Classification of pumpkin seed oils according to their species and genetic variety by attenuated total reflection Fourier-transform infrared spectroscopy

Attenuated total reflection Fourier-transform infrared spectroscopy (ATR-FTIR), followed by multivariate treatment of the spectral data, was used to classify seed oils of the genus Cucurbita (pumpkins) according to their species as C. maxima, C. pepo, and C. moschata. Also, C. moschata seed oils were classified according to their genetic variety as RG, Inivit C-88, and Inivit C-2000. Up to 23 wavelength regions were selected on the spectra, each region corresponding to a peak or shoulder. The normalized absorbance peak areas within these regions were used as predictors. Using linear discriminant analysis (LDA), an excellent resolution among all categories concerning both Cucurbita species and C. moschata varieties was achieved. The proposed method was straightforward and quick and can be easily implemented. Quality control of pumpkin seed oils is important because Cucurbita species and genetic variety are both related to the pharmaceutical properties of the oils.     

Fingerprints for main varieties of argentinean wines: terroir differentiation by inorganic, organic, and stable isotopic analyses coupled to chemometrics

Our main goal was to investigate if robust chemical fingerprints could be developed for three Argentinean red wines based on organic, inorganic, and isotopic patterns, in relation to the regional soil composition. Soils and wines from three regions (Mendoza, San Juan, and Co?rdoba) and three varieties (Cabernet Sauvignon, Malbec, and Syrah) were collected. The phenolic profile was determined by HPLC-MS/MS and multielemental composition by ICP-MS; (87)Sr/(86)Sr and δ(13)C were determined by TIMS and IRMS, respectively. Chemometrics allowed robust differentiation between regions, wine varieties, and the same variety from different regions. Among phenolic compounds, resveratrol concentration was the most useful marker for wine differentiation, whereas Mg, K/Rb, Ca/Sr, and (87)Sr/(86)Sr were the main inorganic and isotopic parameters selected. Generalized Procrustes analysis (GPA) using two studied matrices (wine and soil) shows consensus between them and clear differences between studied areas. Finally, we applied a canonical correlation analysis, demonstrating significant correlation (r = 0.99; p < 0.001) between soil and wine composition. To our knowledge this is the first report combining independent variables, constructing a fingerprint including elemental composition, isotopic, and polyphenol patterns to differentiate wines, matching part of this fingerprint with the soil provenance.     

Biological nitrogen fixation in Azospirillum strain-maize genotype associations as evaluated by the 15N isotope dilution technique

Few studies of the inoculation of cereal crops with N₂-fixing bacteria have included more than one or two plant genotypes. In a recent study performed in Argentina using 12 different maize genotypes, it was found in 2 consecutive field experiments that several of them responded consistently, either negatively or positively, to inoculation with a mixture of strains of Azospirillum spp. The present study in post was performed to investigate the effect of inoculation of individual strains (and a mixture) of Azospirillum spp., and their nitrate reductase negative (NR-) mutants, on the growth of four of these maize genotypes. Two of these genotypes were grown in ¹⁵N-labelled soil with the aim of quantifying any contributions of biological N₂ fixation. Two genotypes (Morgan 318 and Dekalb 4D-70) produced similar increases in grain yield when they were inoculated with a mixture of Azospirillum spp. strains or fertilized with the equivalent of 100 kg N ha^-1. The other genotypes (Dekalb 2F-11 and CMS 22) showed little response to inoculation or N fertilization. The Morgan 318 and Dekalb 4D-70 genotypes showed a large increase in total N accumulation, suggesting that the response was due to increased N acquisition, but not due to bacterial nitrate reductase as the NR- mutants generally caused plant responses similar to those of the parent strains. Despite problems with the stabilization of the ¹⁵N enrichment in the soil, the ¹⁵N isotope dilution results indicated that there were very significant biological nitrogen fixation (BNF) contributions to the Dekalb 4D-70 and CMS 22 maize genotypes.Dedicated to Professor J.C.G. Ottow on the occasion of his 60th birthday     

Effect of the choice of food composition table on nutrient estimates: a comparison between the British and American (Chilean) tables

Objective: To determine the level of agreement between the American (Chilean) and British food composition tables in estimating intakes of macronutrients and antioxidants. DESIGN, SETTING AND SUBJECTS: Information based on a food-frequency questionnaire with emphasis on antioxidants was collected from 95 Chileans aged 24-28 years. Nutritional composition was analysed using the British table of food composition and the American table of food composition modified by Chilean food items. Mean differences and limits of agreement (LOAs) of estimated intake were assessed. RESULTS: Mean differences between the two tables of food composition ranged from 5.3% to 8.9% higher estimates when using the American (Chilean) table for macronutrients. For micronutrients, a bias towards a higher mean was observed for vitamin E, iron and magnesium when the American (Chilean) table was used, but the opposite was observed for vitamin A and selenium. The intra-class correlation coefficient (ICC) ranged from 0.86 (95% confidence interval (CI) 0.81-0.91) to 0.998 (95% CI 0.995-1.00), indicating high to excellent agreement. LOAs for macronutrients and vitamins A and C were satisfactory, as they were sufficiently narrow. There was more uncertainty for other micronutrients. CONCLUSION: The American table gives relative overestimates of macronutrients in comparison to the British table, but the relative biases for micronutrients are inconsistent. Estimates of agreement between the two food composition tables provide reassurance that results are interchangeable for the majority of nutrients.     

Soil Bioremediation: Combination of Earthworms and Compost for the Ecological Remediation of a Hydrocarbon Polluted Soil

A three-dimensional (3D) off-line chemical transport model (CTM) has been used to study an Arctic ozone minihole event in early December 2002, when the meteorological conditon were severely colder than in recent years. The minimum temperatures were below 188 K on 6 December 2002 and remained below 195 K for the entire month. Such temperatures are low enough for the formation of PSCs (polar stratospheric clouds) which were observed by a visible/near infrared solar occultation instrument by the Polar Ozone and Aerosol Measurement (POAM) III experiment. The SLIMCAT model compares well with the depth and evolution of the ozone distribution as observed by the second European Remote Sensing Satellite (ERS-2) Global Ozone Monitoring Experiment (GOME). The combined effect of a very strong and large intrusion of sub-tropical air, and uplifting of air masses of low ozone concentrations from the troposphere plays important role in the fomation of the ozone minihole. The modelled chemical ozone loss rate was relatively fast in the lower stratosphere in the region of frequent PSCs and higher levels of ClO and BrO. The observed PSCs in the vicinity of the minihole supports the model-predicted location of PSCs and chlorine activation. However, ozone miniholes have been attributed almost entirely to dynamical effects due to its short duration.     

Indole acetic acid production by Rhizobium: Effect of 2-ketoglutaric acid

I ndole acetic acid (IAA) production from tryptophan by cell suspensions of Rhizobium trifolii, R. leguminosarum, R. phaseoli and R. lupini was studied in the presence or in the absence of 2-ketoglutaric acid. In R. lupini, production of IAA was strongly enhanced by the ketoacid, but in fast growing rhizobia it was less enhanced or unaffected. On the other hand, glutamic acid inhibits IAA production by R. meliloti, but stimulates IAA production in both R. leguminosarum and R. phaseoli. A hypothesis is proposed to explain these results.     

Fimbria-like adhesive factor (EAF 44) from verocytotoxigenic Escherichia coli of bovine origin

An adhesin with fimbria-like properties was present in four strains of verocytotoxigenic Escherichia coli isolated from diarrhoeic calves in Brazil.     

2-anilino-3-methylbutyrates and 2-(isoindolin-2-yl)-3-methylbutyrates,two novel groups of synthetic pyrethroid esters not containing a cyclopropane ring

A new series of substituted 2-anilino-3-methylbutyrates has been prepared; bioassay data for these compounds on Heliothis virescens, Musca domestica, Aphis fabae and Tetranychus urticae are presented and discussed. Some unexpected relationships were observed between the nature of the substituents and the biological activity. Increases in foliar stability were noted with certain substitution patterns. Both α-cyano-3-phenoxybenzyl 3-methyl-2-(α, α, α,2-tetrafluoro-p-toluidino)butyrate and the corresponding 2-(2-chloro-α, α, α-trifluoro-p-toluidino)-3-methylbutyrate showed good stability in air and light, and exhibited biological activities of a similar nature and potency to those of previously known synthetic pyrethroids. Esters of the (R)-2- anilino-3-methylbutyric acids are far more active than those prepared from the (S)-enantiomers. The (R)-configuration at C-2 in these acids is sterically equivalent to the active absolute configuration at the chiral carbon α to the carboxylate group in both the permethrin and the fenvalerate types of pyrethroids. A new class of insecticidal 2-(isoindolin-2-yl)alkanoates is also reported. In this series the most biologically active analogue was α-cyano-3-phenoxybenzyl 3-methyl-2-(4,5,6,7-tetrafluoroisoindolin-2-yl)butyrate. These esters were considerably less stable than the anilino analogues on exposure to air and light.