Carotenoid, chlorophyll, and chlorophyll-derived compounds in grapes and port wines

Carotenoids and chlorophyll-derived compounds in grapes and Port wines were investigated by HPLC-DAD and HPLC-DAD-MS (ESP+) analysis. A total of 13 carotenoid and chlorophyll-derived compounds are formally reported in grapes, 3 are identified for the first time, pheophytins a and b and (13Z)-beta-carotene, and 3 others remain unknown. In Port wines 19 compounds with carotenoid or chlorophyll-like structures are present, 8 still unidentified. The young wines showed higher total carotenoid content and chlorophyll-like compounds compared to aged Ports, with lutein and beta-carotene as major carotenoids. Among samples analyzed of monovarietal Vitis vinifera L. cultivar wines produced with the five most important Douro varieties, Tinta Roriz contained the highest levels of carotenoids and Touriga Franca the lowest. The forced-aging study indicated that lutein was more sensitive to temperature than beta-carotene. Additionally, aged wines showed higher ratios of beta-carotene/lutein concentrations compared to new Ports. Rates of degradation of chlorophyll derivative compounds were higher than those for carotene and lutein.     

Thiamine (vitamin B1) deficiency in germinating seeds of Phaseolus vulgaris L. exposed to soaking injury

Exogenous application of thiamine (vitamin B1) during imbibition improved germination and seedling development of bean (Phaseolus vulgaris L. cv. Lasso) seeds, which were exposed to soaking injury by submergence. Leaching of the vitamin into the incubation medium was not increased in submerged seeds. However, translocation of the thiamine reserves from the cotyledons to the seedling axis was reduced in response to soaking injury. After exogenous application of free thiamine to the seeds, thiaminedi-phosphate (TDP), which is the physiologically active coenzyme form of thiamine, accumulated in the seedling axis of submerged seeds, suggesting an increased demand for thiamine-dependent metabolic reactions in these tissues. Limited oxygen supply of the seeds during the soaking period induces a shift from respiration to fermentation of carbohydrates. Neither thiamine-dependent ethanolic fermentation, nor ATP production or adenylate energy charge (AEC) of the seedling axis were affected by exogenous thiamine application, suggesting that there is no limitation of thiamine-dependent reactions in the energy metabolism of the seedlings. Thus the physiological mechanisms improving germination and seedling development of submerged seeds in response to thiamine seed treatment are still not clear.     

Interaction of contaminated sediment from a salt marsh with estuarine water: evaluation by leaching and ecotoxicity assays and salts from leachate evaporation

Purpose

Wastes from a former Portuguese steel plant were deposited between 1961 and 2001 on the riverbank of a tributary of the Tagus River creating a landfill connected to the river, posing a potential contamination risk to the Tagus estuary ecosystem. This study aims to assess the transfer of chemical elements from contaminated sediments to the estuarine water from cycles of sediment leaching so as to evaluate the ecotoxicity of the leachates, and to analyze the solid phases crystallized from those leachates.

Materials and methods

Landfill sediment and estuarine water samples were collected during low tide. Sediment samples were analyzed for pH, electric conductivity (EC), C_org, NPK, and iron oxides. Leaching assays (four replicates) were done using estuarine water (200 cm³/replicate) and 1.5 kg of sediment per reactor. Each reactor was submitted to four leaching processes (0, 28, 49, and 77 days). The sediment was kept moist between leaching processes. Sediment (total (acid digestion) and available fraction (diluted organic acid extraction-Rhizo)) elemental concentrations were determined by inductively coupled plasma–instrumental neutron activation analysis (ICP/INAA). Leachates, and estuarine and sediment pore waters were analyzed for metals/metalloids by ICP/mass spectrometry (MS) and carbonates/sulfate/chloride by standard methodologies. Ecotoxicity assays were performed in leachates and estuarine and pore waters using Artemia franciscana and Brachionus plicatillis. Aliquots of the leachates were evaporated to complete dryness (23–25 °C) and crystals analyzed by X-ray powder diffraction (XRD).

Results and discussion

Sediment with pH?=?8 and high EC and C_org was contaminated with As, Cd, Cr, Cu, Pb, and Zn. The element concentrations in the available fraction of the sediment were low compared to the sediment total concentrations (<1 % for Rhizo extraction). The concentrations of potentially hazardous elements in the estuarine water were relatively low, except for Cd. Concentrations of hazardous elements in the leachates were very low. Calcium, K, Mg, Na, and chloride concentrations were high but did not vary significantly among the four leaching experiments. Total concentrations of carbonate were much higher in leachates than in estuarine water. Both estuarine water and leachates showed negligible toxicity. Crystals identified in the solids obtained from the leachates by evaporation were halite, anhydrite, epsomite, dolomite, and polyhalite.

Conclusions

The sediment showed the capacity to retain the majority of the potentially hazardous chemical elements. Remobilization of chemical elements from sediment by leaching was essentially negligible. The variation of total concentrations of Ca, carbonate, and sulfate in leachates indicates that the sediment contained reactive sulfides. Due to its composition, the sediment seems to be a dynamic system of pollution control, which should not be disturbed.

     

Purification and partial characterization of lipoxygenase from desert truffle (Terfezia claveryi Chatin) ascocarps

A lipoxygenase from Terfezia claveryi Chatin ascocarp, a mycorrhizal hypogeous fungus, is described for the first time. The higher proportion of PUFA in T. claveryi ascocarps makes lipid rancidity the main factor limiting its storage life. Thus, the studies on LOX from T. claveryi are important because this enzyme, among other roles, may be involved in an alteration of lipids leading to consumer rejection. The enzyme has been purified to apparent homogeneity by phase partitioning in the presence of Triton X-114, followed by two steps of cation-exchange chromatography. The purified T. claveryi LOX preparation consisted of a single major band with an apparent molecular mass of 66 kDa after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzymic activity exhibited a strong specificity toward linoleic and linolenic acids as substrates, while only 32% activity was observed using gamma-linolenic acid. The pH optimum of this enzyme was pH 7.0. When the enzyme reacted with linoleic acid, it produced a single peak, which comigrated with standard 13-hydroperoxy-octadecadienoic acid; 13-hydroperoxy-octadecatrienoic acid was produced during the reaction with linolenic acid.     

Novel application of square-wave adsorptive-stripping voltammetry for the determination of xanthohumol in spent hops

This paper reports the development of a novel electrochemical assay for xanthohumol (XN) by square-wave adsorptive-stripping voltammetry (SWAdSV) with a hanging mercury drop electrode. The method showed good repeatability (CV < 2%) and linearity (between 10 and 250 μg L(-1)), as well as suitable limits of detection (2.6 μg L(-1)) and quantification (8.8 μg L(-1)). The method was applied for the quantification of this compound in spent hops, and the results obtained were compared with the HPLC-UV method. XN contents determined by the SWAdSV method were 16 ± 1 and 100 ± 4 μg L(-1) for aqueous and methanolic extracts, respectively. The developed new methodology considerably reduces the analysis time, approximately from 25 min (HPLC-UV method) to 7 min, enabling a high sample throughput. In addition, the detection and quantification limits were approximately 5-fold lower than those obtained with the chromatographic method.     

The role of border areas for dendrochronological investigations on catastrophic snow avalanches: A case study from the Italian Alps

Snow avalanches are common in mountain environments, sometimes affecting inhabited areas and infrastructures (e.g. roads, bridges, and ski slopes). Their study is widespread and involves the use of a variety of different techniques, including dendrochronological methods. The aim of such investigations is principally to date past events, but also to detect variation in avalanche frequency as well as their spatial distribution. Trees affected by snow avalanches generally have scars, tilted trunks and broken branches, which allow past events to be dated to within a year. In this work tree rings were used to investigate a disruptive snow avalanche which occurred in 2001 in Val Mala in the Italian Alps. The event almost completely removed forest along the flow path, while the snow powder component of the avalanche also impacted on the adjacent forest. Comparison of tree reaction in surviving plants along the flow path and vegetation on the border showed i) the production of reaction wood even in apparently undisturbed trees and ii) the usefulness of border plants for dating past events. Different dendroecological indicators were investigated (i.e. reaction wood, scars, traumatic resin ducts, and variations in stem eccentricity) and reaction wood is evidently concentrated from 2001 not only in damaged trees but also in adjacent plants. The potential to investigate past snow avalanches by collecting samples from trees growing in border areas is presented: in the specific case of Val Mala, vegetation bordering the flow paths reacted to produce reaction wood in 2001, in a similar manner to plants along the flow track, demonstrating their usefulness in such investigations. Their response to the 2001 event confirms the possibility of applying dendrochronological techniques to trees adjacent to the flow path, even if they appear morphologically undisturbed, and proposes to use only border areas in cases of an absence of sufficient trees along the avalanche track.     

Characterization of Sardinian cork oak (<Emphasis Type="Italic">Quercus suber</Emphasis> L.) genetic resources for economically important traits

Considering the very high socio economic value of cork oak (Quercus suber L.) in Mediterranean areas, a better knowledge of local genetic resources is necessary in order to reach a good balance between the conservation issues and the need of an efficient cork production network. In such frame, local germplasm of Q. suber from the main cork production areas of Sardinia was analysed for DNA and isozyme polymorphisms and for cork quality in relation to some environmental parameters. A total number of 24 sample stands of cork oak were selected, representing typical vegetation, sylvicultural and cork quality features within the eight identified cork growing areas in Sardinia. Considerable variation was found between cork oak stands of the different areas. Results of the principal component analysis performed on the cork quality data and environmental characters of the eight areas, showed that the first three components explain 72.2% of the variation. The major characters involved in this differentiation were cork quality characters such as dimensional recover, moisture and Mg content of the cork and also elevation of stands m a.s.l. for the first component. The second component appears to be determined by some climatic parameters (average annual temperature and average of the minimum temperatures of coldest month) and by the Fe and Zn in the cork. For the third component, major characters involved in differentiation are average annual rainfall, bark thickness and Ca content in the cork.     

A microwave tomographic system for wood characterization in the forest products industry

Abstract

Nondestructive testing and evaluation techniques able to extract information about the internal structure of the samples under test are very important in the wood industry. Microwave imaging systems have been considered for a long time promising apparatuses for this task. In this framework, approaches exploiting the full scattering phenomena for creating images of the distributions of the dielectric properties of the targets have been developed in the last few years. In this paper, a prototype of microwave tomographic system is presented and several experimental validation confirming its suitability for the use in the wood and forest product industry are reported.     

Tracking leaf area index and coefficient of light extinction over the harvesting cycle of black wattle

The amount of photosynthetic radiation intercepted by a crop is a function of the incident solar radiation on the plants, the leaf area index (L _AI), and the light extinction coefficient (k). We quantified L _AI and k in stands of black wattle (Acacia mearnsii De Wild.) over a 7-year growth cycle at two locations in the state of Rio Grande do Sul, Brazil. Our study was conducted in commercial stands in agroecological regions with high densities of black wattle plantations. L _AI was calculated as the ratio between the leaf area of a tree and its planting space, and k was derived from Beer’s law. L _AI depends on the planting site and stand age. Between the two sites, the L _AI was similar over time, the amount of variation differed. Values of k depended only on stand age, with the highest average observed for stands up to 5 years old. The trend of k during the plantation cycle was inversely proportional to L _AI and was correlated with L _AI, leaf area, leaf dry mass, canopy volume, height, branches dry mass, total dry mass, and crown diameter.