Anthocyanin composition of Cabernet Sauvignon and Tempranillo grapes at different stages of ripening

Changes in anthocyanins during ripening of Cabernet Sauvignon and Tempranillo grapes were studied over a three year period. The accumulation of anthocyanins showed variations during ripening, especially during the first three weeks after veraison, and the accumulation pattern of those molecules changed only slightly from one year to another. On the other hand, the percentages of the different anthocyanins studied were different for each cultivar, and some changes were observed in both cultivars depending on the weather conditions of the growing season. In warm years the percentages of primitive anthocyanins (delphinidin 3-O-glucoside and petunidin 3-O-glucoside) were slightly lower than in a relatively cool year. Nevertheless, the anthocyanin fingerprints of Cabernet Sauvignon and Tempranillo grapes seem to be rather stable during ripening, despite the sugar content of the grapes.     

Influence of copper on the adsorption and desorption of paraquat, diquat, and difenzoquat in vineyard acid soils

Retention of the cationic herbicides paraquat (PQ), diquat (DQ), and difenzoquat (DFQ) in two vineyard soils with a different management history and retention capacity was examined. The influence of copper on the ability of the soils to retain the herbicides was determined by comparing the results of adsorption and desorption tests on untreated and Cu-enriched soil samples, and also on soils that were previously treated with EDTA to extract native copper. The three herbicides were strongly adsorbed by both soils. Soil 1 exhibited linear adsorption isotherms for PQ and DFQ with partition coefficients, KD, of 1.28 x 103 and 1.37 x 103 L kg-1, respectively, and a Freundlich-type isotherm for DQ with a linearized partition coefficient, KD*, of 1.01 x 103 L kg-1. On the other hand, soil 2 exhibited curved isotherms and smaller KD* values (viz. 106, 418, and 28 L kg-1 for PQ, DQ, and DFQ, respectively). Using EDTA to extract copper from the soils released new sites for the herbicides to bind. The three herbicides exhibited strong hysteresis in the adsorption-desorption process. Extracting copper decreased the percent desorption of PQ and DQ; on the other hand, it decreased the affinity of DFQ for the resulting vacant adsorption sites. Similarly, competitive adsorption tests with copper and the herbicides revealed that the metal was only capable of displacing DFQ from adsorption sites. The behavior of this herbicide in the soils was consistent with a specific adsorption model. The disparate behavior of the two soils toward the herbicides was a result of the adsorption sites in soil 1 being less extensively occupied than those of soil 2 in the adsorption tests. The effect of copper on the adsorption of DFQ in the two soils was acceptably reproduced by an adsorption model involving Coulombic and specific sorption with competition from the metal.     

Dynamics of pesticides in potato crops

This study investigated the behavior of pesticides commonly used on potato in a part of northwestern Spain with a large area devoted to this crop. Experimental potato plots were treated with commercial formulations of two insecticides, a nematicide, a herbicide, and a combination of two fungicides, and the concentrations of the active ingredients were monitored throughout the growing season in the 0-1 and 1-15 cm soil layers, in water dripping off the potato plants, and in the potatoes themselves. The technique used for pesticide determination was gas chromatography with mass selective detection. For potato analyses, pesticide extraction was optimized. The only pesticide ever detected in potato tubers was metalaxyl, the concentration of which never exceeded half the maximum residual limit even when it was applied several times more often than is officially recommended for potato crops. Metalaxyl was also the only pesticide detected in wash-off, apparently due to its being more soluble in water than the other pesticides applied to the growing plants. A mathematical model of pesticide transport in soil was fitted to the experimental data using the program HYDRUS-1D.     

Influence of film wrapping and fludioxonil application on quality of pomegranate fruit

Pomegranates are sensitive to low temperatures. When fruit are exposed to temperatures below 5–6 °C chilling injury appears as pitting of the skin, browning of the white segments separating the arils and discoloration of the arils, and husk scald, which generally is more severe at temperatures of 6–10 °C. The main objective of this work was to assess the effectiveness of individual film packaging, applied as a stand alone treatment or in combination with fludioxonil, on reducing the occurrence of husk scald, weight loss and decay. Fruit were dipped in an aqueous mixture containing 600 mg L^?1 fludioxonil, wrapped or not wrapped with a polyolephinic heat-shrinkable film and stored at 8 °C and 90% RH for 6 or 12 weeks plus one additional week of simulated shelf-life at 20 °C and 65–70% RH. Respiration rate decreased both in cold storage and at 20 °C. Ethylene production was not detected during cold storage; its rate increased upon transfer to 20 °C, but results were inconsistent. Control fruit deteriorated at a very high rate, due to excessive weight loss, skin browning and decay. Film wrapping almost completely inhibited weight loss and husk scald and preserved fruit freshness for the whole storage time. There was no statistical difference in decay incidence between wrapped and control fruit after 6 or 12 weeks of storage and after the first shelf-life, while after the second shelf-life, wrapped fruit had significantly higher decay levels. By contrast, fludioxonil, both alone and in combination with wrapping, effectively controlled mold development, resulting in 50–67% less decay than control fruit after 12 weeks at 8 °C plus one week shelf-life. Control fruit showed minor changes in nutritional compounds as well as in total polyphenols, anthocyanins and antioxidant activity, while higher losses were detected in film-wrapped fruit during storage at 20 °C.     

Partial Nitritation-Anammox Granules: Short-Term Inhibitory Effects of Seven Metals on Anammox Activity

The inhibitory effect of seven different metals on the specific anammox activity of granular biomass, collected from a single stage partial nitritation/anammox reactor, was evaluated. The concentration of each metal that led to a 50% inhibition concentration (IC₅₀) was 19.3 mg Cu⁺²/L, 26.9 mg Cr⁺²/L, 45.6 mg Pb⁺²/L, 59.1 mg Zn⁺²/L, 69.2 mg Ni⁺²/L, 174.6 mg Cd⁺²/L, and 175.8 mg Mn⁺²/L. In experiments performed with granules mechanically disintegrated (flocculent-like sludge), the IC₅₀ for Cd⁺² corresponded to a concentration of 93.1 mg Cd⁺²/L. These results indicate that the granular structure might act as a physical barrier to protect anammox bacteria from toxics. Furthermore, the presence of an external layer of ammonia oxidizing bacteria seems to mitigate the inhibitory effect of the metals, as the values of IC₅₀ obtained in this study for anammox activity were higher than those previously reported for anammox granules. Additionally, the results obtained confirmed that copper is one of the most inhibitory metals for anammox activity and revealed that chromium, scarcely studied yet, has a similar potential inhibitory effect.     

Effects of soil flooding on P transformations in soils of the Mesopotamia region,Argentina

In the Mesopotamia region (Argentina), rice is cropped on a wide range of soil types, and the response of rice to fertilizer application has been inconsistent even in soils with very low levels of available phosphorus. Phosphorus transformations in flooded soils depend on soil characteristics that may affect phosphorus availability. This study was conducted to determine which soil characteristics were related to the changes in P fractions during soil flooding. Soils were chosen from ten sites within the Mesopotamia region that are included in five different soil orders: Oxisols, Ultisols, Alfisols, Mollisols, and Vertisols. Soil phosphorus (P) was fractionated by a modified Hedley method before and after a 45 d anaerobic‐incubation period. Changes in the inorganic P extracted with resin depended on soil pH and were related to the exchangeable‐Fe concentration of soils (extracted with EDTA). Inorganic P extracted with alkaline extractants (NaHCO₃ and NaOH) increased due to soil flooding. This increase was related to the organic‐C (OC) percentage of soils (r² = 0.62, p < 0.01), and ranged from 13 to 55 mg kg^–1. Even though previous studies showed that P associated with poorly crystalline Fe played an important role in the P nutrition of flooded rice, in this study, there was no relationship between ammonium oxalate–extractable Fe and P changes in soils due to flooding. Our results suggest that in the Mesopotamia region, changes in P fractions due to soil flooding are related to soil OC, soil pH, and soluble and weakly adsorbed Fe.     

A synthetic conjugate polysaccharide vaccine against Haemophilus influenzae type b

Glycoconjugate vaccines provide effective prophylaxis against bacterial infections. To date, however, no commercial vaccine has been available in which the key carbohydrate antigens are produced synthetically. We describe the large-scale synthesis, pharmaceutical development, and clinical evaluation of a conjugate vaccine composed of a synthetic capsular polysaccharide antigen of Haemophilus influenzae type b (Hib). The vaccine was evaluated in clinical trials in Cuba and showed long-term protective antibody titers that compared favorably to licensed products prepared with the Hib polysaccharide extracted from bacteria. This demonstrates that access to synthetic complex carbohydrate-based vaccines is feasible and provides a basis for further development of similar approaches for other human pathogens.     

Analysis of grape and wine anthocyanins by HPLC-MS

The development and application of valuable analytical tools suitable for the varietal authentication of premium red wines are matters of interest in order to avoid fraud. In this study, an HPLC-MS procedure has been developed using trifluoroacetic acid as an acid modifier in the mobile phase. This method may be used as a routine method using UV-vis detection and allows the simultaneous analysis of the structural features of anthocyanins by MS under the same chromatographic conditions. Twenty different anthocyanins have been detected in 19 different samples of both grape extracts and wines. Cis and trans isomers of p-coumaryl derivatives have been identified for the first time. Important qualitative and quantitative differences among cultivars have been detected.     

Influence of winemaking practices on the concentration of rare earth elements in white wines studied by inductively coupled plasma mass spectrometry

Influence of clarification, filtration, and storage on the concentration of rare earth elements (REEs) was studied in white wines by inductively coupled plasma mass spectrometry (ICP-MS). Smooth and parallel chondrite-normalized (CN) plots were obtained for wines which have never been in contact with fining agents. Clarification and filtration generally used in white wine production were simulated in the laboratory using nontreated reference wines, and CN plots were compared before and after treatments. Clarification by bentonites yields an overall increase in REE concentrations resulting in substantially parallel CN curves well above the plots of the corresponding nontreated wines. Filtration using silicate (SiO2), on the other hand, changes the CN profile in a nonparallel manner due to a higher release of La, Ce, Pr, Nd, and Gd, more than other elements studied. Filtration with cellulose powder causes a small increase in the concentration of light REEs, while the concentrations of other elements remain basically unchanged. Storage conditions could also affect the REE pattern of wine. We found that the influence of glass is greater than that of stainless steel and wood. In addition, we report that commercially available finished white wines from the same region show highly different REE patterns depending on the winemaking practices employed.