Experimentally induced melanin-like pigmentation (thesaurismosis) related to acorn ingestion in Nero Siciliano pigs

In this study, an experimental challenge was carried out by feeding Nero Siciliano pigs with acorn to evoke melanin-like pigmentation and support the hypothesis that it is caused by ingested material. Twelve pigs were studied, 6 fed with acorns and 6 fed commercial feed. At slaughter, all the animals fed on acorns showed black discolouration of almost all lymph nodes. The lymph nodes were normal in size and shape. Histochemical tests performed on tissues allowed us to identify and differentiate the pigment. Immunohistochemical staining for macrophage markers showed macrophages containing a variable amount of melanin-like granules. Our data, and the well-known steps of melanin formation, confirm that swine enzymes could act on phenolic substances found in acorns.     

Simultaneous detection of six RNA plant viruses affecting tomato crops using a single digoxigenin-labelled polyprobe

A polyprobe for the simultaneous detection by non-isotopic molecular hybridisation has been developed to detect any of the following six viruses causing important economic losses in tomato crops: Tomato spotted wilt virus, Tomato mosaic virus, Pepino mosaic virus, Cucumber mosaic virus, Potato Y virus and Parietaria mottle virus. The polyprobe detected all six viruses with similar sensitivity to that obtained using individual riboprobes. In addition, we evaluated the possible use of the tissue-printing as a sample preparation technique applied to routine diagnosis of tomato plants with the polyprobe. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Leaf-trait responses to irrigation of the endemic fog-oasis tree Myrcianthes ferreyrae: can a fog specialist benefit from regular watering?

Myrcianthes ferreyrae is an endemic, endangered species, with a small number of individuals located only in hyperarid, fog-oases known as lomas along the Peruvian desert in southern Peru, where fog is the main source of water. Following centuries of severe deforestation, reforestation with this native species was conducted in the Atiquipa lomas, Arequipa-Perú. On five slopes, five 2-year-old seedlings were irrigated monthly with water trapped by raschel-mesh fog collectors, supplementing natural rainfall with 0, 20, 40, 60 and 80 mm month(-1) from February to August 2008. We measured plant growth, increment in basal diameter, height and five leaf traits: leaf mass area (LMA), leaf carbon isotope composition (δ(13)C), nitrogen per leaf area, total leaf carbon and stomatal density; which are indicative of the physiological changes resulting from increased water supply. Plant growth rates, estimated from the variation of either shoot basal diameter or maximum height, were highly correlated with total biomass. Only LMA and δ(13)C were higher in irrigated than in control plants, but we found no further differences among irrigation treatments. This threshold response suggests an on-off strategy fitted to exploit pulses of fog water, which are always limited in magnitude in comparison with natural rain. The absence of a differential response to increased water supply is in agreement with the low phenotypic plasticity expected in plants from very stressful environments. Our results have practical implications for reforestation projects, since irrigating with 20 mm per month is sufficient to achieve the full growth capacity of this species.     

A highly accurate, single PCR reaction for parentage assignment in Senegal sole based on eight informative microsatellite loci

From a battery of microsatellite markers (100 loci), recently identified by our group, we have selected eight for parentage assignment in Senegal sole ( Solea senegalensis ). This tool is based on microsatellite loci obtained from four genomic DNA libraries and one cDNA library. Within the eight loci (six from anonymous genomic DNA sequences and two located in expressed sequence tags of known genes), we have found, in an analysis of a reproductive broodstock, between nine and 16 alleles. The expected heterozygosity was between 0.616 and 0.860. In addition, we have optimized the polymerase chain reaction (PCR) conditions to amplify all loci simultaneously in a single multiplex PCR reaction, and we have tested three lots of male and female (five to six individuals) and three offspring (50–60 larvae each). The use of the eight microsatellite loci, the possibility of amplifying them in a single PCR reaction and the high value of the exclusion probability (0.9992) make this multiplex PCR method a unique tool for parentage assignment.
Finally, analysing one meiotic gynogenetic progeny, we have determined the relative distance of six of these loci to the centromere, and we have also found that all of them are unlinked. All these characteristics confer this tool with a high accuracy for parentage studies and genetic population analyses of Senegal sole.     

Determination of antioxidant activity of wine byproducts and its correlation with polyphenolic content

It has been demonstrated that wine and other products derived from the grape have a high antioxidant capability; as a possible consequence of this, they may have potential benefits for health. The byproducts of the winemaking process represent a source of antioxidant compounds that has been relatively unexploited to date, but that is now the subject of increasing industrial interest. This article describes an approach to the study of the antioxidant activity of grape marcs, stalks, and dregs of both white and red varieties. This activity is compared with the measurements of their content of total polyphenols and of individual polyphenolic compounds, identified and quantified by HPLC. From the results we have been able to establish a positive correlation between the antioxidant activity and the total polyphenolic content of samples, but not with specific compounds.     

The new carotenoid pigment moraxanthin is associated with toxic microalgae

The new pigment "moraxanthin" was found in natural samples from a fish mortality site in the Inland Bays of Delaware, USA. Pure cultures of the species, tentatively named Chattonella cf. verruculosa, and natural samples contained this pigment as a dominant carotenoid. The pigment, obtained from a 10 L culture of C. cf. verruculosa, was isolated and harvested by HPLC and its structure determined from MS and 1D- and 2D-NMR. The data identified this pigment as a new acylated form of vaucheriaxanthin called moraxanthin after the berry like algal cell. Its presence in pure cultures and in natural bloom samples indicates that moraxanthin is specific to C. cf. verruculosa and can be used as a marker of its presence when HPLC is used to analyze natural blooms samples.     

Determination of baseline susceptibility of European populations of Tuta absoluta (Meyrick) to indoxacarb and chlorantraniliprole using a novel dip bioassay method

BACKGROUND: Tuta absoluta(Meyrick) is one of the most serious pests of tomato recently introduced in the Mediterranean region. A novel bioassay method designed for the accurate determination of insecticide toxicity on T. absoluta (IRAC method No. 022) was validated by three different laboratories [Greece (NAGREF), Italy (UC) and Spain (UPCT)] on European populations. RESULTS: The insecticides indoxacarb and chlorantraniliprole were used as reference products. The IRAC leaf dip method is easy to perform, producing repeatable, homogeneous responses. LC₅₀ values for indoxacarb ranged between 1.8 and 17.9 mg L^?1 (NAGREF), 0.93 and 10.8 mg L^?1 (UC) and 0.20 and 0.70 mg L^?1 (UPCT), resulting in a tenfold, 12‐fold and fourfold difference between the least and most susceptible populations at each laboratory respectively. For chlorantraniliprole, LC₅₀ values ranged between 0.10 and 0.56 mg L^?1 (NAGREF), 0.23 and 1.34 mg L^?1 (UC) and 0.04 and 0.24 mg L^?1 (UPCT), resulting in a sixfold difference in all three cases. Overall, UPCT reported lower mean LC₅₀ to indoxacarb, while UC reported higher LC₅₀ to chlorantraniliprole. CONCLUSIONS: The new bioassay is reliable, providing a useful tool in the design of IRM strategies. Within each country/lab, the variability observed in the results for both indoxacarb and chlorantraniliprole can be attributed to natural variation. Future research is necessary to determine the extent to which it is possible to compare results among laboratories. Copyright © 2012 Society of Chemical Industry     

Effect of Drying on the Phenolic Content and Antioxidant Activity of Red Grape Pomace

Winemaking by-products are considered to be a rich source of bioactive compounds. Grape pomace is susceptible to microbial degradation due to the degree of residual moisture, so the drying of this pomace for conservation is considered to be an essential first step. Previous studies concerning the way in which drying affects winery by-products have produced contradictory results. In this study, a new methodology for drying grape pomace in a climatic chamber has been evaluated. Five red grape pomace varieties were dried in a climatic chamber at 40 °C and 10% relative humidity and the phenolic content and antioxidant activity of the dried and wet pomace samples were compared. The results indicate that this drying process is both feasible and beneficial because significant increases in the extractability of phenolic compounds and antioxidant activity were achieved.     

Pressurized liquid extraction of capsaicinoids from peppers

A method has been developed for the extraction of capsaicinoids from peppers by pressurized liquid extraction (PLE); these compounds are determined by reverse phase high-performance liquid chromatography (HPLC), with detection by fluorescence spectrophotometry and mass spectrometry (MS). The stability of capsaicin and dihydrocapsaicin has been studied at different temperatures (50-200 degrees C), and several extraction variables have been assayed: solvent (methanol, ethanol, and water), different percentages of water in the methanol (0-20%) and in the ethanol (0-20%), and the number of extraction cycles. The study has evaluated the repeatability (RSD < 7%) and the reproducibility (RSD < 7%) of the method. Finally, the PLE method developed has been applied to quantify the capsaicinoids present in three varieties of hot peppers cultivated in Spain, quantifying five capsaicinoids: nordihydrocapsaicin, capsaicin, dihydrocapsaicin, an isomer of dihydrocapsaicin, and homodihydrocapsaicin.     

Optimizing the process of making sweet wines to minimize the content of ochratoxin A

During the drying process of raisins, the grapes are subjected to climatic variations that can result in heavy infections of some fungal species that produce ochratoxin A (OTA), a powerful toxic metabolite, whose maximum permitted content is set by the European Union at 2.0 μg/L for grapes, wine and other drinks derived from the grape. The aim of this paper is to optimize the process of making sweet wines in order to minimize the content of ochratoxin A. The results reflect a reduction of the OTA content in grapes dried under controlled conditions in a climatic chamber up to 24% compared to those sunned in the traditional way. A decrease of the concentrations of OTA is also observed during the processes of vinification. Those wines with prefermentative maceration reached a higher OTA content than the wines without maceration, but unexpectedly were not those preferred from a sensorial point of view. In addition, the process of aging in oak casks has been shown to serve as a natural method for reducing the OTA content of these wines.