Residues of spiroxamine in grapes following field application and their fate from vine to wine

Dissipation of the fungicide spiroxamine in grapes of two vine varieties, Roditis and Cabernet Sauvignon, exposed to field treatments was evaluated. Vines of a grape vineyard located in central Greece were sprayed once or twice with a commercial formulation of the fungicide at 30 g a.i./hL. Residues in grapes, must, and wine were determined by gas chromatography/IT-MS after extraction with cyclohexane-dichloromethane (9:1), with a limit of quantitation 0.02 mg/kg in grapes and 0.012 mg/kg in wine. Under field conditions, spiroxamine dissipation on grapes was faster during the first 2 weeks and then slower to the sixth week. About 7 days after application, half of the initial spiroxamine concentration remained on the grapes; the respective proportion at 42 days was about 10%. At 14 and 35 days, residues were lower than 0.44 and 0.22 mg/kg, respectively, values below the maximum residue levels set by the European Union (1 mg/kg). Spiroxamine residues transferred from grapes into the must and through the vinification process into the wine were also studied. Mean transfer factors of 0.26 and 0.55 were found from grapes into wine for the wines obtained without maceration and with maceration, respectively. Residues in wine, prepared from grapes with a spiroxamine content of 0.11-0.20 mg/kg, varied from <0.026 to 0.09 mg/kg. Spiroxamine diastereomer B was found to dissipate slower than diastereomer A in the field as well as during the vinification process.     

Evaluation of teflubenzuron residue levels in grapes exposed to field treatments and in the must and wine produced from them.

Dissipation of benzoylurea insecticide teflubenzuron in grapes exposed to field treatments was evaluated. Vines of a white grape vineyard located in central Greece were sprayed twice, at a 28-day interval, with a commercial formulation of the insecticide at 12 g of active ingredient/100 L. Residues were determined by HPLC diode array detection, after ethyl acetate extraction and cleanup on silica phase cartridges, with a detection limit of 0.005 mg/kg. Under field conditions teflubenzuron residues in grapes were found to be very stable with no significant reduction for the whole experimental period of 49 days. However, residues were slightly lower than the maximum residue limits set by individual countries. The fate of teflubenzuron during the vinification process was also studied. Residues were found to be transferred completely into the must but, due to their high affinity for the suspended matter, were removed by approximately 98%; thus, very low concentrations were detected in the produced wine. Among various clarifying agents studied, charcoal was the only one found to be effective for removing teflubenzuron residues from wine.     

Residues of azoxystrobin from grapes to raisins

Azoxystrobin, a fungicide of the strobilurin group, has an European Union maximum residue level (MRL) of 2 mg/kg for grapes. This work aimed to assess residues on fresh and washed grapes and on raisins following processing with (i) alkali treatment and sun drying and (ii) sun drying only. QUADRIS 25% SC was applied according to good agricultural practice for two consecutive years on a typical cv. Thomson seedless and a seed-producing clone. Samples were collected 0, 15, and 21 days postapplication and analyzed using gas chromatography/electron capture detection; recoveries were 86 +/- 12% for grapes and 99 +/- 15% for raisins. Residues on grapes were 0.49-1.84 mg/kg, and washing removed 75% of the residue. Residues in raisins produced from seedless grapes were 0.51-1.49 (treatment 1) and 1.42-2.08 mg/kg (treatment 2), with residue transfer factors sometimes >1, even following alkali treatment, which reduced residues considerably. To avoid trade problems, a higher MRL for raisins is necessary.     

Fate of iprovalicarb, indoxacarb, and boscalid residues in grapes and wine by GC-ITMS analysis

The behavior in field and the transfer from grapes to wine during winemaking of iprovalicarb, indoxacarb, and boscalid was studied. The residue levels found in grapes were far below the MRLs set for grapes in EU, accounting at harvest time 0.81, 0.43, and 4.23 mg/kg for iprovalicarb, indoxacarb, and boscalid, respectively. The residue levels in the samples treated with boscalid may have residual problems (due to an accumulation effect) if repeated field treatments will be performed. Winemaking experiments showed a complete transfer of all pesticide from grapes to the must, while in wine the residues were low or negligible due to the adsorbing effect of lees and pomace. The clarification experiments showed a good removal of pesticide residues from the wine media, for all pesticides. The GC-ITMS method showed good performance with adequate recoveries ranging from 75 to 115%, and good method limits of quantitation (LOQs) and of determination (LODs) far below MRLs.     

Fate of quinoxyfen residues in grapes, wine, and their processing products

Quinoxyfen is a new fungicide that belongs to the family of the quinolines, recently introduced to control powdery mildew (Uncinula necator). In this paper the fate of quinoxyfen residues from vine to wine and in their processing products was studied. After the last of four applications at the recommended rate, 0.38 mg/kg of residue was found on the grapes, which is under the legal limit fixed in Italy (0.5 mg/kg). The degradation rate was according to a pseudo-first-order kinetics (r = 0.964) and the half-life was 7.24 days. Vinification was carried out with and without maceration. During the vinifications without maceration <50% of the residues passed from the grapes to the musts. Separation of the lees (8%) from the must by centrifugation caused no detectable residues in centrifuged must. At the end of fermentation with and without maceration no quinoxyfen residues were determinable in the wine. No effect on the alcoholic or malolactic fermentation was observed even in the presence of higher quinoxyfen concentrations than those found in the grapes at harvest time. During fermentation, the yeasts partially degraded the pesticides and completly adsorbed them. Bacteria, on the other hand, do not have any degradative effect on the pesticides. The raisins obtained by sun-drying did not contain any residues, whereas those obtained by oven-drying show the same amount of residues as in the fresh grapes. During the sun-drying process the fruit weight decreased by a factor of 4; the decrease in the oven-drying was equivalent. Samples of dregs and liquid lees, fortified with high levels of quinoxyfen. were double-distilled. The first dregs distillate, with an alcohol content of 32.1%, did not show any residues, whereas the first lees distillate, with an alcohol content of 34.5%, showed 7% of the initial residues. After the second lees distillation, the obtained product showed an alcoholic content of 81.2% and no residues of quinoxyfen (<0.01 mg/kg).     

Levels of stilbene oligomers and astilbin in French varietal wines and in grapes during noble rot development

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to have cancer chemopreventive activity and to protect lipoproteins from oxidative damage. A method for the direct determination of stilbene oligomers (viniferin and pallidol) as well as astilbin in different types of wine using high-performance liquid chromatography with UV detection is described. In a survey of 21 commercial wines from the south of France, levels of pallidol and viniferin are reported for the first time in different types of wines. Viniferin was found to be present only in red and botrytized sweet white wines with levels between 0.1 and 1.63 mg/L; pallidol was not found in dry and sweet white wines but only in wines made by maceration with stems, with levels between 0.38 and 2.22 mg/L. Highest levels of astilbin were found in Egiodola (15.13 mg/L), Merlot (11.61 mg/L), and Cabernet Sauvignon (8.24 mg/L) for red wines and in Sauvignon (5.04 mg/L) for white varietal wines. Astilbin levels are highest for recent vintages, but pallidol is not found in older vintages. During noble rot development in Sauvignon or Sémillon grapes from the Sauternes area, levels of trans-astringin, trans-resveratrol, trans-piceid, and pallidol are quite low (<0.5 mg/kg of grapes). Viniferin and astilbin levels become optimum at 2 and 30 mg/kg, respectively, during spot grape and speckle grape stages.     

GC-ITMS determination and degradation of captan during winemaking

Captan and its metabolite tetrahydrophthalimide (THPI) were determined in grapes, must, and wine by GC-ITMS. Pesticides were extracted with acetone/petroleum ether (50:50 v/v). Because of the high selectivity of the ITMS detector, no interferent was found and cleanup was not necessary. Recoveries from fortified grapes, must, and wines ranged between 90 and 113% with a maximum coefficient of variation of 11%. Limits of quantitation were 0.01 mg/kg for both compounds. In model systems, captan and its metabolites, THPI, cis-4-cyclohexene-1,2-dicarboxylic acid, and 1,2,3,6-tetrahydrophthalamic acid, were determined by HPLC. The degradation of captan during winemaking was studied. Captan degraded in must, giving 100% THPI, and at the end of fermentation, only THPI was found in wine. The degradation of captan to THPI was due to the acidity in must and wine. This metabolite was present at low levels on grapes, and, unlike captan, it had no negative effect on the fermentative process. Model systems showed that the mechanism of disappearance of captan in grapes was due to photodegradation and codistillation.     

Gas chromatographic determination of fenpropimorph residues in citrus fruit

A rapid gas chromatographic method for determining fenpropimorph residues in citrus fruit is reported. The fungicide is extracted with hexane after pH adjustment of the fruit homogenate. A short liquid-liquid partitioning process is performed before gas chromatography on an OV-17 column with nitrogen-phosphorus specific detection. The limit of detection of the method was 0.01 mg/kg, based on a 25 g sample. Recovery was always higher than 70%. Fenpropimorph residues in "Washington Navel" oranges and "Hernandina" clementine fruits dipped in a 1500 mg/L fungicide solution were determined. The fungicide remains mainly in the peel, with levels less than 0.1 mg/kg in the pulp. Fungicide residues in the peel decrease during storage, mainly in Washington Navel peel, where values decreased from 5.2 to 2.8 mg/kg.     

Evolution of chlorpyrifos, fenarimol, metalaxyl, penconazole, and vinclozolin in red wines elaborated by carbonic maceration of Monastrell grapes

The influence of the different steps involved in the wine-making process on the disappearance of chlorpyrifos, fenarimol, metalaxyl, penconazole, and vinclozolin in red wines elaborated by carbonic maceration of Monastrell grapes was studied. The initial levels of the residues in grapes ranged from 0.28 mg/kg (penconazole) to 1 mg/kg (chlorpyrifos). Ten days after the beginning of maceration, the compound that had decreased least was chlorpyrifos (83% of initial value remaining), whereas metalaxyl, the least persistent of the residues, had decreased to 49% of its initial value. In the free-run juice, on the other hand, the highest percentage remaining corresponded to metalaxyl (10%) and the lowest to chlorpyrifos (0. 1%). After pressing, the percentages of initial values eliminated in pomace varied from 82.7% for chlorpyrifos to 17.7% for metalaxyl, whereas in the press juice the opposite was the case (37% metalaxyl and 2% chlorpyrifos remaining). In finished wine, there were residues of all the pesticides, with the exception of chlorpyrifos, metalaxyl (21%) being the most persistent. The percentages eliminated in the lees varied from 1.5 to 2.5% of the initial value.     

Effect of pesticide residues on the aromatic composition of red wines.

The influence of pesticide residues on the aromatic composition (major and minor volatiles) of red wines made from Vitis vinifera (Monastrell var.) was studied by comparing the concentration of aromas in wines made from grapes subjected (or not) to phytosanitary treatment with chlorpyrifos, fenarimol, mancozeb, metalaxyl, penconazole, and vinclozolin, according to the agricultural practice of the area. The analytical determination of the major volatiles was made by gas chromatography using a flame ionization detector, while the minor volatiles were determined by adsorption-thermal desorption gas chromatography using a mass selective detector. There were significant differences between the ethyl acetate, methanol, isobutanol, and diethylacetal levels of the control wine and that containing chlorpyrifos residues, although only the ethyl acetate exceeded the olfactory threshold. With regard to the minor volatiles, significant differences were detected in the concentrations of some esters, aldehydes, and acids. However, only isoamyl acetate exceeded the olfactory threshold in wines containing residues of chlorpyrifos, fenarimol, and vinclozolin.     

凉州灌区酿酒葡萄氮肥施用研究

[目的]通过田间试验,研究酿酒葡萄对不同氮肥施用量及施用深度的响应,为甘肃省凉州灌区酿酒葡萄氮肥合理施用提供依据。[方法]在凉州区设置酿酒葡萄氮肥施用量及施用深度试验,研究不同氮肥施用量及施用深度对酿酒葡萄产量、收获期果实、叶片和叶柄含氮量及收获期和第2a萌芽期0—200cm土层硝态氮含量的影响。[结果]10和30cm施肥深度之间酿酒葡萄产量、收获期果实、叶片和叶柄含氮量及收获期和第2a萌芽期0—200cm土层硝态氮含量差异不显著。氮肥施用量对酿酒葡萄产量和叶柄含氮量的影响达到显著水平,对果实和叶片含氮量的影响不明显,其中高氮(300kg/hm~2)和中氮(240kg/hm~2)处理之间酿酒葡萄产量、果实含氮量、叶片含氮量、叶柄含氮量差异不明显,但是高氮和中氮处理与低氮(180kg/hm~2)处理相比,产量增加28.6%和24.1%,叶片含氮量增加17.4%和11.3%,叶柄含氮量增加了40.7%和33.0%,而对于收获期和第2a萌芽期0—200cm土层硝态氮含量,高氮处理相对于中氮和低氮处理增加了53.8%,94.4%和41.8%,76.1%,氮肥施用量和施用深度的交互效应,仅叶片含氮量达到显著水平。[结论]受土壤质地和传统沟灌影响,氮肥施用深度对酿酒葡萄影响效果不明显,240kg/hm~2为酿酒葡萄较为合适的氮肥施用量,但氮素也存在损失风险。所以,凉州灌区酿酒葡萄合理施肥应该和灌水方式进行结合来确定合理的施肥量和施肥方式。     

Incidence of fumonisin B(2) production by Aspergillus niger in Portuguese wine regions

Fumonisin B(2) (FB(2)) was recently found to be produced by Aspergillus niger . When grape-derived products were subsequently analyzed, FB(2) contamination was found in raisins, must, and wine. This study evaluated 681 strains of black aspergilli species isolated from Portuguese wine grapes for FB(2) production when grown on Czapek yeast agar. FB(2) was not detected in Aspergillus carbonarius (n = 75) or Aspergillus ibericus (n = 9) strains, but it was detected in 176 (29%) of the strains belonging to A. niger aggregate (n = 597). The amount of FB(2) produced by these strains ranged from 0.003 to 6.0 mg/kg with a mean of 0.66 mg/kg. The Alentejo region had the lowest percentage (10%) of fumonisinogenic strains, whereas the Douro region had the highest percentage of fumonisinogenic strains (38%). Only 10 strains were found to produce FB(2) and ochratoxin A simultaneously.     

Anthocyanin quantification and radical scavenging capacity of Concord, Norton, and Marechal Foch grapes and wines

The anthocyanin content and the radical scavenging capacity of three non-Vitis vinifera grapes (Marechal Foch, Norton, and Concord varieties) were determined. Analyses of anthocyanins in the skin (S) and wine (W) of these grape varieties were performed by spectrophotometry, HPLC with electrochemical detection, and matrix-assisted laser desorption ionization (MALDI). The total anthocyanin contents of S samples were 258 +/- 37 mg/100 g of wet weight for Foch, 888 +/- 78 mg/100 g for Norton, and 326 +/- 5.9 mg/100 g for Concord grapes. The malvidin 3,5-diglucoside content quantified by HPLC indicated that Norton S had the highest amount of the compound (327 +/- 110 mg/100 g). The MALDI mass spectrometric analysis indicated an abundance of malvidin glucosides in W of Foch grapes and in S and W of Norton grapes and of cyanidin aglycon in S and W of Concord grapes. S samples were subjected to a radical scavenging capacity test using the 2,2-diphenyl-1-picrylhydrazyl radical and compared to Trolox. The radical scavenging capacity for Foch S was 0.78 mM Trolox equiv, that of Concord S, 0.80 Trolox equiv, and that of Norton S was highest at 0.95 Trolox equiv. The higher concentrations of malvidin 3,5-diglucoside in S of grape varieties were associated with greater radical scavenging capacity.     

Comparison of cardioprotective abilities between the flesh and skin of grapes

Recent studies have documented that grapes and grape juices are equally cardioprotective as red wine. The existing reports implicate that the skin and seeds of the grapes containing polyphenolic antioxidants are instrumental for the cardioprotective properties of grapes. The present study examines if the flesh of grapes also possesses any cardioprotective abilities. Three groups of randomly selected rats were fed, water only (control), flesh of the grapes (2.5 mg/kg b. wt.) or the skins (2.5 mg/kg b. wt.) for 30 days. At the end of the 30 days, isolated perfused hearts were made ischemic for 30 min followed by 2 h of reperfusion in the working mode. The results demonstrated that both flesh and skin of the grapes could protect the hearts from ischemic reperfusion injury as evidenced by improved postischemic ventricular recovery and reduced myocardial infarct size. High performance liquid chromatography (HPLC) revealed that skin and flesh contained comparative amounts of glucose, fructose, tartaric acid, malic acid, shikimic acid, and trans-caftaric acid. In addition, the flesh contained reduced amounts (compared to skin) of cis-coutaric, trans-coutaric, caffeic, p-coumaric, cinnamics, and catechin/epicatechin. Total polyphenolic index was also lower in flesh compared to skin. The anthocyanins were present exclusively in the skin. Electron paramagnetic resonance (EPR) spectrometry of hydroxy radicals indicated that both flesh and skins possessed equal amount of ROS scavenging activities. Total malonaldehyde content in the heart was reduced comparatively with either flesh or skin. The results indicate for the first time that the flesh of grapes are equally cardioprotective as skin, and antioxidant potential of skin and flesh of grapes are comparable with each other despite of the fact that flesh does not possess any anthocyanin activities.     

Determination of stilbenes (delta-viniferin, trans-astringin, trans-piceid, cis- and trans-resveratrol, epsilon-viniferin) in Brazilian wines

Phenolics from grapes and wines can play a role against oxidation and development of atherosclerosis. Stilbenes have been shown to protect lipoproteins from oxidative damage and to have cancer chemopreventive activity. We describe a method for the direct determination of stilbenes in several red wines using high-performance liquid chromatography with UV detection. In a survey of 12 commercial wines from the south of Brazil (Rio Grande del Sul), levels of delta-viniferin are reported for the first time in different varieties of red wines. Brazilian red wine contains trans-astringin, trans-piceid, trans-resveratrol, cis-resveratrol (in high quantity: 5 times more than the trans form), epsilon-viniferin, and a compound isolated for the first time in wine, trans-delta-viniferin. Isolation and identification of delta-viniferin was achieved by NMR after extraction and fractionation of red wine phenolics. delta-Viniferin contributes, as well as cis-resveratrol and trans-piceid, to a significant proportion of stilbenes in wine dietary intake, particularly with Merlot varieties containing an average level of 10 mg/L for delta-viniferin, 15 mg/L for cis-resveratrol, and 13 mg/L for trans-piceid. The total stilbene intake from wine origin was estimated for the Brazilian population as 5.3 mg/day per person (on the basis of a regular wine consumption of 160 mL/day). delta-Viniferin can contribute to around 20% of total stilbenes in wine (average of 6.4 mg/L in red Brazilian wines). It would be important in the future to investigate the origins of the differences in wine stilbene levels in relation to the vine varieties, and the bioavailability of the newly extracted stilbene delta-viniferin in plasma after consumption of different types of wines.     

Gas chromatographic determination of N-nitrosamines in beverages following automatic solid-phase extraction

A semiautomatic method for the determination of seven N-nitrosamines in beverages by gas chromatography with nitrogen-phosphorus detection is proposed. Beverage samples are aspirated into a solid-phase extraction module for preconcentration and cleanup. The influence of the experimental conditions was examined by using various sorbents among which LiChrolut EN was found to provide quantitative elution and the highest preconcentration factors of all. The proposed method is sensitive, with limits of detection between 7 and 33 ng/kg, and precise, with relative standard deviations from 4.3% to 6.0%. The recoveries of N-nitrosamines from beverage samples spiked with 0.5 or 1 microg/kg concentrations of these compounds ranged from 95% to 102%. The method was successfully applied to the determination of residues of the studied N-nitrosamines in beverages including beer, wine, liquor, whisky, cognac, rum, vodka, grape juice, cider, tonic water, and soft drinks. The analytes were only detected in beer samples, positives being confirmed by gas chromatography coupled with impact ionization mass spectrometry.     

Determination of free proline and monosaccharides in wine samples by high-performance anion-exchange chromatography with pulsed amperometric detection (HPAEC-PAD)

A sensitive and selective analytical method for the simultaneous separation and quantitative determination of proline and free monosaccharides in wine samples by high-performance anion-exchange chromatography coupled with pulsed amperometric detection is described. Under optimized experimental conditions, a complete separation was obtained in less than 30 min, using an isocratic elution with 10 mM NaOH and 1 mM Ba(OAc)(2). No postcolumn addition of strong bases to the eluent for enhancing detection sensitivity was needed. Upon 25-fold sample dilution and purification to avoid interference of tannins, pigments, and phenolic compounds, the fingerprinting of common monosaccharides (i.e., arabinose, glucose, fructose, galactose, and xylose) and proline in wines, musts, and vinegars can be easily accomplished. The method allows high recovery and satisfies the necessary requirements for accuracy, repeatability, and sensitivity. Values obtained for proline content ranged from 470 to 1190 mg/L in "Aglianico" red wines (mean value, 870 +/- 192 mg/L, n = 21) and from 168 to 286 mg/L in white wines (mean value, 208 +/- 32 mg/L, n = 11). Lower levels were found in musts of red and white grapes, 550 and 87 mg/L, respectively. The lowest content of proline, ca. 10 mg/L, was found both in white and red vinegars.     

Stilbene levels in grape cane of different cultivars in southern Chile: determination by HPLC-DAD-MS/MS method

Health benefits of trans-resveratrol and other stilbenes in grapes, must, and wine have been pointed out by numerous authors. Less attention has been paid to the presence of stilbene derivatives in viticultural residues, such as grape canes. The present work reports the first results of a systematic study of stilbene levels in different grape varieties and cultivation areas in Chile, to evaluate their potential as an alternative source of bioactive stilbenes. In all cane samples, the predominant stilbene is trans-resveratrol, followed by ε-viniferin and piceatannol. In canes of Pinot noir up to 5590 ± 172 mg kg(-1) of trans-resveratrol and up to 6915 ± 175 mg kg(-1) of total stilbenes were detected. The observed concentrations of stilbenes in canes of Pinot noir from southern Chile until now are higher than those reported previously for this red variety. However, the highest concentration of total stilbenes observed in the analyzed samples was in the canes of white variety Gewürztraminer with 7857 ± 498 mg kg(-1). Preliminary results indicate that these levels can evolve if canes are left for some months on the vineyard after pruning, observing an increase during the first 2 months and a decrease after this period.     

Field trials to determine residues of chlozolinate in table grapes

Chlozolinate (Serinal) is a dicarboximide fungicide used in southern European countries principally on grapes. Maximum residue levels have not yet been set by FAO/WHO and are under evaluation in the EU. Field trials have been carried out in Greece on two varieties of table grapes (Cardinal and Victoria) during two consecutive years to assess residues remaining after application according to good agricultural practice. Analysis using a multiresidue method with gas chromatography (ECD) showed that the parent compound decays with a first-order rate constant of 0.057 +/- 0.011 day(-)(1) and that residues had fallen below the proposed MRL of 5 mg/kg in all samples by 21 days postapplication (the proposed PHI). The contribution of the main metabolite, S1, to the total residue is generally <20%. Washing removes a substantial amount (up to 80%) of chlozolinate, which appears to be nonsystemic on grapes, thus reducing real consumer exposure to this pesticide.     

Determination of 3-alkyl-2-methoxypyrazines in lady beetle-infested wine by solid-phase microextraction headspace sampling

This study determined the concentration of 3-alkyl-2-methoxypyrazines in Frontenac and Leon Millot wines made from grapes that were naturally or artificially infested with the multicolored Asian lady beetle, Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae). Headspace sampling with solid-phase microextraction (SPME) and gas chromatography (GC) was used for the quantification of 3-isopropyl-2-methoxypyrazine (IPMP), 3- sec-butyl-2-methoxypyrazine (SBMP), and 3-isobutyl-2-methoxypyrazine (IBMP). The resulting method parameters included linearity (r2 > 0.98), limit of detection (>0.25 ng/L), relative standard deviation (<20%), and recovery (75-125%). IPMP concentrations in wine were not significantly different among the levels of natural or artificial infestations of H. axyridis. SBMP was found only in wine artificially infested with H. axyridis. IBMP was found in wine artificially infested with H. axyridis and in Frontenac wine, but not in Leon Millot. The consequences of these results for future research in the contamination of wine with H. axyridis are discussed.