Temporal Oscillation and Losses of Three Carbon Forms in a Microcatchment of NW Spain     

José Manuel Mirás-Avalos  Montserrat Valcárcel Armesto  Cleide Aparecida de Abreu  Rosane da Silva Dias  Eva Vidal Vázquez 《Communications in Soil Science and Plant Analysis》2015,46(4):296-308

Long-term agricultural sustainability and water quality may be threatened by inadequate land management. Carbon (C) losses at the catchment scale largely depend on land use and management practices. In “Abelar” farm (A Coruña, NW Spain), swine slurry was directly discharged during a period of about 30 years onto agricultural maize fields and rangeland under cattle production. In 1998, the agricultural fields and rangeland were planted to stands of Eucalyptus globulus. The purpose of this work was to assess the concentrations and losses of total, inorganic, and organic carbon at the outlet of a small catchment (10.7 ha) in the period from March 2007 to December 2010. Nearly 190 water samples were collected; specifically eleven in 2007, sixty-eight in 2008, fifty-six in 2009, and fifty-three in 2010. Total runoff volumes from the catchment were also measured during the 3.7-year study period. Except for a peak recorded in November 2008, total carbon values (TC) ranged from 1.51 to 6.14 mg L^?1, total inorganic carbon (TIC) varied between 0.54 and 3.30 mg L^?1, and total organic carbon (TOC) was between 0.38 and 2.83 mg L^?1; the exception was due to an occasional pig slurry discharge occurring in 2008, which drove the greatest values of the three carbon forms. The season of the year influenced concentrations of total, organic, and inorganic carbon. Total, organic, and inorganic carbon loads exported at the catchment outlet were estimated at the monthly and yearly time scales. Overall, 10 years after planting to the forest, dissolved and total carbon losses were rather small.  相似文献   

Effect of High Organic Loading Rates of Particulate and Dissolved Organic Matter on the Efficiency of Shallow Experimental Horizontal Subsurface-flow Constructed Wetlands     

Aracelly Caselles-Osorio  Alessandro Porta  Montserrat Porras  Joan García 《Water, air, and soil pollution》2007,183(1-4):367-375

Two identical experimental subsurface-flow constructed wetlands were operated at relatively high organic loading rates (23 g COD m^?2 day^?1) for 4 months to evaluate their relative ability to remove either dissolved organic carbon (glucose, considered to be a readily biodegradable substrate) or particulate organic carbon (starch, considered to be a slowly biodegradable substrate). The systems were built using plastic containers (0.93 m long, 0.59 m wide and 0.52 m high) that were filled with an 0.35 m layer of wetted gravel (D₆₀?=?3.5 mm, uniformity coefficient C_u?=?D₆₀/D₁₀?=?1.7) and the water level was maintained at 0.05 m under the gravel surface to give a water depth of 0.30 m. The results indicated that there was no significant difference in COD removal between the two systems. Both systems generally had COD removal rates of over 90%, which is quite high if the heavy load applied is taken into account. The removal of ammonium was greater in the glucose-fed system (57%) in comparison with the starch-fed system (43%). Based on mass balance calculations and stoichiometric relationships, it was estimated that denitrification and sulphate reduction were minor pathways for the removal of organic matter. Indirect observations allowed to assume that methanogenesis made a highly significant contribution to the removal of organic matter.  相似文献   

Investigation of the retronasal perception of strawberry aroma aftersmell depending on matrix composition     

Buettner A  Mestres M 《Journal of agricultural and food chemistry》2005,53(5):1661-1669

The development of strawberry aroma aftersmell after consumption in aqueous and milk model systems was followed. A recently developed sensory approach was used to seize the qualitative, quantitative, and temporal aspects of aroma profile development. The results obtained from sensory evaluation were then correlated to analytical data, obtained by means of intraoral aroma detection using the buccal odor screening system (BOSS). A clear correlation was found between the sensory persistence of single odor impressions and the intraoral detectability of odorants by BOSS. For the strawberry aroma mixture it could be shown that BOSS is capable of selecting those odorants of a complex aroma mixture that elicit a certain aftersmell impression developing after a certain period of time in the oral cavity. Also, the changes in in vivo odorant persistence depending on changes in food matrix composition could be directly followed by means of BOSS.  相似文献   

Removal of Zn from Aqueous Solutions by Low-Rank Coal     

Solé  Montserrat  Casas  Josep M.  Lao  Conxita 《Water, air, and soil pollution》2003,144(1-4):57-65

The ability of an immature coal (leonardite) to remove zincfrom aqueous solutions was studied as a function of pH,contact time and concentration of metal solutions.Effective removal of Zn²⁺ was demonstrated at pHvalues of 5–6. Kinetic study showed that the adsorption ofZn²⁺ occurs in two phases: a rapid phase followed by aquasi-equilibrium state attained within the first twohours. The adsorption isotherm was measured at 25 °C, using adsorptive solutions at the optimum pH value todetermine the adsorption capacity.  相似文献   

Use of recombinant cyprosin in the manufacture of ewe's milk cheese     

Fernández-Salguero J  Prados F  Calixto F  Vioque M  Sampaio P  Tejada L 《Journal of agricultural and food chemistry》2003,51(25):7426-7430

A recombinant cyprosin from the cardoon (Cynara cardunculus L.) was assayed and compared with calf rennet in batches of ewes' milk cheese by determining different chemical, biochemical, and microbiological parameters over 4 months of ripening. There were no differences between the two types of coagulants in most chemical parameters, a(w), and pH. Proteolysis was more marked and rapid in cheese containing recombinant cyprosin as coagulant, the soluble nitrogen content of which was significantly higher (p < 0.01) than that of the cheese obtained with animal rennet; at the end of ripening the nonprotein nitrogen of cheese produced with recombinant cyprosin was slightly higher (p > 0.05) as compared with that in cheeses obtained with animal rennet. Microbial counts in the milk used for making cheese were high in most of the groups analyzed. Despite slight differences in counts, the main microbial groups analyzed were similar in cheese produced with both types of coagulants throughout ripening.  相似文献   

Parallel synthesis: a new approach for developing analytical internal standards. Application to the analysis of patulin by gas chromatography-mass spectrometry     

Llovera M  Balcells M  Torres M  Canela R 《Journal of agricultural and food chemistry》2005,53(17):6643-6648

The polymer-assisted reaction of 4-(hydroxymethyl)furan-2(5H)-one (4HM2F) with 21 carboxylic acids using polystyrene-carbodiimide (PS-carbodiimide) yielded an ester library. Four of the esters, (5-oxo-2,5-dihydrofuran-3-yl)methyl acetate (IS-1), (5-oxo-2,5-dihydrofuran-3-yl)methyl butyrate (IS-2), (5-oxo-2,5-dihydrofuran-3-yl)methyl 2-methylpropanoate (IS-3), and (5-oxo-2,5-dihydrofuran-3-yl)methyl chloroacetate (IS-4), were tested as internal standards for the quantification of patulin in apple juice by gas chromatography-mass spectrometry in the selected ion monitoring mode (GC-MS-SIM). The developed method combines an AOAC official extractive step and a GC-MS-SIM analysis. Using a chromatographic column containing trifluoropropylmethylpolysiloxane as the stationary phase and IS-1 as the internal standard, it was possible to perform an accurate and precise quantification of underivatizated patulin in apple juice at concentrations down to 6 microg/L. A detection limit of 1 microg/L was established.  相似文献   

Phenolic Profile and Antioxidant Capacity of Chickpeas (<Emphasis Type="Italic">Cicer arietinum</Emphasis> L.) as Affected by a Dehydration Process     

Aguilera Y  Dueñas M  Estrella I  Hernández T  Benitez V  Esteban RM  Martín-Cabrejas MA 《Plant foods for human nutrition (Dordrecht, Netherlands)》2011,66(2):187-195

This study presents the effects of soaking, cooking and industrial dehydration on the phenolic profile, and antioxidant capacity in two chickpea varieties (Sinaloa and Castellano). Chromatographic analysis identified a total of 24 phenolic components, being isoflavones the main phenolics in raw and processed Sinaloa and Castellano flours. The impact of the industrial dehydration was different depending on the chickpea variety. Although Castellano chickpea exhibited the highest levels of phenolic compounds (103.1 μg/g), significant reductions were observed during processing; in contrast, the dehydration did not cause any further effects in Sinaloa flours. Interestingly, Sinaloa variety showed high thermal stability of isoflavones during processing. As expected, the levels of antioxidant capacity were in accordance with the behavior of phenolic compounds exhibiting noticeable reductions in Castellano chickpea and not relevant changes in Sinaloa chickpea. Thus, the significant occurrence of bioactive phenolic compounds along with the relevant antioxidant capacities of dehydrated chickpea flours make them to be considered functional ingredients for their beneficial health effects, especially in case of Sinaloa.  相似文献   

Comparative study of the cytotoxicity induced by antioxidant epicatechin conjugates obtained from grape     

Ugartondo V  Mitjans M  Lozano C  Torres JL  Vinardell MP 《Journal of agricultural and food chemistry》2006,54(18):6945-6950

We studied the cytotoxicity of epicatechin conjugates obtained by depolymerization of grape polymeric flavanols in the presence of cysteamine or cysteine and the resulting conjugates purified by ion exchange and/or reversed-phase high-resolution chromatography and compared it to their antioxidant capacity. The studies were carried out on fibroblast and keratinocyte cell lines. The cytotoxic effects of these products were observed at concentrations 3-7-fold higher than the antioxidant concentration after exposure for 24, 48, and 72 h. The compounds with a gallate group were more toxic than the corresponding products without one. It is interesting to note that the esther ethyl derivative exhibited low cytotoxicity but had the most potent antioxidant activity. The results indicated that effective antioxidant activity can be obtained from these products in a concentration range that is safe for the normal cell. This finding suggests new pharmaceutical applications and may also help us to identify the potential therapeutic dose.  相似文献   

Nitrogen mineralization dynamics in acid vineyard soils amended with bentonite winery waste     

Isabel Rodríguez-Salgado  Paula Pérez-Rodríguez  Claudia Campillo-Cora  Antía Gómez-Armesto  Manuel Arias-Estévez  Montserrat Díaz-Raviña 《Archives of Agronomy and Soil Science》2018,64(6):805-818

An excess of available nitrogen (N) in vineyard soil is considered detrimental for vine growth, making a thorough assessment of N mineralization dynamics in vineyard soils before the addition of winery waste necessary. This study assesses the changes in N mineralization in acid vineyard soils amended with bentonite winery waste (BW). Non-amended soil (control), BW and soil-waste mixtures (SBWM) with a low (+L) or high (+H) dose of BW were incubated for six weeks. After 7, 14, 21 and 42 days of incubation, the control soils, BW and SBWM were analysed for net ammonified N, net nitrified N and net mineralized N. Parameters related to the kinetics of N mineralization were also determined. The addition of BW increased the potentially mineralizable N (N₀) in the amended soils (58–144% for the highest BW dose), although the mineralization rate was governed by the soil characteristics. Mineralizable N was only a small fraction (<4%) of the total organic nitrogen added to the soil through the BW addition, mainly due to the dominance of the nitrification process in the BW amended soils. These experimental results suggest that the addition of BW may be a suitable amendment for nitrogen fertilization in acid vineyard soil.  相似文献   

Premature losses of leaf area in response to drought and insect herbivory through a leaf lifespan gradientOA     

Sonia Mediavilla  Montserrat Martínez-Ortega  Santiago Andrés  Javier Bobo  Alfonso Escudero 《林业研究》2022,33(1):39-50

Implications of the differences in leaf life span are still subject to debate in the field of ecophysiology. Since leaf traits associated with these differences may be decisive for determining the distribution of tree species, this topic is particularly relevant in the context of climate change. This study analyzes the effects of the differences in leaf life span on premature losses of leaf area owing to insect herbivory and to abiotic stress. Loss of leaf area may be an important determinant of...  相似文献