose dialysis tubing filled with a solution of sodium carbonate. No in vitro bioavailability was observed in mandarin, peach and apricot samples spiked at the concentrations generally found in the market for the raw and processed commodities. In standards, the dialysis started at the level of 0.25 mg/kg. This is an approximation to the pesticide digestion and absorption in humans.

Removal of pesticides from white wine by the use of fining agents and filtration.

The effects of four clarification agents (bentonite, charcoal, PVPP and potassium caseinate) on the removal of residues of three fungicides (famoxadone, fluquinconazole and trifloxystrobin) applied directly to a racked white wine, elaborated from Airen variety grapes from the D.O. Region of Jumilla (Murcia, Spain) are studied. The clarified wines were filtered with 0.45 microm nylon filters to determine the influence of this winemaking process in the disappearance of fungicide residues. Hydro-alcoholic solutions with the three fungicides at concentrations of 1 and 2 ppm were then added through intense stirring to each of the containers. Two hours later, the corresponding clarifying agent was added with intense stirring for some minutes. The containers were then sealed and left to settle for five days. Once the clean wines had been racked, they were filtered through nylon 0.45 microm pore filters. All assays were performed three times. Analytical determination of fluquinconazole and trifloxystrobin was performed by gas chromatography with an electron captor detector (ECD), while that of famoxadone was made using an HPLC-DAD. For the three fungicides, the highest elimination is produced with the clarification by charcoal, reaching Levels of removal of 100% in all cases. For the four clarifying agents, the highest elimination is produced for the fluquinconazole residues. The fungicide which is retained most in the lees is famoxadone, since it has the lowest solubility of the three pesticides studied. The highest percentage of residues in the lees is obtained for the assay with charcoal. The filtration process of the clarified wines using the four agents studied is not effective, since the elimination percentage is generally lower than 10% of the initial residues in the non-clarified wines.

Dissipation of insect growth regulators in fresh orange and orange juice.

It was studied the dissipation rates of fenoxycarb, Lufenuron, flufenoxuron and pyriproxyfen from their application on navelina orange crops to the production of orange juice. Supervised trials were carried out for the phytosanitary treatments under two situations, one according to Good Agricultural Practices (GAP) and the other one with Critical Agricultural Practices (CAP). Samples of both situations were transformed into orange juice according to the current industrial process. The analytical methodology included acetone and dichloromethane/petroleum ether extraction and aminopropyl-based cleanup. Method validation followed SANCO Guidelines. The final objective was the determination of the exposure to the residues in raw and processed orange when good and critical agricultural conditions are used in the field.

Influence of fungicides on grape yeast content and its evolution in the fermentation.

The influence of six fungicides (famoxadone, fenhexamid, fluquinconazole, kresoxim-methyl, quinoxyfen, trifloxystrobin) on the yeast content in harvested grapes has been studied along with their effect on it during the wine-making process. Two treatments were carried out with authorized formulates at the manufacturer doses. The first was carried out under good agricultural practices, obeying the security times, and the second one under critical conditions, applied on the day of harvesting. The grapes were harvested two hours after the application. During the wine-making process, samples were taken at 1, 5, 12 and 20 days after the start. The levels observed in the control sample (1.9 log CFU/cm2) were similar to previous studies. The counts in all treated samples were higher than the control sample, without adverse effect of the pesticides on the yeast count even in the grapes treated on the day of harvest. As with the observations on grapes, no effect of the pesticides on the fermentation count was observed. All counts on the treated samples were higher than the control sample. The treatment on the day of harvest did not have any effect on the fermentation count, with superior results being obtained for all the pesticides.

Disappearance of fenhexamid residues during wine-making process.

The main objective of this work was the study the influence of different wine-making techniques on the pesticide residue elimination from grapes to wine. In order to that, the maceration time effect (6 and 15 days) was studied on the final fenhexamid residue content in wine. And also, the influence of a prefermentative maceration at low temperatures (5 and 15 degrees C during three days of the maceration period) on the residue disappearance was determined in both maceration times. Determination of the residues of fenhexamid was made by GC-ECD, following extraction by an on-line micro method, with a mixture of acetone/dichloromethane (50/50 V/V) as extractant. The maceration time does not produce significant differences in the final pesticide content in wine. However, if the prefermentative temperature increases, there is a high elimination of the fungicide residues. The highest fungicide elimination was obtained in wines with long maceration and a prefermentation at 5 degrees C.

Aspectos clínicos de la folie à trois: a propósito de un caso / Clinical perspective in the folie à trois: a case report

El trastorno psicótico inducido es un cuadro clínico poco frecuente. Describimos un caso en el que están implicados tres miembros de una misma familia. Se analizan los factores etiológicos, la dinámica familiar y el entorno social en las psicosis inducidas (AU)

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