Oil quality and sugar content of peanuts (Arachis hypogaea) grown in Argentina: their relationship with climatic variables and seed yield     

Casini C  Dardanelli JL  Martínez MJ  Balzarini M  Borgogno CS  Nassetta M 《Journal of agricultural and food chemistry》2003,51(21):6309-6313

The ratio of oleic to linoleic acids (O/L) and the tocopherol content are important features in determining peanut (Arachis hypogaea) seed shelf life. Soluble carbohydrates are known to be important precursors in roasted peanut flavor. The chemical qualities of Argentine grain are different from those of other countries, but no previous studies that associate grain quality and environmental parameters have been performed. Relationships were determined between O/L, tocopherol and sugar contents, and variations in temperature and rainfall during the grain filling period of Florman INTA peanuts. Dry seed yield was used as another explanatory variable. Multiple regression procedure gave mean temperature (positive coefficient) and total precipitation (negative coefficient) as the explanatory variables for variations in O/L. Total precipitation and dry seed yield (both negative coefficients) were found to be predictor variables for tocopherol and sugar contents. Total precipitation was an explanatory variable included in all of the linear regression models obtained in this study.  相似文献   

Relationship between changes of soil microbial biomass content and imazamox and benfluralin degradation   总被引：2，自引：0，他引：2  

Costantino Vischetti  Cristiano Casucci  Piero Perucci 《Biology and Fertility of Soils》2002,35(1):13-17

The present research was carried out to determine the relationship between the soil microbial biomass content and the persistence of imazamox and benfluralin in three different soils, incubated in the laboratory under different conditions. The half-life values varied between 17.1 and 92.4 days for imazamox and 11.4 and 37.9 days for benfluralin depending on initial concentration, temperature, soil moisture and soil type. Significant decreases in microbial biomass-C content compared to untreated soil were observed initially, not exceeding 25.0% for imazamox and reaching 64.7% for benfluralin. The microbial biomass-C content then returned to initial values at varying times depending on incubation conditions. The relationship between herbicide persistence and microbial biomass-C content gave parabolic curves (P<0.001 in all cases) under all conditions tested. At the time of maximum microbial biomass decrease, the concentration of imazamox was generally about 50% of the initial dose (except for at 10°C for imazamox, when the biomass began to recover as early as the point when the pesticide concentration was at 60-65% of its initial dose). The final equation proposed could be useful to deduce the decrease in soil microbial biomass in relation to the herbicide level.  相似文献   

Identification and quantification of phenolic compounds in grapes by HPLC-PDA-ESI-MS on a semimicro separation scale     

Nicoletti I  Bello C  De Rossi A  Corradini D 《Journal of agricultural and food chemistry》2008,56(19):8801-8808

Reversed phase high performance liquid chromatography (RP-HPLC) on a semimicro separation scale was employed to develop a straightforward method for the simultaneous separation, identification, and quantification of phenolic compounds occurring in whole berries of Vitis vinifera, which comprise phenolic acids, flavonols, catechins, stilbenes, and anthocyanins. A C-18 narrow bore column of 150 x 2.0 mm I.D. and a semimicro photodiode array detector (PDA) cell of 2.5 microL, in conjunction with a mass spectrometry detector equipped with an electrospray ionization source (ESI-MS) to confirm peak identification, were employed. The C-18 narrow bore column was eluted by a multisegment gradient of increasing concentration of acetonitrile in water-formic acid solution that was optimized on the basis of the results of a study carried out to evaluate the influence of mobile phase composition and gradient shape on separation performance and detection sensitivity by ESI-MS. The identification of individual phenolic compounds was performed on the basis of their retention times and both UV-visible and mass spectra, acquired by a mass spectrometer (MS) equipped with an electrospray ionization (ESI) source, employed in conjunction with the PDA detector. Libraries comprising retention times, UV-visible, and mass spectra for major phenolic compounds expected in grape berries were made by subjecting solutions of each phenolic standard to the optimized RP-HPLC method. Quantification of individual compounds was performed by the external standard method using a six point regression graph of the UV-visible absorption data collected at the wavelength of maximum absorbance of each analyte determined by the PDA spectra. The RP-HPLC method was validated in terms of linearity of calibration graphs, limits of detection, limits of quantification, repeatability, and accuracy, which was evaluated by a recovery study. The developed method was successfully applied to identify the phenolic compounds occurring in the whole berries of nine red and one white grape of different varieties of Vitis vinifera, comprising some autochthonous varieties of south Italy such as Aglianico, Malvasia Nera, Uva di Troia, Negroamaro, Primitivo, and Susumaniello. Large differences in the content of phenolic compounds was found in the investigated grape varieties. As expected, only glycosilated flavonols were quantified, and the total amount of these compounds was higher in the whole berries of red grapes than in the white Moscato, where the most abundant phenolic compound was quercetin 3-O-glucoside. In almost all samples, the most and least abundant anthocyanins were malvidin 3-O-glucoside and cyanidin 3-O-glucoside, respectively, with the exception of Uva di Troia where the least abundant anthocyanin was delphinidin 3-O-glucoside.  相似文献