Chemical authentication of extra virgin olive oil varieties by supervised chemometric procedures.

This work has focused on discriminating extra virgin olive oils from Sabina (Lazio, Italy) by olive fruit variety (cultivar). A set of oils from five of the most widespread cultivars (Carboncella, Frantoio, Leccino, Moraiolo, and Pendolino) in this geographical area was analyzed for chemical composition using only the Official Analytical Methods, recognized for the quality control and commercial classification of this product. The obtained data set was converted into a computer-compatible format, and principal component analysis (PCA) and a method based on the Fisher F ratio were used to reduce the number of variables without a significant loss of chemical information. Then, to differentiate these samples, two supervised chemometric procedures were applied to process the experimental data: linear discriminant analysis (LDA) and artificial neural network (ANN) using the back-propagation algorithm. It was found that both of these techniques were able to generalize and correctly predict all of the samples in the test set. However, these results were obtained using 10 variables for LDA and 6 (the major fatty acid percentages, determined by a single gas chromatogram) for ANN, which, in this case, appears to provide a better prediction ability and a simpler chemical analysis. Finally, it is pointed out that, to achieve the correct authentication of all samples, the selected training set must be representative of the whole data set.     

The red soils, their origin, properties, use and management in Greece

Red soils in Greece are distributed throughout the country, but they occur more frequently in the southern provinces and constitute important soil resources supporting several land utilization types. They can be grouped into two categories: the autochthonous and the allochthonous. The former soils are found on hard limestone and on basic igneous rocks in sloping mountainous or hilly landscapes. Moreover, they can be found on mica schists and gneisses in locations adjacent to marble or calcareous mica schists.Allochthonous red soils are wide-spread on late Tertiary and Pleistocene surfaces in the lowlands. Many of these deep deposits have red strata, a few decimeters to several meters thick, or red-colored and fine-textured layers interbedded with light colored deposits of marl, or conglomerates and also with thick strata enriched with calcareous concretions. They are distributed in the thermo- and meso-mediterranean bioclimatic zones. These sites have a common feature, the gently sloping terrain that ensures efficient drainage.There are some differences in chemical and physical properties and in the clay mineralogy of the two groups of Greek red soils. Palygorskite is present in some soils developed on basic rocks; the clay minerals of the allochthonous soils on Pleistocene and late Pliocene seems to be mixed with micas in significant amounts.Soil forming factors required for the formation of red soils are: (a) parent material containing iron-bearing minerals, and rich in bases, (b) slope gradients and/or water permeabilities of the bed-rock securing excessive drainage and (c) vegetation cover that does not produce high amounts of, and deeply distributed organic matter.The allochthonous red soils have likely inherited their color from their parent materials that were transported from the originally formed residual soils on hard limestone. The soils retain the red color in the thermo-mediterranean zone only on sloping terrains. The soils on these landscapes are frequently stratified.The Greek red soils belong to the great groups of: Rhodoxeralfs, Palexeralfs, Xerochrepts, Orthents. Large portions of the allochthonous soils have been desertified or have been severely degraded and their extensive exploitation is not recommended.Soil management practices applied in the allochthonous soils include erosion control, preservation of organic matter, minimum tillage, split application of nitrogen using non-acidifying fertilizers, irrigation, soil water conservation and sheltered agriculture.     

Chemical response of hardwood oligosaccharides as a statistical function of isolation protocol

Hardwoods contain a substantial amount of hemicellulose-type oligosaccharides, the chemical structures of which are typically categorized in the xylan saccharide class. The efficient and selective isolation of these hemicelluloses is regarded as one of the most critical obstacles to overcome for their eventual biomaterial and bioenergy utilization. Therefore, the objective of the current work was to perform a fundamental exploration of the function of extraction pH, temperature, and time on the final chemical properties of the extracted hemicelluloses. The extraction chemistries employed varied pH and showed that acidic conditions provided a higher extractive yield versus alkaline conditions. An alkaline environment gave higher yields than an acidic environment and also resulted in much higher lignin removal from wood, especially at high temperature. In general, control of the pH chemistry leads to a change in the carboxylic acid groups present in the extracts. When the extraction pH changed from acidic to alkaline, the total carboxylic acid group content in the hemicelluloses removed significantly increased due to more acetic acid group hydrolysis and increased lignin degradation.     

Monolithic supports for the characterization of commercial maize products based on their chromatographic profile. Application of experimental design and classification techniques

Modern analytical techniques based on the use of RP-HPLC with monolithic stationary phases and the application of experimental design and classification tools have been applied to the analysis of maize proteins. Solubilization conditions of maize proteins and separation conditions (temperature, detection wavelength, type and concentration of ion-pairing agent, and gradient) were optimized. The elution gradient was optimized by the application of experimental design techniques. The optimized method consisted of a linear binary gradient of water/acetonitrile/0.1% trifluoroacetic acid in three steps at a flow rate of 3 mL/min with a column temperature of 35 degrees C and UV detection at 280 nm. The developed method enabled the separation of maize proteins in an analysis time close to 8 min. Moreover, this is the first time that commercial maize products have been characterized by the use of multivariate classification techniques.     

Preliminary chemometric study on the use of honey as an environmental marker in Galicia (northwestern Spain)

Thirteen metal elements were determined in 40 honey samples from Galicia with different environmental origins: rural, urban, and industrial areas. The data set of the honey metallic profiles was studied with a double purpose: first, to make a preliminary evaluation of honey as an environmental indicator in Galicia with the aim of monitoring pollution and, second, to compare the different capabilities of diverse pattern recognition prediction procedures for modeling the environmental surrounding of the hive. A certain level of similarity for urban and industrial samples was obtained using principal component analysis and cluster analysis, whereas significant differences for urban and industrial honeys were found in relation to rural honey samples. Different classification rules to associate metal content of honeys with their environmental surrounding were obtained by chemometric pattern recognition procedures. In general, the classification methods developed by neural networks provided better results than the traditional pattern recognition procedures. The metal profiles of honey seem to provide sufficient information to enable categorization criteria for classifying samples according to their environmental surrounding. Thus, honey could be a potential pollution indicator for the Galician area.     

Infrared identification test for scopolamine as the hydrobromide.

The method of preparation of scopolamine hydrobromide affects the infrared (IR) spectrum of the product. A column chromatographic procedure is used to both isolate the drug from tablets and injections and form the hydrobromide salt. This yields reproducible IR spectra and thus constitutes an identity test for scopolamine hydrobromide.     

The Cerrado into-pieces: Habitat fragmentation as a function of landscape use in the savannas of central Brazil

Habitat fragmentation and land conversion by humans for agricultural purposes are constant threats to conservation of biodiversity in the Cerrado biome. These landscapes dominated by agricultural activities became dynamic mosaics, which are formed by different land uses. Thus, understanding how the properties of these mosaics affect species’ persistence is one urgent necessity. In this study, the landscape structure of the Cerrado in Goiás State, Central Brazil, was quantified by the use of fragmentation indices, analysed at the class level. The objective of this study was to assess if land use for crop production or for pasture produces different fragmentation patterns, which can result in different pressures for the Cerrado biodiversity. The study showed that landscapes dominated by crops are more fragmented than landscapes dominated by pastures. These crop-dominated landscapes also presented a smaller number of fragments that could maintain populations of threatened mammal species in Cerrado. Regions with more preserved natural areas are in the northeast of Goiás, where there are rough relief and soil unsuitable for agriculture. Our results indicate that croplands generate a landscape structure more damaging for the conservation of biodiversity in the Cerrado biome. Otherwise, they support the importance to preserve natural remnants, even in areas occupied by agriculture, mainly due to its potential to maintain ecosystem services, and suggest that landscapes dominated by pastures should have more current value for conservation, since they showed larger fragments.     

Chemical constituents in Baccharis dracunculifolia as the main botanical origin of southeastern Brazilian propolis

Previously, it was reported that one group of propolis (Group 12) was identified in southeastern Brazil, and the botanical origin of the propolis was Baccharis dracunculifolia resinous exudates. It was also observed that honeybee (Africanized Apis mellifera) mainly visited the leaf buds or unexpanded leaves of B. dracunculifolia but rarely expanded leaves. B. dracunculifolia is dioecious with male and female inflorescences, and RPHPLC of the ethanolic extracts of the respective male and female bud resinous exudates showed the same profiles. RPHPLC profiles of propolis G12 leaf buds and unexpanded and expanded leaves of B. dracunculifolia showed similarity, but unexpanded leaves quantitatively decreased in chemical constituents as compared with leaf buds. In the case of expanded leaves, all chemical constituents were severely decreased or disappeared. Artepillin C (3,5-diprenyl-4-hydroxycinnamic acid) was also identified in both propolis and resinous exudates, and both ethanolic extracts contained the highest concentrations of this compound as compared with the rest of the chemical constituents.     

Relationship between varietal amino acid profile of grapes and wine aromatic composition. Experiments with model solutions and chemometric study

Synthetic solutions containing amino acids, sugar, water, and yeast nutrients have been fermented by Saccharomyces cerevisiae, and the volatile composition of the fermented media has been analyzed by GC. Eleven amino acid compositions imitating the characteristic amino acid profile of 11 different grape varieties were tested. Significant differences in the levels of some important volatile compounds (ethanol, ethyl acetate, acetic acid, higher alcohols and some of their acetates, methionol, isobutyric acid, ethyl butyrate, and hexanoic and octanoic acids) were found. The levels of some of the volatile compounds are well correlated with the aromatic composition of wines made with grapes of the same varieties. A multiple linear regression study produced good models for most of the odorants for which the level was related to the must amino acid composition. Partial least-squares regression models confirm that amino acid composition explains a high proportion of the variance in the volatile composition and show that the relationship between both sets of variables is highly multivariate. According to the different models, the levels of some byproducts of fatty acid synthesis are related to threonine and serine, the level of beta-phenyletanol is closely related to the level of phenylalanine, and methionol is strongly correlated to the must methionine contents. The addition of selected amino acids to different musts confirms the previous observations.     

Chemical ecology in wheat plant-pest interactions. how the use of modern techniques and a multidisciplinary approach can throw new light on a well-known phenomenon: allelopathy

A new holistic approach on research into allelopathy was launched in the FATEALLCHEM project. The project was financed by the European Commission in the 5th Framework Programme and involved agronomists, biologists, analytical chemists, organic chemists, environmental chemists, ecotoxicologists, and modelers. Benzoxazinones from wheat (Triticum aestivum L.) were the main group of compounds studied in the project. The project showed that future assessments of an extensive use of allelopathic crops must include the development of validated analytical methods, considerations of relevant concentrations, studies on soil transformation, ecotoxicological studies on individual compounds and mixtures, evaluation on human and mammal toxicity, and joint effect studies on weeds, insects, and pathogens. The project results clearly showed the relevance of optimizing the exploitation of cereal benzoxazinones. Crop rotation is a very traditional practice, which was given less importance for decades but is now regaining its importance in agricultural practice as a means of controlling weed seed banks and soilborne diseases and pests. When using cereals as catch crops and green manure, the allelopathic properties of the cereals could now be much more extensively exploited, choosing varieties with optimal production of benzoxazinones and optimizing the time of sowing in relation to the formation of bioactive metabolites.     

The use of sewage sludge as soil amendment. The need for an ecotoxicological evaluation

Background, aim, and scope  Sewage sludge use in agriculture should be limited by the presence of metals and other persistent environmental pollutants. The present study aims to contribute for the definition of a test battery of ecotoxicological assays that allows a proper ecotoxicological characterization of sludges, providing information on their potential hazard and identified “safe” application levels. Materials and methods  Three sludges from distinct sources (urban, olive-processing, and electroplating industries) were tested using avoidance and reproduction tests with earthworms (Eisenia andrei) and springtails (Folsomia candida) and plant growth tests with turnips (Brassica rapa) and oats (Avena sativa). Different soil–sludge mixture concentrations mimicking recommended/realistic field dosages were tested. Results  Only the sludge from the electroplating industry induced an avoidance response from the earthworms (EC₅₀ = 0.4 t/ha) and collembolans (no observed effect concentration (NOEC) = 15 t/ha). This sludge was the only sludge responsible for any effect on the reproductive output of the earthworms (EC₅₀ = 7.74 t/ha). Regarding collembolans, none of the sludges tested caused any significant decrease in reproduction. In higher plant tests, the two industrial sludges were toxic, causing a decrease growth in both species. The EC₂₀ values determined for B. rapa were 20.3 and 24.2 t/ha and for A. sativa 14.7 and 16.2 t/ha for sludges from olive-processing and electroplating industries, respectively. Discussion  The metal loadings of the different test sludges could partially explain the results obtained. The toxicity of the test sludge from electroplating industry observed on the tested invertebrates and plants could be explained by the high amount of total chromium from which 22.3% was in the most toxic oxidation state—Cr(VI). However, the toxicity caused by the sludge from the olive-processing industry in the test plants could be attributed to the presence of other compounds (not measured in this study) since the metal content was not high enough to induce such an effect. The absence of toxicity showed by the urban test sludge was in agreement with its low levels of metals. Conclusions  The response of the different test organisms and end points varied according to the sludge type. The urban sludge was non-toxic whereas the sludge from the electroplating industry caused a toxic effect on almost all parameters measured (avoidance behavior of both test organisms, reproduction of earthworms, and growth of both plant species). Sludge from the olive-processing industry only caused a toxic effect on growth of both plant species. By analyzing the sensitivity of the different parameters for the most toxic sludge, it was found that avoidance and reproduction were more sensitive than plant growth, whereas plant seed germination was not sensitive at all. Recommendations and perspectives  The ecotoxicological evaluation of wastes can be used as an environmental safety control of sludge use in agriculture. A tiered approach could be adopted for this purpose, incorporating avoidance tests in the first tier (screening level) and reproduction and plant growth tests in a second tier. But more evidence aiming to define the most suitable ecotoxicological test battery for specific sludges with a different contamination profile is still needed.     

Orders in the soil classification system of Russia: Taxonomic distance as a measure of their adequate identification

Taxonomic distances between pairs of soil orders in the Russian soil classification system have been calculated using a methodology suggested for calculation of taxonomic distances between the Reference Soil Groups in the international soil classification system (WRB). Basing on the data obtained, some proposals for the development of the Russian soil classification system have been formulated. Most of the orders are characterized by considerable taxonomic distances between them, and their identification in the classification system is doubtless. Small taxonomic distances are characteristic of the following pairs of orders: organo-accumulative and structural-metamorphic soils, hydrometamorphic soils and lithozems, and cryometamorphic and eluvial soils. Therefore, criteria for defining some orders, and/or profile formulas for some soil types composing the orders may be revised. The comparison of taxonomic distances between soil orders in the Russian system and between Reference Soil Groups in the international system allows us to suggest their certain similarity.     

Carbohydrates as Chemical Constituents of Biowaste Composts and their Humic and Fulvic Acids

The decomposition of organic matter of source-separated biowaste during composting was followed during 18 months. Compost samples were fractionated into three parts: (i) hot water soluble extract (HWE) (ii) bitumen fraction and (iii) humic substances (humic acids (HA) and fulvic acids (FA)). Original compost samples and the HA and FA fractions were hydrolyzed with sulfuric acid for hexoses and pentoses. Quantitative spectrophotometric and qualitative GC/MS analyses of monosaccharides as trimethylsilyl ethers of the corresponding alditols were carried out.

During composting, the amount of HA in the organic matter of the compost increased, the amounts of HWE and bitumen decreased and the amount of the FA fraction changed only a little. Carbohydrates were found to be important constituents of biowaste composts and their HA and FA fractions. Elemental analysis (C, N and H) of compost and HA samples showed an increase in the C:H ratio and in unsaturation of compounds during composting. The decrease in the C:N ratio was marginal.

The amounts of hexoses and pentoses in original compost samples and the HA and FA fractions decreased during composting. The sugar alcohols erythritol, xylitol, L-arabitol, ribitol, L-rhamnitol, L-fucitol, D-mannitol, D-glucitol and galactitol were identified in both the HA and FA fractions. 2-Deoxy-D-erythro-pentitol was identified in one HA fraction and inositol in two FA fractions. An analysis of gas chromatographic data for relative abundances showed that, in every sample except one and in every stage of composting D-glucitol was the main sugar alcohol. In general, the relative amount of D-glucitol decreased during composting, while the relative amounts of all other sugar alcohols increased.

As chemical indicators of compost maturity, carbohydrates would appear to be a important group of compounds. Most informative as a general indicator would be the ratio of the amount of HA to the amount of organic matter in the total compost samples.

According to our studies, the carbohydrates in composts are covalently bound to the structures of FA and HA. Carbohydrate determination clearly deserves more attention in the structural elucidation of FA and HA.     

Study of the phenolic profile of cider apple cultivars at maturity by multivariate techniques.

Phenolic compounds in 46 Spanish cider apple varieties were determined by RP-HPLC with direct injection. Several pattern recognition procedures, including principal component analysis (PCA), linear discriminant analysis (LDA), and partial least squares (PLS-1), were applied to the data in an attempt to classify the samples into bitter and nonbitter categories. Reliable decision rules were obtained by both LDA and PLS-1. LDA achieved 91.3 and 85.7% correct classification respectively, for internal and external evaluation of the model.     

The functions of wildlife and their possible use for deriving site selection components

The beneficial uses or functions of wildlife are numerous. In agriculture these include not only the cropping of species growing in the wild but also their potential for future cultivation and role in such processes as crop pollination and biological control of pests. Wild animals are used in medicine for essential research; wild plants provide a source of drugs, and wild places can help to relieve the tension and stress associated with modern living. Wildlife is also a sensitive indicator of environmental change. Furthermore, research and education in the environmental sciences rely on the conservation of natural and semi-natural areas. These areas and the species which inhabit them have considerable aesthetic value and have inspired many great works of art. Finally, there is a moral argument that all species have the right to exist, and that the options made possible by the presence of wildlife should be left for future generations to use. Each of these functions is discussed in detail.Sixteen components should be taken into consideration when evaluating an area for wildlife conservation. A possible approach to weighting these components is outlined.     

The use of RAPD markers to facilitate the identification of Oryza species within a germplasm collection

RAPD analysis was carried out using 93 accessions held within the Oryza collection in the Genetic Resource Center at IRRI. These accessions had been designated as O. meridionalis, O. glumaepatula, O. nivara or O. rufipogon on the basis of the identification of the original collector although in some cases these had been subjected to subsequent taxonomic revision. Following numerical analysis of the RAPD data, we propose that five of the forty accessions designated as O. meridionalis and four of the 22 accessions designated as O. glumaepatula have been mis-identified. The relationship between accessions designated as O. nivara and O. rufipogon is complex, although it appears that some mis-identification has also occurred for these two taxa. The results indicate that RAPD technology can be used as a fast and accurate method to assist in the validation of the identification of wild Oryza species.     

Red Mud as a Chemical Stabilizer for Soil Contaminated with Toxic Metals

We performed a 2-year microcosm study to assess the effectiveness of red mud, a by-product of bauxite processing, in stabilizing contaminated mine waste and agricultural soil. Our study used red mud from a long-term disposal area in Almásfüzit?, Hungary with a pH of 9.0. A 5% (by weight) red mud addition decreased the highly mobile, water-extractable amount of Cd and Zn by 57% and 87%, respectively, in the agricultural soil and by 73% and 79%, respectively, in the mine waste. In a laboratory lysimeter study, the addition of red mud reduced the concentration of Cd and Zn in the leachate by about two third of the original. The metal content of the leachate was below the Maximum Effect Based Quality Criteria for surface water as determined by a risk assessment in the metal-contaminated area of the Toka valley near Gyöngyösoroszi, Hungary. The addition of red mud did not increase the toxicity of the treated mine waste and soil and decreased the Cd and Zn uptake of Sinapis alba test plants by 18–29%. These results indicate that red mud applied to agricultural soil has no negative effects on plants and soil microbes and decreases the amounts of mobile metals, thus indicating its value for soil remediation.